Can an Internally Regulated Alternator be Changed to External Regulation ?

[freshalaska]

I have a 62 hp Yanmar engine with I think a 12 volt 50 amp internally regulated alternator. I'd like to be able run the engine and to manually adjust the voltage so I can fast charge my batteries and equalize them from time to time. My battery bank will be about 880 amp hour capacity, and I also have a few solar panels and a wind generator and a 2.8k genset, on the boat.
Guess the question is can I convert the internally regulated alternator to one that is externally regulated? Mark

[Pblais]

Guess the question is can I convert the internally regulated alternator to one that is externally regulated?

You could have a shop do this easy enough but I'm not sure a 50 amp alternator will matter much. Your 62 HP engine could handle a much bigger one and then you might be able to increase the real output. I would just get a bigger alternator and maybe save the old one as a spare. A spare alternator isn't a bad idea. You'll then be able to get a decent regualtor that really will cost more than a new alternator and 50 amps is pretty small given you'll never get 50 amps out of it. I woul also add a combiner to isolate the starting battery yet keep it topped up.

[surfmachine]

Sure, I have converted 2 such alternators, you will need an expensive external regulator, the advantage being that they are 3 stage regulators and will charge your batteries quicker. Just disconnect the internal reg and run the field wire outside to your external regulator input.

Lots of detailed descriptions of how to do it, even made mine electrically isolated for my alloy yacht.

Keith

[Nemo55]

50 amp is pretty meager,,i am used to dealing with Alternators with Amperage over 140 ,,,and then there is always room for more.
Just go bigger,,the load on your engine will only change with the amount drawn, so it wont affect much until you need it.

[djmarchand]

If the alternator is the 55 amp Hitachi then it probably isn't worth converting it. There are several suppliers of high output alternators: Balmar, Ample Power, Hehr, Powerline, etc. These have heavier windings and better cooling systems than the Hitachi.

But don't go more than about 100 amps on one belt. Any more will wear your belt out rapidly.

David

[bobconnie]

You can always get a GM ambulance alternator, and have it changed to adjustable out put ! it is a bunch cheaper if bought used, and puts 100+ for your chargeing needs ! Just a thought from an old cheap sailor

[freshalaska]

Thanks Kieth, how expensive an external alternator cost you talking, where do I buy them. Come to think of it I think I've got a 80 watt alternator with the engine also and that should be the on I'd like to convert it so I can control the voltage and amperes out put. These internally regulated alternators aren't set up for charging house batteries very well. Mark

[Marner]

Cranking up the voltage manually is not a good idea, as I have found out.
Been there done that

The output voltage is also a function of the alternator temperature, and its regulator will reduce the voltage to protect the alternator windings. Trying to get 50 amps out of a 50-amp alternator continuously in the heated confines of an engine compartment, by overriding the regulator's settings, will soon burn out the alternator.

Marner
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Cruising Cape Breton | Introduction

[surfmachine]

$280 usd for a balmar external reg from westmarine

BALMAR ARS-5 12 Volt Regulator at West Marine

You will have to rev the engine to get any where near the max output, the value of an external reg is that they have the 3 stage charging.
Keith.

[Kettlewell]

Since you have solar panels and the gen set you could easily just upgrade to around a 100-amp alternator to get a bit more oomph when the engine is running, but I would look at using your generator for battery charging when at anchor. I've had good results with standard Delco 12SI alternators (available worldwide and parts everywhere) rated at around 100 amps. Just make sure you have the right regulator--they can come with all sorts--ones are available with set points at 14.4 or higher volts. Leece Neville makes some better alternators that don't cost as much as the big-name "marine" ones, but still feature quality construction. MaineSail has a great discussion about whether or not you really need an external regulator--a lot of folks don't.

[freshalaska]

How do I find the discussion about external regulators on MaineSail?
Is this a web site or forum or magazine. Did an internet search and can't find it. Great help everyone!

[Kettlewell]

Musings Regarding External Regulation

[freshalaska]

Really good article about smart and dumb regulators.
So how does a person equalize a deep cycle wet cell large battery bank?

[Stu Jackson]

There's also this:

Converting An Alternator To External Regulation - SailboatOwners.com

Don't buy a Balmar alternator. Leece Neville makes 'em for Balmar and can get one for you at a fraction, literally, of the Balmar price.