Date:         Tue, 16 Jul 2019 07:49:57 -0400
Reply-To:     The Bus Depot <vanagon@BUSDEPOT.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         The Bus Depot <vanagon@BUSDEPOT.COM>
Subject:      Re: Battery question
In-Reply-To:  <4E013345-1A30-43FD-A858-E6FF80EF742E@comcast.net>
Content-Type: text/plain; charset="us-ascii"

> After a excellent camp out at West River Westies this weekend we were
> just about the last foks to leave.  When I went to start the van it was
dead.
> I have a house battery with the GW kit.
> Why would my starter battery run down with the use of the house
> battery?  I don't think they are connected.  Then again both do charge
from
> the alternator.

The GW kit is described as using an isolator. If the diodes in an isolator
fail, it will typically fail in the "closed" position, joining the two
batteries even while the key is off, so unbeknownst to you your starting
battery is draining as you camp. I learned this the hard way years ago in a
similar situation to yours, except in my case we were camped remotely and
both batteries were completely dead.

By comparison, relay based systems (like ours - http://www.busdepot.com/1738
- and like the one Westfalia used themselves in dual battery equipped
campers) will fail in the "open" position, so in the event of a failure your
camping battery won't recharge but your starting battery will not be
affected.

Ron Salmon
The Bus Depot, Inc.
www.busdepot.com