If an on board or solar charger is to be added then it makes sense to use
one of the automatic battery combiners so that these chargers can also
support the chassis battery. A permanently installed charger should designed
and UL listed for the RV application.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
mark drillock
Sent: Wednesday, March 13, 2013 6:41 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Alliance Deep Cycle? (Grp. 27) Wire To Alternator?

Yep, if triggered only when the engine is running then the draw of the
solenoid coil is of no major concern. Some people try to use a selector
switch to let either the alternator blue wire control it or select battery
voltage to force it to combine during engine off charging, whether by
trickle charger or solar. In both cases the draw of the solenoid can waste
much of the charging current. Also some dual battery automatic combiner
products use solenoid relays and those need to be chosen carefully if solar
or trickle charging is planned.

If using the blue wire to control it on a Westy and the 3 way Dometic is
still present I would consider use of the output of the fridge relay to also
drive the solenoid coil and reduce the load on the alternator blue wire.

Mark

Don Hundt wrote:
> If the solenoid is triggered by the blue alternator wire, it would
> only be activated while the engine is on. If you install the solar
> panel wiring downstream from the solenoid it shouldn't affect it .
> Don
>