Date:         Wed, 7 Oct 1998 22:16:22 -0700
Reply-To:     "Philip Hanson (Volt Computer)" <a-phanso@MICROSOFT.COM>
Sender:       Vanagon Mailing List <Vanagon@vanagon.com>
From:         "Philip Hanson (Volt Computer)" <a-phanso@MICROSOFT.COM>
Subject:      Re: Adding the second battery to the early vanagon ('80)
Comments: To: Vanagon@VANAGON.COM

Well sure.  I was thinking of putting an aux battery under the seat.  And
just use an off the shelf isolator.  Think that would work?  Just so it
works the toaster right.

-----Original Message-----
From: David Katsuki [mailto:dkatsuki@WORLD.STD.COM]
Sent: Wednesday, October 07, 1998 8:59 PM
To: Vanagon@VANAGON.COM
Subject: Re: Adding the second battery to the early vanagon ('80)


The problem with just connecting the second battery in parallel is that
they both discharge at the same rate and at the same time.   A primary
reason for wanting a second battery is to avoid the embarrassment of
needing a jump start after using your 12v camping appliances too much (12v
blender for the fish, 12v dishwasher, etc.)
When the aux battery is hooked up either with a diode isolator, or with a
relay isolator, the two batteries can discharge (or not) independently but
are both charged from the alternator when it is making whizzies.    Late
model campers (at least) have a relay under the driver's seat that prevents
the fridge from running off 12v unless the alternator is making the
previously mentioned wizzies (a technical term), and so the easy way to
hook up an aux battery when the isolation relay is there, is simply to put
it in parallel with the fridge.   I actually connected mine through a 30A
fuse to avoid even more embarrassing fires.

Dave
87 Wolfsburg
90 Westfalia
<snip>