Just some relay info for everyone.  I haven't done it yet, but I will as
that part of my camper conversion is ready.  there are heavy duty relays
that are capable of 90+ continuous amps available at West Marine, or just
about any auto, R/V, or marine supply.  I mentioned West Marine because they
usually have them on their shelf for about $30.00.  This type of relay
should solve any type of battery problems out there.

Pete
peterz@gte.net
83.5 vanagon (quasi camper)

>Hi Phillip,
>You asked:
>What would it take to use a higher amp. relay or manual switch?
>How would these be set-up?
>
>My opinion:
>1) A manual batt. switch can give you more flexibility.
>You can switch between different batteries.
>Drawback, one always has to switch back and
>forth, to use the aux. batt., or to charge the aux batt.
>The vanagon "Adventurewagen" has such a system.
>It can be more expensive and time consuming to install.
>
>2) A battery cut-out relay is very simple and relatively
>inexpensive to install.
>I guess Larry Johnson already answered that question.
>I will try to give you some more details.
>It would be helpful, to take a look at a Bentley diagram,
>for a dual batt. setup in a vanagon. In the diagram you can
>see the aux. batt. and the main batt. It actually is a very simple
>diagram. Once you spent some time looking at it, you are ready
>to go to the vanagon and do the installation.
>Things you might need:
>
>1)  A section of # 8 gauge or better # 6 gauge wire, long enough
>     to go from one battery to the other.
>     VW uses a 6.0mm that is about a # 8 gauge wire.
>     The distance between the two batteries is not that much.
>     #8 ga. is good for up to 15 feet and 50 Amp charging.
>     You also need a short section of # 18 gauge wire.
>2)  one 12 volt heavy duty 30 or 40 amp relay.
>3)  one 12 volt 30 amp fuse or optional 12 volt 30 amp circuit breaker.
>4)   at least 4 ring terminals, for the #8 or #6 wire, to connect
>      the wire to the relay and the fuse.
>5)   one batt. ground strap. For the aux. batt.
>6)   one batt.-terminal-connector to use with the # 8 or #6 wire,
>      for securing it to the + terminal on the aux. batt.
>     You also need a connector to fasten the other end of the wire
>      to the + terminal on the main batt.
>7)   Two quick splice connectors for small #18 ga. wire,
>      and two female connectors for # 18 ga wire. The female
>      connectors have to fit the small terminals on the new
>      "Battery-cut-out relay".
>      (you need this to connect the new battery-cutout-relay
>       to terminals 85 and 86 on the existing refrigerator-12 volt-
>       heater-relay)
>      If you look carefully, you will see tiny numbers stamped
>      next to the contacts on the frig. relay.
>      See diagram for camper with 3 way frig in Bentley.
>      These wires are used to trigger the new relay, that is, to
>      make the battery cutout relay go on and off.
>8)  some plastic ties, and electrician's tape and
>     a few sheet-metals screws.
>     The sheet-metal screws are for fastening the new relay in place.
>9)  a couple of rubber grommets, for routing the large wire
>     through sheet metal.
>     My guess, total cost of all this maybe 50 to 70 .
> Optional:
>     A section of flexible conduit to protect the wire when routing under
>     the vanagon. I usually use a piece of clear vinyl hose, to protect the
>     wire from chaffing, where it contacts the body. If the hose is
>     watertight, make sure it will not collect water.
>     Buy some plumber's putty, to seal holes you might have to drill, to
>     route the wire.
>     I wonder what I forgot. Oh... the aux. battery.
>     To put all this stuff together is another post.
>
>      Note: Disclaimer: You should double-check everything
>      with a professional auto electrician. I might have made a mistake.
>      In my own westy, I installed a battery isolator, so I have no
>      long-term experience with the relay setup.
>      But the relay installation is fairly simple and straightforward.
>
>     Also I encourage listmembers to contribute to this collection
>     of items needed or tricks or tips,
>     if you have some experience with dual battery setups.
>
>     Have fun.
>     Harald
>     90 westy.