Date:         Wed, 5 Feb 1997 18:31:10 +0200
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "Richard Lumb" <richard.lumb@dlr.de>
Subject:      Re: Electric confusion


Jim Maginel wrote:

> Since the subject of auxillary batteries has come up, I also would like
> advice on 1)how to best use the auxillary in my 85 "weekender", as it
> appears that all it is hooked to is the extra ciglighter for the removable
> frig, which I do not intend to use.  I feel that it would be beneficial to
> use one battery for ignition purposes only, and run everything else off the
> second battery? or should I just wire them together, and if so, what is the
> purpose of a "relay"?

I went through this process not long after buying my '86 Westy 
Multivan (same as Weekender in USA?).  One particularly nasty night 
in Scotland led to the discovery that everything except one aux 
socket was on the 'main' starter battery: interior flourescent 
strips, petrol/gasoline heater, the lot.  Next morning - no start and 
a battery swap required :-(. I subsequently rewired the 'house' 
electrics (fridge, strip lights, heater, fresh water pump etc) onto 
the aux battery via an additional fuse box put under the driver's 
seat.  The 'auto' electrics I left well alone on the prime battery, 
in the interest of simplicity!

You may want to leave it at that - but be aware that repeated deep 
discharge (e.g 4hrs plus of fridge use) of a standard starter battery 
sends it to a very early grave: better to use a marine or leisure 
battery specifically designed for repeated deep discharging.  I 
couldn't find a deep cycle battery that would fit in the box under 
the seat so ended up putting two in parallel under the rear-facing 
seat (180 ampere-hour capacity) and keeping the original aux battery 
where it was.  _Another_  one of those relays required! Now  there's 
always a fully charged battery available even if the fridge gets left 
on all night with the headlights!

All that the relay does is isolate the batteries from each other
when they are not being charged from the alternator.  They charge
together but flattening one battery does not take the other(s) with
it.  Useful!

Since the space under the rear-facing seat was being eaten up anyway, 
I've also added a mains hook up with RCD fusebox and battery 
charger - I'm  _really_  paranoid about running out of sparks.  

BTW, anyone know the cost of solar panels? :-)

HTH
Regards,
Rich Lumb
'86 Westy