Hello Roger,

When GM switched to sealed, no-maintenance, lead-acid
batteries, their voltage regulators were changed to regulate
to a lower voltage than they had been using. I believe 14.1
volts is what they use for sealed batteries. This voltage
would probably not harm an AGM, although for "continuous"
use, such as an extended period of motoring, it may
constitute an excessive "float" voltage for an AGM.

Bottom line is that all "old" automotive regulators are not
created equal. Those that were made for the older
(non-sealed) lead-acid batteries are likely to destroy
sealed batteries (whether AGM, Gel, or conventional).

AGMs are not cheap, as you know. Besides, there may be
other, more persuasive reasons for using a "smart" external
regulator.

Be very wary of generalized extensions of automotive
practices and equipment to boating.

Good luck.

Chuck



Larry W4CSC wrote:
"Roger Long" wrote in
:


Anyone out there have any experience or words of wisdom to offer on
removing the internal regulator from a small alternator like a Hitachi
LR135-31 so as hook up an external unit that will properly charge GEL
or AGM batteries?

--

Roger Long



Roger.....

Out in my yard is a 1988 Chevy P-20/Union City Body retired Air Force
stepvan. It's powered with a 6.5L diesel V-8 (AT, PS, PB) with an 80A, GM
alternator with internal regulator, just like every Chevy truck on the
road. There are millions of them.

All Air Force trucks are now equipped with those red AGM batteries to
simplify storage and transport across the planet...charged by those old,
reliable, internally-regulated alternators.

AGM batteries don't require you to hand over $250 to Waste Marine for a
super computer regulator with all the flashing lights. Thousands of them
work for years and years, just fine, across the planet.

Boater nonsense.....BS.....

Why do we beat ourselves trying to see how much we can spend on an
alternator?! It's just a lead acid battery!

The AF records on my van, by the way, show the batteries ran down the
flight line at Pope AFB from 1988 to 2001 for about 8 years between
replacements....

Relax! Just don't mention to any professional boaters in the marina that
you have an internal regulator. Find a fancy one that's tits up and bolt
it into the engine room to fool them.....