At 04:52 PM 6/11/98 -0400, Lawrence Johnson wrote:
>> Also, I'd like to know the size wire I should use to connect the auxiliary
>> battery positive to the starter battery battery.<snip>
>
>The wire size depends upon the continuous current that will be drawn (the
>bigger the safer). Add up all of your 12v service requirements and select the
>appropriate wire. Add a fuse to protect your van and family.
>
The size of the wire between the aux and main batteries (through the cutoff
relay) is not based on the load on the aux battery. It's based on the
maximum charging current that you can expect from the alternator. If your
aux battery is drained, you can get a pretty sizeable current through this
wire. The relay is rated at 30 amps I think. Based on the limits of the
relay, 10 or 12 gauge wire should be sufficient. There is a chart of wire
size versus current at
http://www.crutchfield.com/infolib/carlib/S-9CFMCb4UQKa/cable-length-image.html.

-Mark McCulley