The voltage regulator does just that, maintain a fixed voltage. Typical
is ~13.8. The batteries current draw is based on its charge acceptance
which will be a function of state of charge, (SOC), and temperature.
The other limit will be the wiring resistance of the charging path.
Typically, a group 41 will draw about 20 amp/hours from 20% to 80% state
of charge. Then it will taper down to as little as 2 amps.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of Gerald Masar
Sent: Monday, March 27, 2006 1:09 AM
To: vanagon@GERRY.VANAGON.COM
Subject: charge rate at main & aux batt

Just finished installing aux battery in my '90 Westy, using regular
group 41 and the
existing relay system. Everything is up and running fine.
Recent discussions about relays, isolators, separators, over or
under-charging, etc.,
makes me ask this question.:
    Does the voltage regulator sense when the main battery is fully
charged and slow
down the rate or something, and if so, what happens at the aux battery
if it was still
at a lower state of charge?
Hope this makes sense, and thanks.
Jerry in Arizona