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Subject:FW: Aux battery & isolator
From:Pollard, Matthew
Date:Tue, 19 Jan 1999 10:36:23 -0800

> "Pollard, Matthew" wrote:
> >
> > thanks for the insight!
> > if my memory serves me right, I am supposed to bend a little copper
> brush
> > that is in the alternator away from it's contact and connect this to a
> > specific terminal on the isolator. I'm thinking this bypasses the
> internal
> > regulator.  Sound reasonable?
> > -Matthew
> >
>
> Nope, you're still using the internal regulator.  BUT... instead of it
> taking its measurement from the alternator output, your're shifting it
> to measure directly at the battery instead.  This automatically
> compensates for the voltage drop across the isolator, which otherwise
> would leave the batteries undercharged.  Note of mild caution: if you
> have anything hooked up to the alternator output lead btw the alternator
> and isolator, there will be two effects, 1) it will see no power unless
> the motor is running, 2) it will see about 3/4 volt more than usual.
>
> NB - unless they've figured out a tricky circuit, you are taking the
> regulator sense voltage from one or the other battery, but not both.  So
> if one is flat but the sense connection is to the other one, it will
> charge slower than you would like.  But it *will* charge.  I'd suggest
> hooking the isolator up so that it senses the house battery, since
> that's the one you're going to be running flat.
>
> Make sense?
>
> david

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