Yes, this would work, as it provides the minimum circuit requirement to keep
the aux battery charged. Requires beings always mindful, however. A fire
inside of a vehicle can be a nasty thing. Even melting insulation on some
wires can release toxic stuff into the immediate environment. Use heavy
wire, 8 or 10 guage should do. If you can locate some, use TEFLON coated
wire. A fuse is never a bad idea, but makes the installation more complex.
You may run into trouble determining what amp value fuse to use, however, so
this may be more trouble than it's worth. A discharged battery has a low
resistance, and therefore  presents a high load to a charging source.  A
fuse would likely blow right off if the two batteries are not nearly equal
in their state of charge when they are hooked up.  Be sure to dis-connect
whenever you shut off the engine. For reasons which would require a rather
lengthy explanation, storage batteries left connected this way will
discharge in the absence of some outside potential (charging current from
alternator). When you get the time to do a proper install, use the
"isolator" option, rather than the relay. The isolator consists of nothing
more than a heavy duty diode mounted on a chunk of aluminum which acts as a
heat sink to keep the diode from meltdown.  No mechanical moving parts, or
contacts to get cruddy, and very reliable. Make sure all your connections
are tight.
Chuck N1LNH
----- Original Message -----
From: "Russell, William" <william.russell@UW-INC.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, June 07, 2004 1:38 PM
Subject: Dual-Battery Question

> Well, after a weekend of work, I've managed to get my Optima Yellow top
> installed and the stereo switched over to it.  However, I have not yet
> installed a relay or isolator yet.  What I would like to do, for this trip
> (I leave tomorrow), is employ a manual system.  It would seem to me that
> hooking a wire from the + of the starter batter to the + of the Optima
while
> the car is running would work.  I would like to use something a little
more
> graceful than a jumper cable as I will be living in the van for the next
> week.  If I were to route a wire between the two batter compartments and
use
> alligator clips to connect it, would this be safe?  What gauge of wire
> should I use?  Should it be fused?
>
>
>
> Any help is much appreciated.
>
>
>
> \/\/i!!y
>
> 1980 Westfalia "Jazzy"