Date:         Fri, 21 Dec 2001 08:37:38 -0500
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: A twist on dual-battery configurations
Comments: To: ThingGuy@AOL.COM
In-Reply-To:  <46.1fb52273.295443f9@aol.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 02:51 AM 12/21/2001, Steve Lashley wrote:
>In a message dated 12/20/01 7:40:36 PM, dbeierl@ATTGLOBAL.NET writes:
>
><< If the aux battery were totally dead or shorted, as soon as you
> >turned on the ignition, it would try to pull everything from the starting
> >battery all at once, and the relay would let it. The result of that sudden
> >massive current transfer could be a fire or explosion.  No, it is not a huge
> >risk, but it is a real one, just as there is that potential when you try to
> >>

Of course I didn't write that, Ron Salmon did.   But I'm sure he knows that
the connection happens when the alternator starts charging, not when the
key goes on.


>The original Westfalia setup only draws current from the alternator and then
>only when that current is available.

Well...under the right (wrong) circumstances it could possibly draw from
the starting battery -- if the aux battery were so far down that the
alternator couldn't pull the system up above 12.6 volts or so.  It wouldn't
be a lot, or for long, though -- unless there really were a massive short
(not just one cell) in which case you'd either have the popping fuse -- or
the burning harness.

david

--
David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"