Originally Published 2014

Cutlass Bearing Removal

Every now and then a boats propeller shafting need to be replaced. A replacement can be necessary due to corrosion, bending, wear at the stuffing box, wear a the cutlass bearing or a poorly installed/machined shaft to begin with.

When choosing a shop to do this work you will need to ask specific questions to ensure you are not getting a subpar job. Many, many shops are more than eager to charge you a huge sum of money only to deliver shoddy work that won’t comply with ABYC P-06. Today, shafting work should only be done using high grade alloys such as:

Minimum Grade:
Aqualoy 17 or Aquamet 17

Mid Grade:
Aqualoy 19 or Aquamet 19

Recommended:
Aqualoy 22 or Aquamet 22

Top of the Line: (typically for high power vessels)
Aqualoy 22HS (High Strength)

Choose your shafting shop carefully!

Getting the Shaft Out

On many boats, especially sailboats,  removal of the cutlass bearing can help you avoid dropping or removing the rudder.  Dropping a rudder is a job easier said than done on many boats. On this vessel, an Ericson 34, the shaft just barely slid by the rudder once the cutlass bearing had been removed. Pressing out the coupling saved many hours of labor time, in not having to drop the rudder to remove the shaft. Of course the shaft for this article was not-reusable due to wear, so we just opted to cut it out.

To remove Cutlass bearings Compass Marine Inc. often uses our Strut-Pro tool. These tools are not perfect and cannot always press out a bearing but the success rate is high enough that the tool pays for itself in just one use.

Before the nitpickers come out in full force, the word “Cutless®” is a trademarked brand name of Duramax Marine. I therefore use the alternative accepted generic spelling of “cutlass”, just like Vetus Marine does. This is so as not to infringe on a trademarked “brand name”.

From the Duramax Marine web site: “Cutless® is a registered trademark of Duramax Marine® LLC.”

Cut The Old Shaft Out

If you know the shaft needs to come out, why risk damage to the gear box or gear box flange by trying to press the coupling off the shaft. It’s far easier and far less time consuming to simply cut the shaft out. Cutting this 1″ shaft took all of about 45 seconds to free the it from the flange and we did not risk any damage to the gear box flange in doing so. This article has more detail on removing a coupling as well as all the precautions:  Installing a PSS Shaft Seal

Slide-Hammers = NO!

Before you engage a boat yard to do this job, I will type this so it hopefully makes sense; NEVER use a “slide-hammer” to remove a shaft from a coupling if the coupling is attached to the gear box!

If you want to throw 3k out the window feel free to use a slide-hammer, if not, use safe and proper procedures for removing the shaft from the coupling such as a coupling press tool like the one from Buck Algonquin pictured below.

Yards that don’t care about your boat or gear box, use slide-hammers to remove prop shafts from the couplings even when the coupling is attached to the gear box. Yes, it’s quick & dirty, and the damage to your gear box can largely goes unseen, for a period of time, but DO NOT be fooled by boat yards with slide-hammers and do not allow a yard to use one on your boat.

Let me phrase this another way. Would you go to a dentist who used a Milwuakee Sawzall to remove a tooth?? No, of course not. To those in the know, a dentist with a Sawzall is the same level of ignorance as a slide-hammer. A slide-hammer is the wrong tool for the job. I know many tech-schools blindly teach this, and they are grossly wrong, but you now have the ammunition, and are a better educated boater. It’s your boat, so just say no to slide-hammers!

What’s so wrong about using a slide-hammer?

A slide-hammer is essentially a long piece of metal pipe that threads onto your shaft where the prop nuts go. It’s about 4 feet long and has a heavy metal weight on it. The weight is slid up the bar, towards the prop shaft nuts, and then thrown or “slid” down the bar until it hits the end and SLAMS to a sudden & abrupt stop. The concept is that it breaks the coupling from the shaft when the weight comes to the sudden and abrupt stop. This tool does what it does very well, but that is not the end of the story. The reality is that a slide hammer destroys gear boxes and brinnels the bearings in the process.

The Damage Done is not Always Obvious

The worst part about slide-hammers is this destruction of your gear is not always readily apparent. Because of this boat yards and their workers assume they get away with it and it “works”. Yes, it works, it works to destroy gear boxes. If your boat yard tells you “we do it all the time” please do yourself a favor and find a new yard.

Slide hammers can cause brinneling of the bearings or races in the gear box. The shock loads imparted on the static bearings, by the “slide-hammer”, actually create flat-spots in the races or bearings themselves. Your gear box may appear to work for some time after the slide-hammer event but eventually, the damage rears its ugly head and it’s next to impossible to lay blame on the slide-hammer user as they rarely fail instantaneously.

About twelve years ago I was at a yard when I overheard the yard-boys slamming & slamming & slamming a slide hammer to free a shaft from a coupling. All of a sudden I heard one last SLAM, then a CLUNK and the sounds of metal bits on fiberglass, then “OH $HIT!”…… You guessed it they hit it so hard they blew the case of the gear box apart and destroyed it. They literally cracked the iron gear box wide open. The shaft, after all the beating that finally destroyed the gear box, was still firmly embedded in the coupling.

Caveat emptor on slide-hammers..

Double Taper Shaft

While many marine shafts, such as those used on many sailboats and small trawlers are a straight shaft at the coupling end, others may be considered a “double taper” meaning the coupling end is tapered just like the propeller end.

As can be seen above, this shaft is a double taper on both ends. Many sailboats however lack the space for a double taper coupling, because double taper couplings are typically longer. Sailboats typically use a “straight coupling”.

The point of this image is to make darn sure you know what type of coupling you’re working on before trying to remove it…

A New Split-Coupling

For tight spaces, like this Ericson 34, Buck Algonquin makes a great split coupling. I typically prefer a straight split-coupling to a straight solid coupling but, both work if properly installed fitted and faced. It is these small nuances of a correct prop shafting job, such as fitting & facing, spotting, chamfering corners etc. that matter most what selecting a shafting shop to do your work.

The nice thing about this split-coupling is that it’s no longer than a standard solid coupling and is actually a touch shorter than most. The “S” designates “short”.

This is the new split coupling from the box above. You can see how compact it is on its overall length. If you have a tight fit one of these may be a good choice.

Fitting the Coupling to the Shaft

The two shims are placed in the “splits” to make the bore ID the same at both ends before “fitting” begins.

I hear it repeated all over the internet boating groups & forums that a split coupling is intended for DIY installations. While it certainly can be installed by a DIY, without a machine shop, it will not be a “correct” fit unless it has been properly fitted & faced to the shaft. Most DIY’s do not own the tools for this type of work.

In this image the coupling is being prepped for “fitting” it to the shaft. In order to do this, the split end of the coupling is shimmed parallel while the coupling is very carefully honed for a light interference fit. “Light interference fit just means the coupling actually requires some force to get the shaft into it. This “fitting” of the coupling to the shaft is just as critical with a split coupling as it is with a straight coupling.

A split or solid coupling that  “slides” onto the shaft = incorrect fit and can be dangerous!

These couplings purposely ship a tad undersized for the SAE shaft tolerances. This allows a competent shafting shop to “fit” the shaft to the coupling. The proper fit for a straight coupling is a light press fit or light interference fit. This means it does not just “slide on” and requires some light tapping, or heat to expand the coupling while it is installed over the shaft.. Getting this level of fit can be time consuming.

Inside Finish, Before Fitting

The inside of the coupling is reamed, then honed to get the final fit.

Rough Reaming Tool

This is the rough reaming tool. The finishing is done with grinding compound or other means of honing the coupling bore.

Flange Is Bored To Fit The Shaft

With the flange held tight in the jaw of the lathe, the reamer is very carefully adjusted and rotated to remove just barely enough material to start to get closer to  a perfect fit. The final fit is done by hand with valve-grinding compound. It takes some time, and a lot of experience, to make it fit just right. This one took about 25 minutes until the fit was just right.

Should Be A Light Press Fit

Here, the machinist is test-fitting the coupling to the shaft. A soft lead mallet is used to gently tap it on. This is not pounding but rather a light “tap fit”. Just enough interference so it won’t go on by hand is how it is done. With a good fit you may need to heat the coupling to make the shaft slide into it when doing the install at the boat.

Shafting Material is Cut To Length

For the shafting on sailboats & most power boats we only specify Aqualoy 22 or Aqualoy 22HS. This shafting is a high-alloy austenitic stainless steel that offers tremendous corrosion resistance and excellent strength properties. It is some of the best shafting there is and is made by world renowned Western Branch Metals.

Here a length of 1″ Aqualoy 22 is cut to length for machining.

Checking Shaft Run Out

Once the shaft is cut to length, it is then tested for run out. A good shafting shop should always do this, even with a brand new shaft. If it does not meet tolerance it needs to be made true. This was was out by less than .001″ for a 52″ shaft. This shaft was also checked for true after the machining process.

Machine for Cutting the Shaft Taper

Once the shaft is cut to length it’s placed in this very expensive machine to cut the taper, or tapers, if it’s a double-taper shaft.

Keyway Cutting Machine

This is the machine used for cutting the coupling and propeller end key ways.

Spotting The Shaft

After the coupling has been fit to the shaft, the set screw hole needs to be “spotted” into the shaft. This like many of the other nuances is a requirement under ABYC P-06. The drill press is spotting the shaft in this picture.

Spotting is the creation of a small dimple in the shaft for the head of the set screw to recess into. If your shaft is not spotted for the set screw/screws you have a poorly machined shaft that does not meet the ABYC marine safety standards. Some unscrupulous vendors do cut this corner.

No Spotting

The above image is a prime example of sloppy machining. This shaft literally fell out of the coupling after a DIY pressed it off and tried to re-use it. The layer of rust that broke free was the fit”. The boat took on enough water so that is was a complete loss and the owner carried “liability only”. He’d spent over $10K on the boat since purchase and it was all gone in an instant because he did not follow best practices. Best practice when a coupling is removed is to drop it at a shafting shop for a “fit check”.  In most instances a removed coupling will need to be replaced. This coupling was clearly never “fit” correctly to the shaft to begin with and then the set screws were never spotted to act as a fail-safe back up. Don’t let this happen to you. Insist on a light interference fit and properly spotted set screws!

Do Not Re-Use a Used Coupling Without a Fit-Check or Fit & Face

This DIY had actually taken the time to read this article. Sadly for him, he chose to ignore the advice on properly fitting couplings. You guessed it, he re-used the old one when he installed a new PSS Seal. He penny-pinched this in order to save approximately $80.00. In the end it cost many thousands in repairs and an insurance claim that wound up getting him cancelled the next year. His insurance premium is now more than double what it had been, every year.  Lets see, spend $80.00 now or $26,000.00 a few weeks later? I call that penny-wise, pound foolish.

Tow to Boat Yard $$$

Haul Out – $$$$

Short Term Storage -$$$$

Labor to Drop Rudder -$$$$

New Shaft & Coupling – $$$$

Prop Repair (prop hit hull & rudder) – $$$

Strut Repair – $$$$

Water Damage Repairs – $$$$$$$ (boat was sinking when shaft backed out)

Rudder Repair $$$ – (prop hit rudder when it backed out of the boat)

Transmission Repair – $$$$

Losing of 85% of the Boating Season = Priceless

Please let the seriousness of cutting corners, when removing a coupling, sink in!

A Spotted Shaft

A shaft made by a reputable shafting shop will have spotting that looks like this;

Facing the Coupling to the Shaft

With all the other work done the coupling is finally installed and torqued properly to the shaft just as it would be on the vessel. The shaft is then spun in the lathe and the face of the coupling is made true to the shaft. This image shows the coupling before the facing has occurred.

Fully Fitted & Faced

Just like a brake rotor lathe the face of the coupling is made to rotate perfectly with the shafting. If you receive a shaft and rotor from a prop-shop and the face does not look “freshly cut” please do yourself a favor and question this. It would be extremely rare that a new shaft and coupling did not require an facing.

Now that you know what to look for you can now be your own best advocate when choosing the right prop shafting shop/supplier..

Good luck and happy boating.

Making Sense of Alternator Frame Sizes & Output Ratings

Aftermarket externally regulated higher performance alternators are generally classed into three basic categories – Extra Large Frame, Large Frame or Small Frame.

The differences in case (frame) sizes can be seen here:

Many marine engines, other than some large Cummins, Cats etc., generally ship with what is called a small frame alternator. Small frame alternators run the gamut in terms of build quality and durability but none of them are what could be considered “constant duty“. The only way I know of getting a constant duty small-frame alternator is to remove the internal rectification and rectify remotely. This is what I have done on my own vessel for charging a large LiFePO4 battery bank.

“RC, What does constant duty mean?“

What it means is the small frame alternator you purchased is simply not a “constant duty rating” no matter who’s name is on it. For years and years, with moderately sized banks of deep-cycle flooded batteries, this did not really matter because the batteries came up to voltage pretty quickly and then the alternator caught a break.  Today I have customers with 600Ah plus battery banks on 30 footers. This may seem insane by yesterdays standards but not by today’s standards. The growth & use of computers, tablets, TV’s and other  iToys over the last ten years has been immense. Today it has many of our customers exceeding the daily energy consumption of their DC refrigeration. Not too long ago DC refrigeration was the huge energy hog today, for many, it is computer, tablet and device use.

Small Frame Marketing Hype

The Real World Reality

The cooked alternator you see below was made by manufacturer of the rather brash statement above. It was marketed in what I would consider to be a grossly misleading manner. This alternator was a small frame, single fan unit and we have seen many of them burned up, from being over-worked while not being adequately temp protected.

Burned up alternators like you see below can happen due to a lack of alternator temp sensing/protection and/or a lack of being able to current limit the alternator. Compass Marine Inc. actually builds the identical alternator using the same internal components from the same manufacturer. We go a few steps further however and build the alternator with 400V 75A diodes. The manufacturer of the misleading claim above used only 200V 50A diodes. Despite the ability of our version to deliver significantly more power, and for longer, we would never, ever tell a customer the Compass Marine Inc., CMI-HD125-ER, is a continuous duty unit. That would be pure unadulterated BS.

This one was charging a large AGM bank and was the second identical alternator to suffer the same exact fate. Two separate but identical alternators completely cooked themselves in a matter of months. The pictured alternator was measured at 367F when the owner had noticed his tachometer stopped working. Upon opening the engine bay a thick acrid smoke hit him in the face. The regulator being used on this alternator had no alternator temp sensor and no way to current limit it. The regulator was replaced with a Balmar MC-612, plus an alternator temp sensor, and current limiting or “Amp Manager” was used. The third identical alternator is still running to this day, 9 years later.

There is no small case alternator we know of that can run continuously at full output.

Anyone telling you otherwise is simply a bovine dung artist

“But RC I bought an XXXXXX brand alternator and it has a hot rating?“

Please let’s not misconstrue the difference between a cold rating & hot rating and a “constant duty” rating. A hot rating and a constant duty rating have no relation to each other at all. In the industry alternators are tested to ISO 8854 or SAE J56. These testing standards help standardize output ratings at a certain RPM, temp and test voltage.

Alternators tested to J56 are simply rated like this:

Test Temp = 23ºC  ± 5ºC

Test RPM = 6000

Test Voltage = 13.5V

Unfortunately this industry standardized testing is not designed nor intended to see how long the alternator can run at full output into a large bank of deeply discharged batteries. In other words, an alternators output rating is rated cold (73ºF to 83ºF) at 6000 shaft RPM and 13.5V. Simple stuff.  While some marine alternator manufacturers, such as Balmar, provide both a cold (79ºF) and a hot rating (194ºF) this hot rating is still not a constant duty rating. The hot rating is simply telling you the expected drop in max achievable output, as the copper in the alternator heats up to 194ºF. A cool alternator simply produces more peak output than one at near 200ºF.

A “Hot Rating” is not a Continuous Output Rating

Why don’t manufacturers supply a constant duty rating? The reason is pretty simple, it’s because every application and engine space is different and providing a continuous rating is nearly impossible to apply across each installation scenario. Below are three examples of measured engine room temps to illustrate why this is not done with small-frame alternators:

Boat #1 Engine Room Temp = 162.4ºF

Boat #2 Engine Room Temp = 171.1ºF

Boat #3 Engine Room Temp = 132.5ºF

The alternator on boat #3 is going to have a much better chance of staying in a safe operating temp range than the Boat #1 or Boat #2.

A cold and a hot rating are simply the short term outputs at 6000 RPM and the rated temp. If your application requires an alternator capable of prolonged continuous duty output there are options.

1. Choose a *higher output small frame alternator and use Balmar’s Belt Load Manager feature to limit maximum output = Easiest / Least Expensive $
2. Choose a small frame alternator but remove the internal rectifier and rectify remotely = Difficult to DIY / $$$$
3. Install a large frame alternator designed for continuous duty use = Difficult to DIY / $$$$$$

* When case size remains the same, the increased output, when choosing a higher output unit is not linear. In other words choosing the 150A model that is also available in a 75A model does not net you double the continuous safe output.

What About Hairpin Small Frame Alternators?

The term hairpin refers to a stator design invented by the Japanese manufacturer Denso. The design places a lot of copper into a small space by using square magnet wire that can nest more tightly. Balmar uses this technology in its AT-165 and AT-200 series alternators. 

Where the hairpin design alternators shine is in better efficiency, which means less heat developed, and for applications where we have a slow turning engine or a need for a high percentage of full output at a low RPM such as charging at anchor or low RPM motor sailing.The hairpin design can produce a lot of current at low RPM.

The AT series really shines for low RPM charging.  However, please don’t be confused into thinking you can run these alternators full-bore into a 1600Ah bank without some sort of temp protection strategy such as Belt Load Manger and an alternator temp sensor. They are still small frame alternators.

In the foreground is a Balmar hairpin stator and behind it a standard wound stator. You can see why the hairpin design can deliver so much current at low RPM when compared to a standard designed stator.

Alternator Mount Styles

For marine applications there are four basic mount styles that make up most of the installations;

1″ Foot – Westerbeke, Volvo, Perkis, Cat etc.

2″ Foot – Perkins, Universal Diesel, Vetus, Cummins, Volvo etc.

3.15″ Saddle Mount – Yanmar & some Mitsubishi/Westerbeke engines

J-180 Saddle Mount – Large diesel engines such as Cummins, Detroit, Cat etc.

1″ & 2″ Foot Mounts – For aftermarket use most manufacturers will build  1″ foot alternator that can easily be converted to a 2″ foot with the addition of a spacer or spacer kit. This makes a 1″ foot alternator one of the most versatile in the industry and it has the widest engine fitment range.

3.15″ Saddle Mount – These frames are also commonly known as dual-foot or Hitachi mount alternators. The popularity of the Yanmar marine engines is so vast that it makes sense for aftermarket performance alternator builders to produce a model that specifically fits Yanmar engines. A saddle mount alternator, such as the 3.15″ style, may also be used in many single foot applications, with careful use of spacers. Saddle mount alternators feature a *drift bushing.

J-180 Mount – The J-180 mount is fond on large frame alternators and is very similar in design to the Yanmar saddle mount. The scale and the ID width is approx 4″ between feet and it uses uses a 1/2″ pivot bolt as opposed to a 3/8″ or 10mm bolt. Saddle mount alternators feature a *drift bushing.

IMPORTANT: Not all alternators, with a similar mount style, share the same offsets and this is why careful installation and proper alignment are critical.

Belt & Pulley Choices

No discussion regarding a marine alternator installation would be complete without discussing belt & pulley choices. Until very recently the marine industry has supplied most engines with single or dual v-belts to drive the stock alternators. The use of a single v-belt was marginally suitable when boats had very little DC load or demand but today many boaters have far exceeded the capabilities of a stock 30-60A alternator and have also often exceeded the capabilities of a 3/8″, 1/2″ or even a 5/8″ single v-belt. Some owners, who’ve been overwhelmed with belt-dust, have increased the alternator pulley size to yield more belt to pulley surface area but, this is a Band-Aid solution that results in poor alternator performance due to reductions in alternator RPM.

“Industry Accepted” Recommendations for V-Belts

• 3/8″ V-Belt = 80A
• 1/2″ V-belt = 100A

This guidance can be a truism, to some extent, but it will require;

•   Impeccable Alignment
•  Near 180 degrees of belt wrap
•  Extremely clean pulleys
•  Relatively short bulk charging duration’s
•  A high quality belt

More Realistic Maximum Amperage Recommendation

• Single 3/8″ or 10mm V-Belt = 70A
• Single 1/2″ or 13mm V-Belt = 85A.

Limitations of V-Belts

Lower HP drive capability – When compared to flat style multi-rib belts

Prone to over tightening – Many a boat owner or marine techs have over-tightened a v-belt in an attempt to minimize slippage or belt dust but in the process damaged a water pump or other accessory drive. Over tightening a v-belt does not really aid in less slippage and can actually have an effect that is opposite the assumed outcome.

Excessive frictional heat – This heat can actually damage the alternators front bearing and transfer excess heat into the alternator. Frictional pulley heat can also be exacerbated by the use of cheap stamped steel pulleys (see image below) which tend to expand the V gap as they heat up. This can cause the belt to become loose under load. Using billet machined pulleys can help to minimize this.

Engine choking belt dust – Many v-belts contain abrasive materials such as Kevlar or Aramid fibers. When these abrasive fibers are turned into belt dust it can actually cause damage to engines. Diesels use and need lots of fresh air for the combustion process and that air needs to be free and clear of abrasive contaminates. The idea that a marine diesel does not need an air filter can be an engine damaging old-wives tale. The image below illustrates why a quality air filter on your marine diesel is a good idea.

Typical Marine Pulley Types

Multi-Rib belts, often referred to as “serpentine belts” or flat belts are a more efficient design and can drive considerably more HP without developing the same level of frictional heat. Flat multi-rib belts approach drive efficiencies of 99%+ where a v-belt is nearly 2.5%-3% less efficient. Even with perfect sizing and loading the v-belt is developing more frictional heat.

For owners who desire more amperage capability from their engines, manufacturers such as Balmar/Alt-Mount or Mark Grasser DC Solutions are now offering custom multi-rib pulley kits. These kits bolt onto your existing engine and are a sure fire way to drive more HP with less belt tension and virtually no belt dust. The Balmar / Alt-Mount kits are usually a 10 Groove or a 6 groove design, depending upon the kit, and the Mark Grasser DC Solutions kits utilize an 8 groove pulley design.

These are the most common pulleys for marine engines rated by effectiveness:

Belt Wrap Considerations

When considering an alternator upgrade the desired amperage and the actual belt-wrap of the existing pulley can’t be ignored. Many alternator belts are also used to drive water pumps, as seen here, and this means the belt wrap around the alternator pulley is going to be less than optimal.  Less than optimal belt wrap usually means your single v-belt will not strictly adhere to the industry max capability recommendations of 80A for a 3/8″ belt and 100A for a 1/2″ belt. These recommendations are assuming a near 180 degree wrap around the alternator pulley. This brand new alternator installation is a prime candidate for a serpentine kit.

Pulley Cleanliness

When upgrading your charging capability one of the best things you can do is to ensure your existing crank pulley, as well as your  water-pump pulley surfaces are clean and free of rust or corrosion. Rust and corrosion act like sand paper on your belt/s and create rapid wear, a need for continual adjustment, and excessive belt dust.  To remedy rusty & corroded pulleys a drill and wire wheel, or a Dremel type tool with wire wheel, can be used to clean the pulleys to bright metal. In this image a water-pump pulley gets a cleaning. You’ll be amazed at the difference this one small step can make.

What About Double-V Pulleys?

Double-V pulleys are pretty common and perform far better than a single-V pulley arrangement but they too can be more problematic than a multi-rib pulley system. If your vessel already has a double-v belt pulley system I would recommend using it, unless you desire more than 130A to 140A of alternator charging. Years ago, when industry used lots of v-belts, finding  a *precision matched pair of belts was pretty easy (*Gates terminology), today, not so much. For the set up pictured below, Gates recommended their Aramid reinforced Predator Industrial Series belts but with limited sizing, in the industrial line, and the inability of the Predator series belts to wrap the alternator pulleys small outside diameter properly, the Gates XL Series was the next best choice.

Gates, Dayco and other belt manufacturers claim that today’s manufacturing process has eliminated the need for “matched pairs“. Interestingly enough Gates still offers “precision matched pairs” for industrial applications customers? If there is “no need for this due to manufacturing” then why? Precision Matched Pairs are actually hand measured and matched but sizing is really quite limited when compared to marine application needs. For a high amperage marine application finding a well matched pair can be difficult at best. Your best bet is finding your largest NAPA, or other large automotive or industrial belt distributor, such as Motion Industries, and choosing your belts by:

•  Same Date Code
•  Same Factory
•  Same Lot Number
•  Closely Matched Production Run Numbers

This is a guide to deciphering Gates numbers and matching the belts as closely as possible:

Pulley Width Considerations

Unless you’re using a Balmar 1/2″ wide pulley, be careful to only use a 3/8″ width pulley if you have a 3/8″ wide belt. Balmar specifically machines their 1/2″ pulley, such as the 61-0010,  a bit deeper so that the 1/2″ pulley can be used with a 3/8″ wide belt. Most other 1/2″ wide single-v pulleys are not machined this way. As can be seen here a 3/8″ belt was used on a 1/2″ pulley and it’s only fractions of a mm away from bottoming out on the flat spot of the pulley. Once this occurs you can burn out the front alternator bearing very quickly due to the excessive heat.

Belt Mistakes Can be Costly

In this image we have a high quality Japanese made front bearing that was literally “burned out” due to frictional pulley heat. The bearing got so hot the front seal was destroyed and the grease was literally cooked out of the bearing. It then began to squeal & howl. If you look close you can see the heat damage emanating out from the shaft side of the bearing seal, and the gap in the seal where the grease was allowed to cook out of it. This was simply a case of attempting to drive too much horsepower with a single v-belt.

Pulley Ratio Considerations

Most performance marine alternators are specifically wound for low RPM performance. This means they can develop a tremendous amount of their rated output at a low engine RPM. At low RPM, for many marine diesels, this means a slower alternator fan speed. Low fan speeds with high output is were some of the most damaging heat can occur. Always pay attention to alternator temp at fast idle, if you plan to charge on-the-hook. If the alternator gets to hot reduce Belt Load Manager and / or add some forced air cooling to the alternator, via ducting and blowers.

Also, each alternator frame has a maximum design RPM. Some older marine engines, such as those by Volvo Penta, had massively large crank pulleys that can result in as much as a 5.5:1 pulley ratio. This can actually result in over-spinning certain alternator frames beyond their max design RPM limit. Before installing any performance marine alternator, on an engine with an overly large crank pulley, please check with the manufacturer of the alternator for the maximum safe RPM. You may find you need to up-size the diameter of the alternator pulley significantly.

Alternator Belt Shields & High Performance Alternators = Not a Good Match

I know we live in a world where lawyers are purportedly waiting around every corner to jump out and sue you into bankruptcy but, the Yanmar lawyers have taken this threat right over the top. The belt shields on newer Yanmars really do nothing but create problems dissipating heat from alternators. If you, as a boat owner, don’t know not to stick your hands into the belt of a running engine by now, perhaps you’ll want to consider a safer pastime. I hear Trivial Pursuit is pretty tame.

Balmar has lawyers too, and they advise drilling out the belt guard for better air flow. This can help but is really just a legal Band-Aid. Internal fan alternators draw cool air in from both the front and rear of the alternator and expel it out the center. Front fan alternators draw air in through the rear and expel it out the front. Belt guards like this do nothing but make it more difficult to have a cool running alternator.

In this image the alternator is sandwiched between a hot heat exchanger and the belt guard… It’s a darn good thing they installed an alternator temp sensor.

The choice to keep, drill or to remove your belt guard is 100% your decision. Please consider the safety risk carefully when or if you choose to remove it entirely.

Alternator Position – In or Out

Here’s an insider tip that can be considered when installing a high output alternator. Ask yourself these questions;

Where the manifold is in relation to the alternator?

Is it right behind it?

Do I have the room to tilt the alternator out a bit and get it away from the hot engine?

On many engines the alternator is designed to sit directly in front of a massive 180ºF to 210ºF heat source called a manifold. This particular engine room was not the best for photography but it illustrates an optional approach.

Here we are using the stock adjuster arm from Yanmar as well as the belt supplied with the serpentine pulley kit. Doing this places the alternator smack dab in front of the hot manifold making it tougher for the alternator to suck in the coolest air possible.

Stock Configuration

The choice was made to use a longer belt and adjuster arm, in this case the Balmar UAA or Universal Adjustment Arm. As can be seen the alternator is now out into cooler air and not stuck behind the hot manifold.

Optional Configuration

This owner really went to town and built his own adjuster arm to get the alternator out into cooler air. This is Balmar AT-200 with Alt-Mount Serpentine kit and the owner made his own adjuster arm to get the alternator out into cooler air.

Don’t be afraid to “roll your own“…

While cleaning the shop I found a template I had used for a custom large frame alternator installation. It was mocked up in cardboard, then 1/4″ plywood and then I made a drawing to give to our local machine shop. The drawings are nothing special. A custom adjuster arm, if necessary, is not very difficult. In 98% of the installations going to this level will not be necessary but it is just another option you have.

We have a few of these arms in-stock as it is less expensive, per piece, to do a run of ten of them than one. It is available at this link to the MHT web store: CMI Universal Alternator Adjuster Arm

Balmar has also made this easier, and less expensive than doing our CMI custom arm above, with the Balmar Universal Adjustment Arm also available in the MarineHowTo.com web store.

Alternator & Pulley Alignment

Perhaps the most critical step in an alternator installation is ensuring the crank pulley and alternator pulley alignment is good (water-pump too it they share a belt). In most cases, with a an upgraded alternator, they will often bolt right in and alignment will be pretty good but, it pays to check it, just to make sure.

We have two things we are looking at;

Angular Alignment Issues

Parallel Alignment Issues

Here’s an example of both an angular & parallel alignment issue:

TIP: If the alignment is so bad you can see it visually, it’s beyond bad!

Checking Alignment On-Board

When on-board, alignment can be checked pretty easily by using a straight-edge. By clamping a known true straight-edge across the front face of the crank pulley, and extending it to the alternator and water pump pulleys we can easily check both angualr and parallel alignment. Parallel alignment is usually the more common issue but, alternator brackets made by the engines marinizer, such as on a Westerbeke or Universal, can tend to create angular issues more often than a factory made alternator mount such as a Yanmar.

For this task I generally use some aluminum “L” stock or 1/2″ square tube stock tested on our cast iron planer table for flatness. Aluminum like this is available at just about any Home center. You’ll want the straight-edge to be able to extend to both the water pump and alternator pulleys. Once clamped to the crank pulley, you can simply measure the offset from the straight-edge to the very edge of the belt or to a pulley groove center. The measurement should match at both ends.

One measurement that is often confusing is when you have a crank pulley and alternator or water-pump pulley’s with varying face thicknesses. It does not need to be confusing. Once the straight edge is clamped to the crank pulley the measurement that’s important is from the straight edge to the belt edge or the center of the pulley V’s. If measuring to the center of a pulley V, on multi-rib pulleys, be sure to use the same v-groove at both ends. A divider can be used to compare end to end measurements by measuring one end then locking it and moving it to the other end. For these illustrations I have used a ruler and edge of belt measurements. Please do not use “to edge of belt” if the belt is not brand new.

This end is a prime example of why the pulley thickness is not taken into account. As can be seen the face thickness of the alternator pulley is less than the crank end. This is why the measurement that matters is from the edge of the straight edge to the edge of the belt or the center of a V in the pulley itself. In the event that the face of the crank pulley is thinner than the alternator pulley a piece of shim stock can be used at the crank end to space the straight edge out beyond the alternator pulley.

For angular alignment the straight edge should be the same distance from the straight edge at both side of the pulley. In the photo above we can see the gap between the pulley and straight edge is perfectly parallel and angular alignment is also not an issue here.

The image below represents a case where the crank pulley’s face is much thicker than the alternator pulley’s face. A measurement was made at the crank end first, from the straight edge to the pulleys second groove and then repeated at the alternator pulley end and the two offsets were compared. The distance was essentially 23.15mm at both ends or darn near perfect alignment..

“What about laser alignment tools?”

We own a couple of these laser tools and all I will say is save your money, unless space is really, really tight.  The tricks you’ve just seen remove the need for these expensive tools and the laser alignment tools do no better of a job. A $3.00 piece of aluminum stock and a ruler or your navigation dividers from your chart table are a lot less than the cost of a Gates Drive-Align Laser or similar.

Shimming & Spacers for Alignment

Occasionally you can run into a situation where the aftermarket alternator is off by a bit. For Yanmar fit alternators the most common need for alignment is to shim forward. This is good because with a dual-foot alternator, if you needed to move aft, you’re either moving the alternator mount or machining off some of the foot.

In this image two washers have been used behind the Yanmar fit alternators front foot to get the correct pulley alignment. The washer closest to the alternator foot was sanded on a piece of glass, using wet sand paper, until the correct thickness was attained. This can take a while but the right thickness washer was just not readily available. If you know the thickness you need a machine shop can also make you any spacer you need. Any washers used for shimming should ideally be the same ID as the alternator pivot bolts OD. In other-words if you have a 3/8″ OD pivot bolt use a 3/8″ ID washer and if you have a 10mm pivot bolt use a 10mm metric washer.

Yanmar 3.15″ Dual Foot – Shim Forward

Dual Foot / Saddle Mount Alternators Can be Quite Flexible

In this image we have a Westerbeke engine that used a teeny-tiny 1″ foot Mitsubishi alternator that really conformed to no “small-frame” standards other than its own. Westerbeke offers a bracket to convert to a Balmar or other 1″ or 2″ foot Delco/Motorola/Bosch frame type alternator but the pricing for this bracket is literally insane.

When a 1″ or 2″ foot alternator can’t work the 3.15″ Yanmar style dual-foot alternators can often be used in place of a 1″ or 2″ foot mount as seen below. This image shows a Balmar 6-Series dual-foot alternator mounted to the factory Westerbeke engine mount (red part). Alignment has been set and  mocked up using shims and washers. Once the shim & spacer dimensions are known you can then hit a machine shop and have them make you the correct spacers in a one-piece design. In this case the multiple pieces behind the red engine mount and in front of the alternators rear foot, would be combined into one nicely machined spacer. You can always leave it as pictured too. I just prefer less shim-parts as opposed to more.  I have noted what I refer to as the drift bushing in the rear foot more on this soon.

Here’s an example of what it looks like to have the spacer and shim pieces machined to minimize excess part count..

Dual-Foot Alternator Rear Foot Bushing

The Yanmar style 3.15″ dual-foot alternators (also called “saddle mount” or “Hitachi mount”)  as well as the 4″  dual-foot J180 large frame alternators both use what I refer to as a rear foot “drift bushing“. It is really just a split bushing that is machine pressed into the rear foot but other than “drift bushing” it really has no identifiable name. It does however deserves some brief discussion.

This bushings sole purpose is to compress the front foot of the alternator between the pivot bolts head and the alternator mount. It also serves to “support” the aft end of the alternator. Under no circumstances should the drift bushing ever be removed and the two feet of the alternator “clamped” by the pivot bolt..

This owner of a brand new alternator did not know what this bushing was for, so he removed it.. Oh jeez…….

This is a saddle mount / dual foot drift bushing:

This image illustrates where the clamping pressure is applied with a “dual-foot” alternator. Only the front foot is under clamping force pressure. The rear foot is merely providing support. You can see pretty easily with this Yanmar alternator bracket why removing the drift bushing can result in breaking of the alternators mounting feet.

When installing a dual-foot alternator following the guidance below will result in a worry free installation:

Alternator Pivot-Bolts

An alternators pivot bolt would appear a rather mundane item to discuss but, using the wrong bolt can get quite expensive. In the image below the engine blocks aluminum alternator mount has been  damaged by the use of the wrong size pivot-bolt. Using the wrong size bolt, one that is undersized, can allow the alternator to twist, under belt-load and can potentially cause damage.

If you let the above continue and ignore checking your belt tension and alternator when you check the oil. This damage destroyed the entire front timing gear cover of the engine.

Alternators are also susceptible to pivot bolt damage:

Adjuster Arm Issues & Solutions

Issue #1

An alternator adjuster arm is normally just a piece of plate steel that connects to the engine on one end and the alternator on the other end. Its sole purpose is to keep tension on the alternator belt. The steel arm is normally slotted, as can be seen below, and the bolt clamps the alternators adjustment ear to the adjusting arm. One problem with this is that the alternator ear is soft aluminum and the aluminum gets pretty hot. Through repeated expansion & contraction cycles, and on high vibration diesels, the bolt can often become loose as happened in the left side image below. In this case the bolt actually fell out completely.

Issue #2

The second issue I see, with fairly high regularity in regards to adjustment arms, is a relatively thin washer trying to apply pressure to the slotted arm. Due to the slot there’s limited surface area to actually grab onto. What often winds up happening is the washer begins to “dish” or “cup”.  Once it does this the original torque/tension is lost and the alternator ear looses its grip on the arm can slip and allow the belt to become loose. The grip on the adjusting arm below was lost when this washer “dished” under load.

Solution’s for Issues #1 & #2

In order to alleviate the issues associated with the images above I recommend using a bolt that will extend all the way through the alternator adjustment ear far enough to accept a washer, lock washer and a nut. A Nyloc or other locking nut is an added benefit here as nylon has a much higher melting point than your alternator should ever see. On top of the longer bolt the use of *an extra thick washer, such as the CMI Grip-It Washer will eliminate washer dishing & arm slippage.

*The Balmar AT-165 uses an extra thick washer on both sides because the adjuster ear has a vertical slot in it. For threaded ears an extra thick washer on the adjusting arm side is all that is usually necessary.

Setting Belt Tension

Just like belt alignment, belt tension is critical for optimal alternator performance. Too much tension is not going to necessarily be better than too having little tension. Both extremes are bad. Guessing at belt tension, using the Binford Mark I Thumb Press Tool,  unless your really experienced with this, is not likely to result in a good outcome. New belts also need to be “run in” and then re-adjusted. In other words don’t just install a new belt adjust it and walk away. You’ll want to run the belt under load for a period of time then make a second adjustment.

The first step in setting belt tension is to identify the longest pulley span as show below.

Once you’ve identified the longest belt span you can click on over to the Gates web site and used their V-Belt Tension Calculator. Simply input the type of belt you have, the belt width and whether the belt is new or used and it will give you a belt tension number to start from.

Now that you know what belt tension you need, use of the Gates KRIKIT tools can be used to measure the actual belt tension. A pencil styl tool can also be used but they are more difficult. The Gates KRIKIT tools are inexpensive and pretty easy to use.

Just place the tool in the middle of the longest span, align it in parallel with the belt and press until you hear/feel it “CLICK”. Now carefully remove the tool and read where the plastic arm is flush with the aluminum gauge. There are two Gates KRIKIT tools one goes to 160 pounds and the other to 320 pounds. The most useful for our applications is the KRIKIT II PN 91132 (bottom tool in image below).

Balmar Serpentine Belt Tension:

For Balmar AltMount J10 belts, these are adjusted similarly, by deflection, but not to the same spec as a v-belt. With a 10-groove J-section belt, the correct tension is 1/32” of deflection, for each inch of belt span between pulleys. Deflection pressure is 25 pounds applied in the middle of the longest span. A “pencil type” deflection tester, such as the Gates 7401-0076 is used to test for the 25 points of deflection.

Setting Belt Tension:

For placing tension on the belt I am pretty old school. I still use, nearly 90% of the time, a pry-bar with some heavy duty heat shrink over it. It works really well and the heat shrink prevents scratches on engines and alternators. You just need to find a good point to land it on the engine and alternator.

At the shop here, we also own a product called a Supco Belt Jack. This one, shown on top in the photo below, is the shops fourth and last one. I find this tool entirely under-designed and woefully inadequate. Hopefully this can save you some headache and money. This one is brand new because the last three broke where the pulley pad meets the jack. The welds seem to fail no matter how careful you try to be with it. Even when they do work, and it will for a short period of time, I still prefer the old school pry-bar method. If you feel you want a belt-jack, to adjust your belt, one can easily be made from an old turnbuckle for a lot less money. Done correctly it will likely also be considerably more robust than the Supco Belt Jack.

The best & easiest way we’ve found to adjust alternator belt tension is with the Balmar UBB – Universal Adjuster Arm With Belt Buddy. This is an excellent addition to any alternator upgrade you’re considering tackling.

Good luck with your project and happy boating!!

Preface

This article contains three separate videos that show how to physically program Balmar regulators. The videos are meant to be watched in conjunction with reading this article so the misconceptions and misunderstandings I have identified over the years, regarding these regulators, can be explained with a bit more depth.

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UPDATE: Since this article was written Balmar’s new MC-618 regulator has been launched. The new MC-618 allows programming via the screen on the Balmar SG-200 battery monitor or via the SG-200’s Bluetooth App. It can also be programmed the same way as this article describes.

The Magnetic Reed Switch

For years I’ve listened to customers express concerns about “how difficult it is to program the Balmar regulator“, and I don’t necessarily disagree with this, especially if you’re a DIY or one who does not do this on a regular basis. Even for myself I can find programming a customers, already installed, Balmar regulator a bit tedious.

This article will help:

• Give you higher a comfort level in programming these regulators
• Clear up some of the confusing language in the owners manual
• Provide you with a “Regulator Programming Cheat Sheet“
• Discuss best practices for programming & installing these regulators
• Provide tech tips that will make the process easier.

This article features the Balmar MC-614H but programming & features are similar for the Balmar ARS-5H.

IMAGE: Pictured here is the Balmar MC-614’s magnetic reed switch location, as identified by the red dot.

Definitions: The Balmar owners manuals covers what the LED screen codes mean such as A1C, FFL, AGL etc. etc.. There is no need for us to repeat what is already in the manual in terms of what the numbers/letters are telling you, unless we believe them to be confusing. We have addressed the most commonly confusing parts of the manual, based on years of supporting these regulators, in the article. Please familiarize yourself with the owners manual before reading this article. With the manual and this article it will make more sense.

MC-614 Owners Manual .pdf Download

Why Choose a Balmar Regulator?

Why do I prefer to use the Balmar regulators vs. the other external regulators that are out there? FEATURES! There is no other external voltage regulator, other than DIYing your own, that compares feature for feature with the Balmar regulator. Balmar also delivers excellent customer service and tech-support where humans, that actually know something, answer the phones.

Reliability:

Despite what you you may read on the internet, even by me, because I had an early failure of an ARS-4 & experienced a few others too, these regulators today are very reliable. Over the last 11+ years and many hundreds of regulators I’ve had one regulator with a bad reed-switch (replaced immediately) and one the customer claimed was faulty, but when sent back, was in perfect operational order. Due to changes made over the years to improve reliability, this regulator underwent a full suite of testing, and I got a report from CDI/Balmar. This level of testing was done because these failures are now so rare.

Early on there were some failures of ARS-4’s and some MC-612’s but changes were made to make them more reliable in the move to the current generation. Since CDI Electronics purchased Balmar they have been even further refined for the ultimate in reliability.  I’ve not experienced a single regulator failure under the new CDI/Balmar ownership.

Programming & Control:

In today’s day and age there is simply no excuse for any DC charging product that uses “dip-switch” type programming. By dip-switch I mean programming that utilizes a typical three setting;  AGM, FLOODED or GEL setting. DC charging products like this, in today’s day and age, are simply antiquated tube TV era products. They really have no place being sold in this century other than to pick your pocket. Please do your best to avoid “dip-switch” set battery chargers, solar charge controllers and external voltage regulators that do not allow you to have full-control over your charge settings.

There are no commercially available external regulators, at this price point, that allow you the same level of programming & control that a Balmar does.

• Base Battery Type
• Belt Load Manager (can also be used for current limiting an alternator)
• Display Mode
• Alternator Failure Advisory
• Regulator Field Start Delay
• High Voltage Limit
• Compensation Limit
• Bulk Voltage Limit
• Bulk Time/Duration
• Absorption Voltage Limit
• Absorption Time/Duration
• Float Voltage Limit
• Float Time/Duration
• Low Voltage Limit
• Field Threshold % Bulk to Absorption
• Field Threshold % Float to Re-Absorption
• Alternator Temperature Threshold Limit
• Battery Temperature Threshold Limit
• Battery Compensation Slope Voltage Correction

The majority of the programming features above are non-existent on other external regulators.

Regulator Installation Best Practices

Balmar regulators use an epoxy potting to keep the regulators printed-circuit-board clean, dry & free from corrosion. Placing it in high-heat areas can increase the risk of the epoxy potting to crack, as shown. I prefer to see a maximum working temp of below 140F, but Balmar claims the regulator can now handle 194F with the newest potting epoxy revision.

The regulator in the image above was installed by a boat yard, yet it was installed in the engine bay and only inches from the exhaust riser & manifold. The high heat and rapid temp changes caused the epoxy potting, which makes the regulator highly water resistant, to crack. The cracks in the epoxy likely causing one of the traces or components on the PC board to fail.

This regulator was also located near the engines siphon-break and had some corrosion starting on the terminals. This regulator was replaced and relocated outside the engine bay. After replacing it we ran the boat for other purposes and I noted a surface temp where the regulator used be of 208F. This failure is not a result of the regulator but rather a very poorly chosen installation location.

Regulator Installation Worst Practices:

• Avoid installing the regulator in the engine bay unless yours runs pretty cool
• Do not install the regulator in a hot compartment or against the inside of a dark colored hull
• *Do not wire regulator negative to the back of the alternator
• *Do not wire voltage sense to the back of the alternator
• Do not just set a battery type and walk away
• Do not forget proper over-current protection / fusing
• Do not clean the epoxy potting with any solvents
• Do not use Velcro to affix your regulator to the vessel, there are four screw holes for a reason

Regulator Installation Best Practices

• Install the regulator in a cool & dry location, quite often this will be outside the engine bay
• *Wire positive & negative voltage sensing directly to the battery being charged or as close as possible
• Always use the advanced programming menu to get an optimal set up
• Always program the alternator specifically for your batteries
• Program the regulator at home rather than once installed, it give you much better control
• Always use the optional battery temp and alternator temp sensors (MC-614H offers two battery temp sensors!)
• If you need to extend the wiring harness make one yourself rather than adding onto the factory harness with hidden splices
• Always program your regulator to avoid dropping to float too early. I call this “premature floatulation“
• Always use proper crimp tools & terminals
• Always use over-current protection on any positive feed to the regulator Reg B+/red, #9 / v-sense and Brown / ignition
• Try to mount the regulator in a vertical orientation
• Maintain a decent distance from RF noise emitters such as the alternator itself, inverters, chargers etc.
• Allow for adequate air flow around the regulator
• Use the Balmar supplied magnetic screwdriver, it has the correct magnet strength for the reed switch.

*Please read this sister article on proper voltage sensing for the best charging performance.

Alternators & Voltage Sensing – Why It Matters

Installation Location

Over the years Balmar has had some varying advice on where to best install the regulator. This particular manual for an MC-614 (see image) says to avoid engine bays due to high heat. I tend to agree with this particular manual, unless your engine bay runs cool and is well ventilated.

The MarineHowTo.com Regulator Programming Cheat Sheet

*Click on image to enlarge

In order to help make the job of programming a Balmar regulator easier, MHT created a programming cheat sheet just for this purpose. This .pdf file allows you to print it, then go through each setting before hand. You simply choose what you want to change/set and enter it into the cheat sheet before you start programming. The cheat sheet follows the MC-614’s scrolling menu.

TIP: When you’re all done programming the regulator, please save your programmed settings by inserting the “programming cheat sheet” into your on-board owners manual. Now any service tech that gets on board will know exactly how your regulator is programmed. They will really appreciate this information and it may just save you a lot of time and money.

IMPORTANT: Please purchase batteries from manufacturers who can provide you with all the parameters necessary for proper programming.

This is a free printable .pdf download:

Regulator Programming Cheat Sheet Download – Click Here

Custom Cheat Sheets:

If you would like us to create a custom cheat-sheet for you, the flat fee is $65.00. Before you contact us please read the following;

1- We only do custom cheat sheets for genuine branded batteries such as Lifeline, Trojan, US Battery, Northstar, Odyssey, Crown, Deka/East Penn, Rolls, Fullriver etc.. We do not make cheat sheets for batteries sold by “sticker application companies” such as auto-parts stores, West Marine, Costco, or cheaply made off-shore batteries such as Renogy or most any non USA made battery sold on Amazon. If the sticker on your battery is not an actual physical battery manufacturer, please do not contact us for a cheat sheet.

2- We DO NOT make custom cheat sheets for LiFePO4.

3- You must provide us with a complete description of how you use the boat, daily Ah consumption, all charging equipment including brand, make, model and amperage. Also, if you have an externally regulated alternator we will need to know what belt you are driving the alternator with and the amperage of the alternator.

Regulator Cheat Sheet Example

*Click on image to enlarge

In this image, and downloadable .pdf, we have an example of a regulator cheat sheet all filled out and ready to program the alternator for a GEL battery. This is simply an illustrative example of what a filled out programming cheat sheet might look like.

Regulator Programming Cheat Sheet Example Download

Why is Belt Load Manager a Tremendous Feature?

Belt Load Manager, formerly known as Amp Manager, is a feature unique to the Balmar family of regulators and is built into both the MC-614 and ARS-5. It is programmed using bEL in the regulator programming menu. I know of no other external regulator, other than Wakespeed, that offers any way to limit the alternators current output to accommodate a belt limit situation or to reduce the chances of the alternator from over-heating.

Lets use this alternator as an example:

This owner replaced his 80A factory alternator with a 110A Balmar, only his existing regulator was not a Balmar, but rather a an older Xantrex/Heart Interface. This was a very bad idea. The old Xantrex regulator, like most others out there, had no way to limit the alternators amperage output to better match the v-belts capabilities. The belt on this engine was a 1/2″ or 13MM single v-belt, the standard belt for this engine. Using the factory 80A alternator belt dust was tolerable but two factory alternators burned up trying to feed the massive bank of AGM batteries so the owner sought higher performance.

Once the owner switched to the 110A Balmar alternator he began chewing up alternator belts at a rate of one belt for every 16-22 hours of engine run time. Wow!!!! The belt dust was literally choking everything including the alternator. Alignment was spot on, pulleys were clean and rust/corrosion free and the belt wrap on the alternator pulley was actually quite decent too. The problem was simple, he was just overloading the belt and had no way to limit this issue other than dual v-belts $$$$, a serpentine pulley kit $$$$, or a better designed regulator $$. The owner chose a Balmar regulator and belt manager was set to level 5. Belt dust was nearly eliminated and he went three years on the next belt. Ideally this situation required dual v-pulleys, or a multi-rib / serpentine kit, but with the Balmar regulator and Belt Load Manager, he was able to make it work and at a much lower cost than a pulley conversion.

IMPORTANT: Just because you purchase a 100A alternator don’t be fooled into thinking this is its maximum output. When cold a typical performance based small case alt can pump out 5%-15% more than its face value cold rating or 105A to 115A +, for short duration’s, even with a 100A rated alternator. Some brands will deliver more than 20% over the rating when cold. This overage, even for short duration’s, wreaks havoc on belts. Only Balmar regulators offer the Belt Load Manager feature.

Belt Load Manager can be used to solve two important issues:

#1 Limit an alternators output to better match the v-belts HP drive capabilities.

#2 Limit an alternators output in high demand/long bulk situations to allow longer alternator life by running it at less than “full bore/full output”. Contrary to popular misconception I know of not a single small case alternator that can be run at full output for hours on end, unless;

1. The rectifier has been removed and the unit is rectified remotely
2. It uses liquid cooling
3. You are directly force feeding it ice cold air while also exhausting the hot air

For example, if your desire a hot alternator output of 85A – 100A then you would ideally want to purchase a 120A or larger small case alternator and use Belt Load Manager in order to limit the alternator output to your target amperage. Sizing this way keeps your alt running cooler and keeps it within its safe operating envelope, in regards to a safe working temperature.  Again, only Balmar regulators have the capability to limit the alternators field potential.

IMPORTANT: Small frame / small case alternators, even those sold as high performance, are NOT CONSTANT-DUTY RATED.

Don’t be fooled by less expensive regulators which lack features and lack the programming the Balmar regulators have.

Belt Load Manager Misunderstandings?

Below is a direct quote from the Balmar manual:

“The MC-614 provides the ability to manage regulator field potential, making it possible to govern the horsepower loads placed on the drive belt(s) by the alternator. The Belt Load Manager can also be used to protect the alternator from extraordinary load created by a battery load that’s too large for the alternator’s capacity.”

I have highlighted the words “field potential” for a reason and that reason is because Belt Load Manager (BLM), and how it actually works, is very often misunderstood.

Each step in BLM results in a 5% reduction off the maximum available field potential (click the image to enlarge it). It’s important to understand that BLM is not a 5% reduction in amperage output on a 100A alternator, or a 20% reduction in output for a 150A alternator making the 100A a 95A alternator and the 150A alternator a 120A alternator. This is not how it works, but it’s how many folks assume it works.

What is Often Assumed or Misunderstood

*100A Rated Alternator

BLM #1 = 95A Alternator

BLM #2 = 90A Alternator

BLM #3 = 85A Alternator

BLM #4 = 80A Alternator

BLM #5 = 75A Alternator

*100A alternator used as example only

The reality is this is not how BLM works. We have RPM, rotor core resistance, battery voltage, cold alternator windings and hot alternator windings etc. all playing a role in its overall output and field demand.

As an overly simplified example, consider BLM this way;

If your alternators field could pull max of 6A, at a given RPM, field voltage & stator/rotor temp, and you then set the regulator to BLM #1, the field potential (field voltage), the alternator could see, based on all the previous criteria, is reduced by 5%.  This 5% reduction, in avaible field voltage, would result in less than 6A driving the rotor.

What is “Field Potential”?

Field potential, for a Balmar regulator, is battery voltage (sensed voltage) minus about a 0.4V to 0.5V drop across the regulator FET’s. So a battery voltage of 13.5V, during bulk charging as voltage is climbing, results in a field potential of about 13.0V to 13.1V. If we follow Ohm’s law, voltage is what drives our current, and the same is true into a alternators rotor. BLM reduces the available field voltage, measured after the FET’s, by 5% for each step. If we reduce field voltage (field potential) we also reduce field current and alternator output *generally goes down.

*Generally - Occasionally a single BLM step will not reduce output because the regulator is slightly over-driving the rotor to begin with.

Keep in mind that if you set up belt manager, into a hot alternator,  it will still produce more current when it is cold. If you set it up at a low RPM it will be different than at a high RPM.

Bottom line is that BLM is a reduction in the avaible field potential (field voltage) not a reduction in alternator output based on it’s “rated output”.

There are a few ways you can program this:

•      Reduce BLM in steps, over a few week period, with good solid runs in-between that would be sufficient to generate belt dust. Reduce BLM until you no longer have belt dust or you are no longer bouncing in and out of alternator temp limiting.

•     Beg borrow or steal an inverter that can load your alternator to its maximum output and set your engine at cruise RPM. Now use a DC clamp meter or other ammeter to measure alternator output amperage. While the engine is running reduce BLM until you are at your desired maximum output at cruise RPM. It will still be higher when the alt is cold but not for very long. If concerned about cold start load, reduce BLM by one more step.

Belt Load Manager is just PWMing (pulse width modulating) the field output during periods that would otherwise result in 100% regulator field output.

Program The Regulator Off the Boat

One of the easiest ways to program a Balmar regulator is at home, with a 12V source. It is simple, and requires only 4 wires for the MC-614, or 3 wires for the ARS-5. You’ll also want a fuse or fuses to do so this safely. In this image I’m using a small 12V GEL battery. I use this battery for testing mast wiring during spring commissioning. I have added a fuse block and three fuses; Ignition, Regulator B+ and regulator Volt-Sense plus the yellow regulator B-/Negative lead.

Programming the regulator, in comfort, is much easier, less stressful and you can easily double or triple check your work all while not having a hose-clamp tail piercing your backside. I pre-program every single Balmar regulator I install, here in the shop, before I even get to the boat.

Required Connections for Bench Top Programming:

Regulator B-/Negative – Yellow or Black Wire Terminal #1

Regulator B+/Power – Red Wire Terminal #2

Ignition / Brown Wire Terminal #3

*Voltage Sensing – Terminal #9 (*MC-614 only ARS-5 does not have a terminal #9)

IMPORTANT: Battery or source voltage must be at a minimum of 12.5V in order to program the regulator & have the changes save.

TECH TIP: Please fuse all positive wires (+ volt-sense, B+ & Ignition). Hooking the regulator up backwards, without fuses, can destroy it.

Programming The Base Battery Type

It is best to tackle the programming in three distinct steps with battery type being first:

1- Program the base battery type; bA

2- Program the next three settings of the hierarchical menu; bEL, dSP & bDL

3- Program the Advanced Settings

In the first video the MC-614 is programmed for the base battery type or bA:

The reason for programming the base battery type first is to prevent confusion down the road.  Let’s assume you left the regulator programmed to UFP or “Universal Factory Program” but then went in and created a full custom charge profile, in the Advanced Settings menu for your GEL batteries. The first thing a tech will do, when there is an issue, is to look at the UFP setting, then look at your GEL bank, and change the battery type to GEL. They may do this despite the fact that you have proactively changed the GEL or AGM or FDC settings in Advanced Programming, to exactly match your brand & type of battery. Correctly setting the battery type just prevents confusion.

The Programming Hierarchical Menu

The menu you see in this image represents the top line menu items that you’ll scroll through to program the regulator. Each hierarchical menu item is a gateway to change what that top-line menu represents.

TECH TIP: You do not need to go through each step each time. For example, if you made a mistake setting Belt Load Manager or bEL, but everything else is correct, release the magnet after “PRO” appears, then re-touch at bEL to set or change Belt Load Manager. Once you’ve fixed bEL just let the display scroll three times until you see SAU, which means SAV or SAVE, you’re now all set.

Hierarchical Menu In Scroll Order

bA = Set Battery Type –  The gateway to set battery type eg; AGM, GEL, FLOODED etc.

bEL = Set Belt Load Manger Percentage – The gateway to set BLM eg: level 4 is a 20% reduction in field potential

dSP = Set Display Mode – Two choices, long display or short display

bDL = Alternator Failure Advisory – Two choices ON or OFF

 — = Advanced Programming – The gateway into advanced regulator Programming which features 15 customizable parameters

This second video examines the hierarchical menu of the MC-614 Regulator:

The third video show how to use Advanced Programming

TECH TIP: For batteries such as LiFePO4 you may find it necessary to reduce the bv setting below the default low of 14.1V. When using the regulators menu in scroll-order this is not possible because Av is set to 14.0V and each step must be 0.1V apart. There is however a work-around for this.

If  you wanted to set bv to  13.9V & Av to 13.8V you would need to reduce Fv first, then Av and then you can reduce bv. Each constant-voltage stage, bv, Av or Fv, needs to be programmed with a 0.1V spread. In other words bv can not be set lower than Av or Fv. The work-around is simple, just start backwards by reducing Fv first, then reduce Av then set bv last. Now you can drop the bv, Av & Fv target voltages lower than the factory defaults allow for.

bv = Bulk Target Voltage

Av = Absorption Voltage

Fv = Float Voltage

Confusion Creates Communication Issues

“RC I am fed up with this piece-o-crap alternator.It is in “bulk” and this damn thing is only putting out 20A. How can I send it in for repair?”

The above quote is a typical day in my world. Because the manual and charge lingo Balmar has chosen are confusing at best, trouble shooting time is burned up over perceived issues that are not real all due to semantics.

This all really boils down to two things.

1- Boaters generally understand that “bulk charging” means maximum output from the alternator.

2- Balmar calls a constant-voltage or voltage limited stage of charging “bulk voltage”.

Once voltage is maintained at a constant limit by the voltage regulator ACCEPTED CURRENT DECREASES. Once at constant voltage “bv – bulk voltage” the alternator is not at maximum output. The Balmar charging graph above, and on the right side, has been edited to show what really happens before we attain bv or “bulk voltage”.

Balmar only shows two things happening before constant voltage;

START DELAY

SOFT RAMP

In reality it’s really;

START DELAY – In this stage the regulator is applying 0% field to allow oil for circulation in the engine

SOFT RAMP – In this stage, a max of about 2 minutes, the field (regulator blue wire) is gradually ramped up to the maximum so as not to “slam” the engine with a huge load all at once.

*BULK CHARGING – During bulk charging the alternator is delivering everything it can, in current, to the battery bank. This can take as little as a few seconds for a bank already at high SOC or as long as multiple hours for a large bank deeply discharged.

*This is essentially an entire stage of charging (bulk stage) that Balmar left out of the graph. It is part of what leads to the confusion.

Understanding Battery Charging Lingo

The marine charging equipment industry apparently likes to keep customers “confused“, especially on topics surrounding battery charging. I suspect this is because it keeps the mystique of the “complex wizardry“, that goes on inside the product, a big secret?

In the marine industry almost all manufacturers use what is referred to as CC > CV charging, and this includes Balmar. The DIN standard designations for  charging would be I > Uo > U.

CC>CV charging simply means: Constant Current then Constant Voltage

Constant Current = The maximum current the charge source can deliver to the batteries

Constant Voltage = Voltage is held at a constant value by the regulation circuitry

In the rest of the world there’s actually a DIN standards that defines the charging process and it looks like this; I  Uo  U

I = Constant Current, CC, Bulk or sometimes called Boost Charging

Uo = CV/Constant Voltage, Constant Over Voltage, Absorption, Acceptance or sometimes Topping Charge

U = CV/Constant Voltage, Float, Finishing Charge or sometimes Maintenance Charge

It is important to note that under all definitions, whether DIN or the US terminology bulk charging is not governed by voltage being held steady, it is limited only by the charge sources output capability. During bulk charging, using real definitions, not made up definitions by a marketing department, voltage is always rising during bulk charging.

BULK = MAXIMUM CHARGE SOURCE OUTPUT WITH VOLTAGE RISING

“RC can an alternator really deliver a constant current?”

The answer to this is essentially no unless the alternator and RPM are held perfectly steady and the temp of the alternator stays the same. Despite myself and many others often referring to bulk charging, with an alternator, as “constant current” it’s probably better described as the alternators maximum current potential.

An alternator is affected by many things that a typical fixed-current battery charger is not. An alternator needs a maximum RPM to deliver it’s maximum current output. As an alternator heats up its winding’s lose efficiency and it’s current capabilities drop off a bit. This is why an alternator, or solar for that matter, is really better described as a maximum current potential charge source during bulk charging.

All maximum current potential means is that the alternator is being driven as hard as it can be, by the regulator, and it’s delivering its maximum current potential based on RPM and temperature. The alternators maximum current potential will vary up and down based on RPM, temp etc. however, it is still bulk charging and voltage will always be climbing towards the constant voltage limit. Because Balmar leaves bulk-charging off of their “stages” chart, and the description in the manual is a bit misleading, it can be quite confusing for the average DIY and even marine techs. Whether you choose to call it; bulk charging, maximum current potential, constant potential,  constant current or “I” it’s really just a matter of preference. In any of these scenarios voltage is ALWAYS RISING to the CONSTANT VOLTAGE limit. It’s far more simple to just call it bulk but some manufacturers have muddied those waters, including Balmar by calling a Constant-Voltage stage “Bulk Voltage”.  Perhaps a better and less confusing term for Balmar’s “Bulk Voltage” stage would be “Absorption 1”, but I digress….

Bottom Line? DURING BULK-CHARGING BATTERY VOLTAGE ALWAYS RISING!

IMAGE = BULK CHARGING: In this image we have a hot 110A small case alternator, held at a steady cruise RPM, and it’s delivering a steady 85A of output (red line). As we can see by looking at the blue line the battery voltage is steadily climbing from the 12.1V it started at (approx 50% SOC) and at the end of BULK-charging it has finally approached the regulators 14.7V Constant voltage limit or the Absorption or Uo stage where voltage will now be held steady by the voltage regulator.

Balmar regulators essentially have two absorption or Uo stages and they are called bV and Av. Balmar’s terminology for BULK CHARGING is “Soft Ramp“… Confused? You should be because it makes little sense based on industry accepted terminology.

Constant Voltage Charging

Now that we have gone over what bulk charging is, it’s also important to know what CV/Constant Voltage charging is.

Constant Voltage = Uo, U, Absorption, Acceptance, Float & Equalization

All of the above words are examples of voltage being held steady or a CV stage of charging. DIN separates Absorption from Float by designating absorption as Uo where the “U” means constant voltage and the  “o” means over voltage. The “o” in Uo just means that this CV stage (absorption) can not be held indefinitely or over-charging will result.

The Uo or absorption stage of charging (bv and Av for the Balmar regulators) is one of the most critical charge stages to battery cycle life. The job of the absorption stage is to bring the battery to full charge or very near and to reconvert the lead sulfate, created during discharge, back into active material. The DIN term “U” means Float and lacks the “o” because float can be held for longer periods with minimal risk of over charging.

US Lingo For Three Stage: CC/BULK > CV/ABSORPTION > CV/FLOAT

DIN Lingo for Three Stage: “I”/BULK > “Uo”/ABSORPTION > “U”/FLOAT

To simplify this even more try to consider a voltage regulator as  a VOLTAGE LIMITER. All a voltage regulator is really doing, during CV charging, is limiting to a preset voltage point, once the battery bank has attained the targeted voltage.

IMAGE = ABSORPTION CHARGING: This graph is just a continuation of the charge process started in the previous image. To the left we can see the current still steady at 85A (max alternator current output) but the voltage is climbing up to the pre-programmed voltage limit of 14.7V.

Once the battery bank has attained the voltage limit, in this case 14.7V, the regulator switches / transitions from bulk/max current potential to constant voltage charging where the voltage limit of 14.7V is now held steady by the VR. The voltage regulator is now doing it’s job as a “voltage limiter” instead of just driving the alternator to its maximum potential output.

In the graph you’ll notice that once voltage is held steady the current begins declining. This current decline is simply the result of the relationship between terminal voltage, current & SOC (state of charge). In order for the regulator to hold voltage steady, with a climbing SOC, the current being fed to the battery has to decline or the voltage set point would be over-shot. During absorption charging (bv or Av) the battery is dictating what the current can be so as not to “over-shoot” the 14.7V limit. As the SOC of the battery increases less and less current is needed to not over-shoot the voltage limit.

Key Points:

#1 During bulk charging the amount of current available to a the bank determines the bulk duration.

*High Charge Current = Shorter bulk duration and a CC to CV transition point at a lower state of charge

**Low Charge Current = Longer bulk duration and a CC to CV transition at a higher state of charge

*A Lifeline AGM Battery bank charged at 40% of Ah Capacity (160A for a 400Ah bank) will be bulk charging for around 20 minutes. This means the maximum bulk duration is pretty short, the alternator is only at max potential for about 20 minutes and the rest is CV charging where current is steadily declining.

**If we cut the above charge current in half, and charge the same bank at 20% of Ah capacity (80A for a 400Ah bank), the bulk charging duration lasts about an hour and fifteen minutes. Asking any small-frame/small-case alternator to produce its maximum output for 1:15 is pretty tough and it will develop tremendous heat. This is why Balmar offers Belt Load Manager and an alternator temp sensor. Please use them if you have a large or high acceptance bank.

#2 During absorption/CV charging it is the battery that determines the time it takes to get to 100% SOC. The only way to change this relationship would be to increase the target voltage but most batteries have a reasonable limit as to the maximum target absorption voltage.

Programming Tips to Maximize Your Investment

IMAGE: This image is from a reputable deep cycle battery manufacturer and shows their suggested charge voltages for a 12V battery. The 12V battery at 77F  is highlighted by the blue arrows. Also note the temp compensation they show in this grid. The temp compensation for this brand is all based on a 5mV compensation (per cell) for each 1°C change in battery temp. If your battery manufacturer can’t provide this information, walk away.

Are you charging your deep-cycle batteries at the optimal voltages for a long cycle-life?

The Balmar regulator is an excellent tool for battery charging but sadly far to many of these regulators are not programmed to work as effectively as they can. These tech-tips can help.

TECH TIPS:

1- Small-Frame Alternators are Not Constant Duty – If you have a small frame alternator and a large bank please use Belt Load Manager AND an alternator temp sensor. Your alternator will last much longer when not pushed to it’s maximum every time it is used.

2- Setting Only bA / Battery Type is Inadequate Programming – Setting a base battery type, and walking away, is about as useless as buying a Bugatti Veyron Super Sport and then installing some 1940’s bias-ply whitewall tires.  You’re simply not getting your money’s worth out of the regulator by doing this.

3-  Use Alternator & Battery Temp Sensors – These regulators are not complete until you install the alternator temp sensor MC-TS-A, and the MC-TS-B battery temp sensors. Unless you bank is very small, in relation to the alternator, then an MC-TS-A will be a necessary insurance policy. Every battery manufacturer on the planet prefers temperature compensated battery charging, and most reputable manufactures require it. A Trojan battery that charges at 14.8V at 77F – 80F can not charge at 14.8V at 95F. Without a battery temp sensor you run a much higher risk of cooking your battery and causing accelerated plate erosion.

Battery temp Compensation Slope Adjustments: The battery temp compensation feature on the Balmar regulators is adjusted using the SLP or SLOPE feature  in the advanced programming menu. This allows the regulator to be programmed for exactly the temp correction the battery maker specifies. One area where folks often get confused is in thinking it is only adjustable from 0-8.3 mV per battery. The 0-8.3 mV is per cell and for a 12V regulator this is 6 cells.

In other-words the regulator setting is adjusting temp compensation slope on a per cell basis, in degrees Celsius, not based on 6 cells or a whole battery. If a battery manufacturer wants 0.002 mV per-cell, per-degree C, this would be 0.012V per battery, per degree C change, but the regulator would be set to 0.002 for slope per cell and would compensate the battery at 0.012 mV per degree C change because it knows it is a 12V regulator and automatically multiplies your setting based on 6 cells.

4- Avoid Premature Float – Setting an adequate absorption/CV duration, (time spent at constant voltage), is critically important to battery health. The factory settings of 18 minutes for bv and 18 min Av plus any “calculated” additional time are not going to help you get the most from these regulators. In a perfect world the “calculations” that can extend or shorten the CV time calculations would work perfectly, unfortunately they rarely do, and this is why there is an advanced programming menu. B1C (bv duration) and A1C (Av duration) can be extended or shortened in the advanced programming, and should be in almost every installation other than LiFePO4.

The algorithm for bv and Av works like this: Programmed time completed/elapsed, regulator field percentage below 65% (or what ever you’ve set it too), voltage has been stable for 2 minutes. Once these three criteria have been met the regulator can now move to the next stage. Please bear in mind that the alternator has NO CLUE what percentage of the field is being used to power on-board loads or to charge the battery! This is exactly why you will need to custom program it so you are getting your money’s worth.

As noted above B1C and A1C time settings, % field and voltage stability (why correctly wired volt sensing is critical) must be achieved before the regulator can move to the next stage, and this is most often a good thing. The factory “base battery type” settings allows for the regulator to drop to float far too early, and I say this with nearly 30 years of experience with these regulators as well as using them as teh default regulator on our alternator testing machine here at Compass Marine Inc… Unless you routinely motor for 6+ hours, when out cruising, you should rarely, if ever, see your regulator drop to float. If it is doing this, you can fix this in the advanced settings menu by extending the minimums on the B1C or A1C time clocks and / or adjusting the field percentages that allow a transition. The only parameter that cannot be changed is the voltage stability the reg is also looking for.

I will often set bv at 0.1V over max factory recommended absorption voltage for 6-18 minutes, depending upon battery type, then set Av to the maximum allowable absorption voltage for anywhere from 2 hours to as much as 5+ hours depending upon the bank and available charge current.

On 3/21/18 I capacity tested a 2014 100Ah TPPL AGM battery that has been charged “properly“. Properly defined as a minimum of .4C in charge current (40A for a 100Ah battery) per manufacturer minimum current guidelines. Bulk-voltage bv is set to 14.8V bv for 12 minutes, then to 14.7V Av for 5 hours. This is 5:18 at constant voltage, temp compensated and an alternator float of 13.8V. The other charging equipment on the boat is solar, set similarly but a 2 hour absorption vs. 5 hours (due to the low current), and with float set to 13.4V.

The battery delivered 96.54Ah out of it’s 100Ah rating. A month earlier I tested a 2016 version of the identical battery. It had been charged only by a stock Hitachi alternator only. It delivered 56.83 Ah’s. The correct absorption voltage and a long enough absorption duration matter and can make big differences in bank longevity.

Yes, the Balmar regulators “try” to maximize and deliver a correct constant voltage duration but, in most cases, they fall short and drop to float far too early. The reason for this is simple, all the regulator knows is voltage and % of field drive. Voltage is simple, but the % of field drive actually being used to charge the batteries is nothing more than a crap-shoot guess for the regulator. What I mean by this is the regulator only knows a voltage, as sensed by regulator + sense and regulator B-, and the percentage of field output. What if 60% of that field output was being used for a water-maker, refrigeration, inverter, or other house loads? What if there were no house loads on at all? What if they turn on and off throughout the charge cycle? You can spend lots of time messing with field percentages but they change and you may not be happy with the results.. The easiest way around premature float is to extend the constant voltage time parameters in either b1c or A1c.

“So what’s the bottom line?”

If your regulator is dropping to float before the batteries are accepting less than 1% – 2% of Ah capacity, at ABSORPTION voltage (NOT float) then it is dropping to float too early. Most AGM’s are between 0.5% of Ah capacity (Lifeline) and 0.3% (Odyssey, East Penn/ Deka etc.) of Ah capacity to use tail current as when to drop to float.. Control this via b1C or A1c or field percentages, if you decide to experiment with field percentage. Extending the A1c duration is generally the easiest method.

Charging Batteries Correctly is Critical

5 – Set Yourself Up For PSOC Success – Using the highest absorption voltage the battery maker allows for will result in the least PSOC (Partial State of Charge) damage to the battery. Even the fastest charging AGM batteries require approximately 5.5+ hours to go from 50% DOD to 100% SOC, and this is in lab conditions with no chance of premature float and with 20% to 40% of Ah capacity in charging current. Flooded & GEL batteries charge even slower so absorption times will need to be adjusted to suit the batteries. The worst efficiencies for charging are from 85% SOC to 100% SOC and this duration alone, the last 15%, even with AGM batteries, often takes 3 – 6+ hours depending upon battery state of health. In the ideal set up your batteries don’t drop to float until they are 100% full. With voltage regulated charging this is tough but we can certainly do better because the MC-614 and ARS-5 regulators can be programmed eight ways from Sunday with ample opportunity to minimize premature-floatulation.

6 – Over Charging Concerns – If you’re concerned about “over-charging” when you leave the dock “fully charged“, which is really more of a personal problem rather than a real problem, simply install a dash switch that interrupts the regulators brown wire or ignition feed to shut it down. If you want to further complicate a relative non-issue you can use a resistor in the battery-temp compensation circuit to trick the regulator into a lower voltage by making it think the battery is hot. I call this trick “switch triggered float”..

I’ve autopsied piles and piles of batteries, both sealed and non-sealed, and the number of “dried-out” VRLA batteries (GEL or AGM) I have seen have been an n=2 banks. Both of these banks were ruined by controller-less solar systems (no charge controller at all) pushing 15+V every day. These batteries were not ruined by voltage regulated alternators leaving the dock at 100% SOC. By far and away the biggest concern with marine batteries is chronic under charging. The Balmar regulators can be programmed to help you avoid this.

7- Utilize Balmar’s Advanced Programming Menu – If you’re not taking advantage of the advanced programming features, ones you’ve actually paid for,  you’re really only seeing a marginal, if any, gain in actual charging performance.

8- Wire the Voltage Regulator Correctly – I hear lots of belly-aching over short bulk charging. In every single case of this I find the voltage sensing circuit wired INCORRECTLY. In regards to charging performance, even the Balmar manual is incorrect on how to properly wire voltage sensing. This article cannot be over-looked: Alternators and Voltage Sensing – Why it Matters

9- Field % Transition Thresholds – For a DIY, with not a lot of electrical experience, I generally advise extending b1c and A1c time clocks and leaving the Field Percent Transition Thresholds, FbA (Bulk to absorption) and FFL (from float back to absorption) alone. However, please don’t take this as a blanket statement and don’t be afraid to experiment with the field transition percentages. They are easy to re-set to the factory default, if what you changed does not work.

The difficulty with field percentage transition thresholds is the regulator has no idea what percentage of the field is being used for charging the batteries and what percent of field is being used to power on-board house loads. It is, after-all, a voltage regulator not a current regulator. If your house loads are very predictable, you can easily get the field transitions to work well, but it may take some experimenting and time to dial it in just right. If you run large inverters while under way or have unpredictable loads, while charging, it may be tougher, but please don’t be afraid to experiment with it.

10- It’s All About the Correct Voltages – For years the flooded deep cycle battery industry was stuck in the dark ages as to how to correctly charge lead acid batteries that were used in a PSOC environment. This is because industry and stationary systems require slightly different charge profiles than do PSOC use situations. Today, thanks to folks like Tom Hund (retired), of Sandia National Laboratories Photovoltaic Department, we now know that in order to correctly charge deep cycle flooded batteries we need significantly more terminal voltage during absorption than the antiquated 14.1V to 14.4V old-school guidance used to suggest.

Sadly no-one has keyed in the majority marine charge equipment manufacturer’s about this “breakthrough” information. In their defense, we’ve only known this for 20 or so years. (grin) With a Balmar regulator you can program to your hearts content and get it right.

If you’re not charging deep-cycle flooded batteries at 14.6V (bare minimum) to 15.0V, for PSoC use (boats, RV’s or off-grid solar), they’re simply not getting properly charged. Even many AGM batteries are capable of being charged as high as 14.7V and their health is vastly improved by doing so. With all that said, use your battery manufactures recommended voltages but stick to the maximum of the safe-range not the low side. For example if your battery maker suggests an absorption setting of 14.4V to 14.8V you’ll want to be at 14.8V end of the spectrum not at the 14.4V end.

Proper Programming, It’s Your Choice

IMAGE: Pictured here is a typical automotive voltage regulator the type found on most marine engines as they ship from the factory. I busted it open and extracted all the potting material so you could see the difference. With this image it is easy to understand why an external regulator, with all the features the Balmar’s offer, can lead to better and healthier charging for deeply cycle batteries and to better protection for the hard working alternator.

In the end it is your boat, and you’ll need to decide how you want to program your regulator, for your own piece of mind. All I can say, as a marine energy management specialist, is that I find far too many external regulators inadequately programmed & wired for the owners to be “getting their money’s worth”. Get your money’s worth and venture into the advanced settings!

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Happy boating!

Does an empty marine fuel tank condensate/fill with water when left empty?

Image: On 5/31/2013 This tank was installed on the second floor of my barn with a vent to the outside. The vent was installed just feet from the fuel tank vent on my own vessel as can bee seen out the barn window.

For many years, likely exceeding 37, I have always drained our boats fuel tank each winter and re-filled it in the spring with fresh fuel. I would simply burn the old fuel, or what was left, in our homes oil-fired boiler. The fuel never went to waste and it never got a chance to absorb moisture by sitting in the tank over the winter. Storing the boat empty also gives me an opportunity to see the inside of the tank, check the bottom for debris, and look for any signs of pitting or corrosion. I can also effectively clean it as needed. In all those years I’ve not once accumulated any water in the empty fuel tank over the winter.

So what prompted this experiment? This statement from an internet boating forum member:

“An empty tank will condensate and fill with water! A full fuel tank is far better than leaving it empty.”

Having been doing this for years, I already knew this statement to be untrue, as related to the marine fuel tanks on the boats. I figured I would just set up an experiment to see if there was even a shred of truth to the accumulating water in an empty marine tank theory, that was so factually stated in the quote above.

FACT: Even the fuel in a full tank can reach a “saturation point” where it can absorb water into the fuel. With no fuel inside the tank, this can’t happen, because there is no fuel in the tank to absorb any moisture/water.

Is an Empty Tank Even Realistic?

I know it’s not very realistic for most boaters to empty a tank in the winter. For me, with a sailboat, I also did this with my commercial lobster boats, it was a no brainer and is actually quite easy. For many boat owners this will require a fuel pump and pick up that can reach the lowest part of the tank as well as a place to use or get rid of the fuel that came out. The oil fill fitting for our homes heating system is just feet from our stored boat and is able to be pumped directly from the boat into the 275 gallon oil tank, so for me this is a very easy task.

At the behest of one of the investigators at Practical Sailor Magazine, who were testing the H2Out vent line filters, I purposely left my tank with fuel in it (partial fill) for two winters. I never noted any visually quantifiable change in color of the H2Out beads. I have now gone back to an empty tank each winter even with the H2Out filter.

I now have an H2Out vent filter and Racor Lifeguard LG100 installed to keep my fuel contents drier when the tank does have fuel in it.  Still, for me, my #1 preference is to 100% drain the tank each winter.

Not considering myself an expert in this field, I did as I usually do, I created a real world experiment to see what happens.

What I used for this experiment:

#1 An empty, clean and dry 20 gallon aluminum marine fuel tank

#2 All ports plugged except for the 5/8″ vent line

#3 Hole drilled in my barn to outside for the vent line

#4 Environment where temp changes rather dramatically = Second story of the barn with a black asphalt roof

The barn certainly sees temp swings. The second story is not insulated and has a black asphalt roof. In the winter I often heat the barn by 60 or more degrees in just a few hours and in the summer temps on the second floor can exceed 120F and nights might be 45-50F. The swings are actually far wider than that of our boat seen right outside the window, and this is due to the black asphalt roof.

In order to make this as real world as possible I used a real boats fuel tank, a standard 5/8″ vent hose and vented it to the exterior. Forget jars or simulated tanks, when you have a real tank, why not use it. I also placed it as close to our actual boat as I could.

Over the last 14 months the low temp was -17F and the highest recorded temp was 131F. The barn has no insulation on the second floor thus the 131F temp.

Our boat, when stored, is approx 100′ from Casco Bay/ the Atlantic Ocean so the humidity here is pretty intense.

Results?

Tank Vent on outside of Barn:

Yes, the tank is still sitting there in the barn. It’s been over 8 years since I set this up. I’ve randomly spot-checked the tank on 7 separate occasions since setting this experiment up. To check it I remove the fuel sender and send some colored paper, on a stiff but bendable wire, into the tank. I rub all the walls and tank floor/ceiling areas that I can get to. As of yet, every single attempt at finding condensation has come up bone dry.

Does an empty marine fuel tank condensate…..?? This one doesn’t, at least for the first eight years. (grin)

Spot Checks:

EDIT 9/13/2013: Checked tank for the first time: Results = Bone Dry

EDIT 5/18/14: About two months ago I set it on some 2″ thick stone pavers as some surmised that the tank needs to remain cool as it would if in the belly of a boat at ocean temp. Up here in Maine, when hauled out for the winter, there is no “ocean temp” but I placed it on the “slower to change temperature” stone pavers anyway to satisfy a few doubting boat forum members. Results = BONE DRY….

EDIT 6/25/14: Just checked it again, after setting it on the pavers. Not even a hint of moisture. I chose to check it yesterday because humidity levels have been in the 90%+ range and night time temps have been dipping to the high 40’s 47F – 49F and day time barn temps have been reaching 118F! That is approximately a 70F swing with 80-90% humidity. Results = Bone Dry

EDIT 10/22/15: Topic just came up on one of the sailing forums and it prompted me to go check the tank again. Just finished a very hot summer and now we are seeing temps into the 20’s at night and 60’s during the day. Tank interior is still 100% bone dry. Considering the tank has been here since March 31, 2013 and today is October 22, 2015 I think it is safe to say an empty sailboat fuel tank will not “magically” fill with water. Results = Bone Dry

EDIT 7/24/17: Cleaning the barn and noticed the tank. Figured I would do another spot check. Results = Bone Dry

EDIT 6/3/2019: Looking for parts, saw the tank, and gave it a spot check. Results = Bone Dry

EDIT 5/27/2021: Believe it or not, this tank is still here and has been since 5/31/2013 or just over 8 years! Results = Bone Dry

I suspect 8+ years is a pretty solid data-set for illustrating that an empty marine fuel tank does not magically make its own water. This is why I personally prefer to leave my fuel tank empty, even while some owners prefer full.

Only you can decide what works best for your boat…

This Came Out of a Boat Stored Winters in Maine

I got a call from a customer who felt his motor was running a little hot in the fall and thought he should address it during the off season. We decided to pop the caps off the heat exchanger, check it out, and take it from there.

I popped off the heat exchanger caps on a warm Maine early spring day and wow. The first thing I noticed was a very diluted color, of the propylene glycol in the heat exchanger. I captured some and took a cup of it home to test it with my sight refractometer. The freeze point was around 25F on a test strip but the refractometer reading was actually worse than the test strips and the refactometer is far more accurate.

I called the customer to inquire about the winterizing process. The owner had decided to undertake the winterizing himself in the fall, and told me: “I sucked in 2 gallons of -50 RV antifreeze.“..

Just two gallons, d’oh…..???

I now needed to pressure test this HX. After removal and pressure testing it was discovered the heat exchanger had frozen and split in the tube pack. The low temp that winter had been about -14F..

A repair job like this costs a fair amount of money, certainly far more than sucking in an extra gallon or two of -50 RV antifreeze. Think about this the next time you decide to suck in; “until you see pink“….

Westerbeke, the maker of this engine, suggests an entire 5 gallon bucket.

RV antifreeze/propylene glycol is not intended to be diluted and should always be used at full strength for the best freeze protection. When diluted the freeze and burst points rise rapidly, because a -50 product is already diluted from the factory..

When in doubt suck in another couple of gallons or test it.

Testing the Propylene Glycol

Test strips are not my first choice in testing PG antifreeze concentration, but they are ok and can work. I used these test strips for illustration purposes because photographing through a sight refractometer is nearly impossible.

You can not effectively test PG antifreeze with an ethylene glycol tester. A sight refractometer is the best method but they are pricey. The good thing about a sight refractometer is they are also very, very accurate for testing the specific gravity of a battery so you kill two birds with one stone by owning one.

Far to often I hear; “I just look for pink out the stern and shut her down.”

While pink may show up, and you may “see pink“;

• What was it’s concentration before and after?
• What is the burst point?
• Did you test it for freeze or burst?
• How did what came out the exhaust compare to what came out of the bottle?
• Did you bother to catch any “pink” to compare it for at least color?
• Did you test it?

While you may see pink it does not necessarily mean you are protected against freeze damage for a real cold snap.

Water flow through a strainer, hoses, HX and water lift muffler is not a simple complete displacement event. What you pump in gets mixed & diluted with whats already in there. -50F or -60F Propylene glycol should not get diluted or you will drastically raise your freeze and burst points. The -50 products are already heavily diluted and -50 is the burst point for metals not the freeze point.

The burst points for plastic are usually about 30F higher than for metals. Today many vessels ship with plastic sea strainers.

Add just a little water, through dilution, and your burst point raises very quickly to ranges we see up North in a regular winter.

I once watched a strainer while sucking in 5 gallons. The bottom of the strainer was still clear water at 3 gallons and by five gallons it was full purple. And this was at the intake strainer.

I know from testing that it takes a minimum of five gallons through our 44HP engine and RW circuit to get the same burst points out the stern as what it went in as. I also pre-drain the strainer which holds about 32 oz. The only way to know your burst point is to physically test what comes out or simply suck more in for added insurance.

Some engines will take less and some take considerably more. I depends a lot on the internal flow characteristics of your engine. We see plenty of freeze problems up North from too little AF used or improper winterizing techniques.

At $3.99 a gallon it can be a lot less expensive than freezing your strainer, raw water pump or heat exchanger.. Invest in a test kit then you’ll know exactly how much your motor takes.

How do I test?

The absolute easiest method is to use a sight refractometer. These can also be used for testing the specific gravity of a flooded battery (actually my preferred tool for SG readings). The best way to use a refractometer is to take a baseline sample of the AF you are going to use. Look through the sight glass and read it. This is your baseline number. Now suck in one gallon of AF and capture a sample in a cup out the exhaust. Compare it to the baseline reading. Does it match?

What comes out the exhaust should match perfectly what went in. If you need more suck in another gallon and test again. Once you have hit your match, same in as out, you know exactly how much your engine takes to be adequately protected.

Every spring I deal with frozen and split heat exchangers, water heaters, valves etc. all from owners allowing the concentration to become far too diluted.

NOTE: Winterizing raw water cooled engines very often requires the removal of the thermostat for effective freeze protection. If unsure consult someone who knows your engine well.

Found The Problem

The good news is this owner now has a new heat exchanger. The bad news is it cost him a lot more than a couple of extra gallons of antifreeze would have…

I also found the cause of his cooling issues, zinc crud. Change your engine zincs often or they can shed and plug your HX.

Don’t Forget The Ethylene Glycol

Over the years I have come across many engines that were very diluted on the ethylene glycol side. Heat exchanger leaks can cause this. Another possibility is an owner who added straight water when the sealed cooling system got low.

Before winter be sure to test the ethylene glycol or sealed side of the cooling system. No winterization of an engine is complete without this simple test.

The Prestone testers, like shown, are dirt cheap and work satisfactorily for ethylene glycol (Prestone/Peak/Dex Cool type antifreeze). They can not however be used for propylene glycol.

Good luck & happy boating!