Date:         Thu, 30 Mar 2006 21:01:34 -0500
Reply-To:     robert shawn feller <feller@CARBONCOW.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         robert shawn feller <feller@CARBONCOW.COM>
Organization: carboncow
Subject:      electrical experts: voltage drop and the fridge theory.
Content-Type: text/plain; charset="us-ascii"

I am amusing myself since I've been fixing and testing the fridge on the
bench. It's staying cool to 30 degrees on 110v for me. I just bought a new
1000amp hour deep cycle for the new wiring I'm doing in my westy related to
other needs then the fridge.

I figured I would hook it up to the fridge to just see how horrible a job it
does (we all know 12v and the fridge are not the best friends). I should get
a good day out of it based on calculations.

Here is my question:

The voltage at the battery (under load) reads 12.4 volts but at the terminal
it reads 11.5 volts, only 3 feet of wire between the battery and this
terminal! Is the inefficiency of the battery cooling the system do to
improper low gauge wiring?

Seems to me that if there is 7% voltage drop in such a short run the wiring
gauge for the heating element and the wires to the battery could be
improperly rated. This would then affect amperage and thus the final wattage
(which is supposed to be the same as the 110v) is never achieved. I would
assume those of you keeping the battery under the seat and running more
length of wire then I would have slightly more drop.

 If I recall from my boat wiring days a 3% drop is the recommended goal for
any length of run from the governing body for boat builders but as high as
9% for least acceptable.

Any thoughts.or do  I not know what I'm talking about!

Shawn