If you got over a year out of the Optima you were doing good anyway.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Geza Polony
Sent: Tuesday, August 07, 2007 6:05 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Deep cycle batteries, voltage regulators, and eating cake

Well, I think I got it. Battery voltage is now up to a level I think will
charge both batteries even under load. Here's what it took:

1. Added 10 AWG wire between vehicle battery and relay. Soldered
connectors.
2. New 10 AWG wire,  relay to aux battery. Soldered connectors.
3. Added 10 AWG wire alternator to starter post.
4. Resoldered OEM alternator connections.
5. Cleaned starter post connectors, added four copper washers (drilled
pennies) for better conductivity.

(Why 10 AWG? I just couldn't find automotive 6 or 8 and needed to get it
done before leaving tomorrow.)

Results:

Vehicle battery, no load, 14.3 vdc
Vehicle battery, full load, 13.66 vdc (AC, fridge, headlights)
Aux battery, no load, 14.2 vdc
Aux battery, fridge, 13.86 vdc (the important number...)
Aux battery, full load, 13.39 vdc.

My conclusion here is that no matter what kind of battery you have, it
isn't
going to do its job right if the alternator/charger circuit wiring isn't
carrying the current needed. I thing I may have destroyed an Optima in the
process, from over a year of inadequate charging.

Many, many thanks to all the professors here at vanagon.edu.

Geza