<VV> Adding a backup electrical system

[Chris C, Warwick RI]

Tinkering with purchasing a Greenbrier.

When I deck it out with modern electronics.

Radio/portable DVD PLAYER, maybe a small plug in beverage cooler.  I want 
that system isolated from the battery for starting the van.  This way if we 
are at a cruise and the chillies want to have friends in to watch a movie 
or listen to the radio, I won't run the battery dead.

Was thinking of wiring this connection into the charging circuit, so it 
will charge when the van is running, but won't drain the battery during 
normal use.  Is this feasible, has anybody done it.

Thanks to all.

No I have not got the van...yet.  Still trying to sell the 65 pg sedan.