You should be able to charge and discharge from the battery at the same
time.
Read up on battery chargers first, the best ones offer big advantages to
extend battery life.

Some will say use caution when running the fuel injection brain with a
charger attached,
(turning on the key while charging).   I have done it but its likely not
recommended.

Doug

----- Original Message -----
From: "Tom Salicos" <Tom@SALICOS.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, January 01, 2006 4:39 PM
Subject: Shore Power Using 12 System ??

There is a second battery in my van's future, but other priorities are
first.  We just took a trip to the Oregon Coast (Nehalem Bay SP) for New
Years Eve.  Plugged into the AC for the first time.  Had a small heater and
a couple of strings of chile pepper lites to run off of it.

The interior lighting, CD player and Sirius receiver are all on the van's 12
volt system and we did not use them.

Question is, what if one continued to use the 12 volt stuff, but ran a
battery charger to the primary (only) battery to keep it from running down?
Any problems or considerations when doing this?

Thanks for ideas.

Tom Salicos
'87 Syncro Westy EG-33