Date:         Sun, 12 Dec 2010 07:56:03 -0700
Reply-To:     Paul Guzyk <paullist08@GUZYK.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Paul Guzyk <paullist08@GUZYK.COM>
Subject:      Re: Weekender Second Battery Question
In-Reply-To:  <1698377177.630293.1292154051241.JavaMail.root@sz0063a.westchester.pa.mail.comcast.net>
Content-Type: text/plain; charset=ISO-8859-1

Yes, the relay should close (join the two batteries) when the engine is on
and battery voltages should be equal since batteries in parallel will
equalize.  The factory relay has no intelligence with respect to battery
voltages.

If you want a smart way to combine your two batteries, use a Surepower 1315
or the http://Bluesea.com/products/7610 product that some have used.

back to stock setup, check the trigger side of the relay, terminals 85 and
86 which energize the relay to connect terminals 30 and 87  (the two
batteries).

You can check the trigger side with a voltmeter, should have 12V when engine
is on.   If not, check the wiring.
Also, when the relay energizes you should hear a small click or you can feel
it if you hold it in your hand while turning key.

If you want to replace the relay, you can find a generic automotive relay
for under $5.00 from your FLAPS or even Radio Shack.

Lots of great general relay info at this site;
http://www.the12volt.com/relays/relays.asp


On Sun, Dec 12, 2010 at 4:40 AM, J Stewart <fonman4277@comcast.net> wrote:

> Good Morning Folks,
> I'm trying to figure out how the second battery set up works in my '85
> Weekender. When I bought it there was no battery under the drivers seat. I
> just installed one, and even though I sold off the fridge unit, I'd like to
> use it to power other things. I got some time to play around with it
> yesterday, and with the engine running, at the relay under the drivers seat,
> one lead was showing 13.94 volts (so that one is coming from the engine
> battery) and the second battery lead was showing 12.51 volts-shouldn't the
> second battery be charging when the engine is running? It doesn't seem that
> it is. Or does it need to drop to a certain level before it starts charging?
> TIA, Jeff
>
>
>
> Jeff Stewart
>