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Old 03-03-2015, 09:04   #31
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Re: Most practical way to upgrade Yanmar alternator?

Not sure if they come in the footprint you need, Have you checked out the big Leece Neville alternators? Really robust....
many of the Balmar and others I have had didn't look any different than a typical Prestolite truck alternator.... small case, same size bearings and the diode set was matched to the case. I assume the ones they sell now are actually bigger better stuff as noted above, but haven't had one.

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Old 12-03-2015, 09:00   #32
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Re: Most practical way to upgrade Yanmar alternator?

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Old 12-03-2015, 10:11   #33

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Re: Most practical way to upgrade Yanmar alternator?

Many good points. I vaguely recall the Chrysler/Dodge police/taxi packages, which always had whopping huge dual=belted alternators, were also perhaps Leece Neville big-frame alternators. Most auto makers (and that is the reality of mass-market alternator market) insist on small frame alternators, because there's not much space under the hood and every inch of that is still "wasted" on the buyer.

Recreational boaters basically got whatever the builders could source CHEAPLY to sell boats at a competitive price. If I can build and sell my brand of boat for $200 less than your brand and they "look" the same...guess who makes the sale? Even on a $40,000 boat, which was a lot back in the 60's and 70's. After that, it is already an industry fixed to legacies.

Small frame integral-regulated alternators are popular for a reason. They're good enough and cheap enough for the mass market they are aimed at. There are bus and truck alternators and large frame alternators, sure, but they are such a smaller market really, look at how big a market "recreational cruising sailors" is. Might as well ask for size 17 triple-A narrow pink high heels in the shoe store. Oh wait, no, I wanted, well, a brighter shade of pink that one won't do?

One automotive maker perhaps said it best when they said the automobile alternator is not designed to charge batteries. It is, rather, designed not to overcharge batteries during day-long road trips. Put that in a boat and it still works the same way, after eight hours under power, the battery still won't be charged. Much less overcharged.

So the bottom line is that in the uncommon event that a boat owner understands the problems, has some budget, and is willing to buy a better solution? The solutions are there, but like those pink size 17 high heels, you may have to look around to find them. And since every one of them will probably reflect ONE engineer's ideas as to what is "best" and "most likely", it should be no surprise that they'll often be different.

You want a cheap suit? You go to a warehouse store. You want something better? It takes a little more time, effort, and yeah, money. I'd call Balmar's role as something akin to the higher-end rooms at Barney's, as compared to Hitachi being more like JCPenney. To some folks, there's no difference. Others, well, simply require a bespoke tailor.
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Old 12-03-2015, 10:50   #34
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Re: Most practical way to upgrade Yanmar alternator?

Originally Posted by svlamorocha View Post
Many thanks; correciton taken on the Lifeline inrush current and everything understood and agreed, except that I am still trying to find an alternator with all that good stuff but for $400 or $500 instead of Balmar's $1000. I have not been able to get a quote from Rod aka Maine Sail but have one from Mark Grasser. Both of them make "marine hot rated alternators" that do everything you and I want.

The question left is: Do any CF members have experience with marine alternators from Maine Sail or Mark Grasser and how do they compare to Balmars?
I haven't bought an alternator from Maine Sail but have bought a couple of other things from him. He provided quick delivery and answered several questions after installation. I'm a happy customer. I would install anything I bought from him exactly as instructed.
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Old 12-03-2015, 10:54   #35
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Re: Most practical way to upgrade Yanmar alternator?

Originally Posted by svlamorocha View Post
I do understand how regulators work and I can find many affordable regulators that will do well what I need (regulate absorption voltage and protect the alternator with temperature sensing) and more or less well something I do not need (switch to float) because of the way I use the boat.

My post is about alternators because I know that the Yanmar Hitachis have weaknesses (for cruising use) that no regulator can fix (namely for a given charge current they heat too much and do not withstand high temperature). The only reason I have not moved away from Hitachis so far is that I was not prepared to pay Balmarīs price for a hot-rated 100A alternator with 3.15" saddle mount and connectors for external regulation.
Let's get back to the basics:

Here's why the Hitachi (NOT Yanmar) alternators don't work so well: (This has been posted a gazillion times all over the internet by Maine Sail)

Hitachi/Yanmar Alternators: (by Maine Sail)

Some alternators though, such as those made by Hitachi and found on Yanmar diesels, are dumber than a pound of beetle poop. Actually, to the alternator, they are pretty smart but to your batteries and the speed of charging they are flat out stupid. Why?

Hitachi alts with dumb regulators, and some others, limit voltage but also reduce voltage based on alternator temperature. This is a self protective feature installed in the internal dumb regulator to prevent the alternator from cooking itself. Remember voltage is the pressure that allows more current to flow. So, if we reduce the absorbtion voltage, then we also reduce the current the alternator is supplying.. The battery simply will not accept the same current at 13.4V that it did at 14.4V and as a result the alternator will run cooler. What do you suppose this does to your batteries over time.......?

The problem is that when cold you will get 14.3V to 14.4V out of the Hitachi but as the alternator heats up the dumb regulator begins to reduce the CV/voltage limit based on the alternators internal temperature. It is not uncommon to find a Hitachi alternator at 13.4V when hot. This is REALLY, REALLY DUMB....

If you have a dumb regulator, and notice the voltage dropping, it is likely a temp compensated dumb regulator. Get rid of it or plan to buy new batteries more often.

If you have a temp compensated alternator or a Hitachi alternator on a Yanmar you really are in dire need of external regulation if deep cycling a larger battery bank.

This is from:

Musings Regarding External Regulation -

and this, too:

Hitachi Alternator and Smart Regulator Instal Question


If you want 80A out of an 80A alternator, you're gonna have problems. Why? 'Cuz it'll overheat. Regardless of what your automobile alternator does in terms of voltage, its rating is far higher than the load that is placed upon it.

Not so with boat alternators. Newer battery technologies allow higher charging amperages since battery acceptance is much higher.

For example, our wet cells of 390 ah at 50% SOC will only take about 60A, and I installed a 100A alternator. If I had AGMs or another new gen battery technology, that load would be MUCH, MUCH HIGHER at 50% SOC. My SYSTEM would not work, then.

I also use the Small Engine Mode from our Balmar MC-612 external regulator. I did not include battery or alternator temperature sensing. Here's why:

Alternator heat, Regulator Controls, Small Engine Mode

Alternator heat, Regulator Controls, Small Engine Mode

Small Engine Mode - discussion with link to the picture of the toggle switch: Alternator heat, Regulator Controls, Small Engine Mode

I essentially do it manually. MOst good electricians recommend temp sensing.

That's why temperature regulation (better than the Hitachi internal) is always suggested for a good electrical charging SYSTEM.

You can't just swap alternators without understanding the SYSTEM and how you want to or need to run it.

There are other alternator sources, like Leece Neville, best prices from ASE Supply Outlet Store Call Bob there, but order online for the pricing.

Leece Neville used to make the alternators for Balmar, but not their newer Series 6, which Maine Sail says is a good piece of equipment.

Good luck. There's a LOT more, but I can't type it all in one post or one day.

PS - If you type "Hitachi" in this forum's search engine, you can find and read the original thread that Maine Sail posted this info in. It's also the second link in the Hitachi story above.
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Old 12-03-2015, 11:46   #36

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Re: Most practical way to upgrade Yanmar alternator?

I'm totally guessing, but "with all that good stuff but for $400 or $500 instead of Balmar's $1000." I'm not sure that's possible. I suspect that the cheapest way to get new prime alternator parts (complete frame, rotor, bearings, not remanufactured but actually new) would be to buy new alternators. From whatever prime maker.

And then (children leave the room now) to literally open them up and THROW OUT the existing inadequate diode frames, regulators, frame and rotor windings.

Replace with heavier diodes, heavier wire in the windings, etc. as needed.

And given that an OEM alternator, really new not re-anything, can retail at $600+ to start with...

I'd be real curious to find out what any "boutique" alternator really was. Built from new? Or built from re-something parts? I suspect the answer will come back to "pricey" no matter how you do it, if you use new prime parts. There are just limited sources for them, and making your own from scratch would be too intensive in small batches. If "all" you did was change the diode frame, drop out the internal regulator, and add a fan or pulley...that could save a lot of cost, but would leave the original windings, optimal or not.

Anyone know for sure?
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Old 14-03-2015, 08:46   #37
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Re: Most practical way to upgrade Yanmar alternator?

This is how I did mine.
2X Mastervolt ALPHA PRO II MB connected to two 80A Hitachi alternators (Yanmar engine).

Works very well, even with my 1000AH Lifepo4 setup.
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