The voltage dropping Isolator is not a Separator. Different products
entirely, though the same company makes both. The 1315 Separator
connects full voltage through it.

The voltage loss problem you refer to does not apply to all isolator
installations either. If you buy the version built for our Bosch
alternators it tells how to modify the voltage regulator to overcome
this drop. I don't approve of the isolators for this and other reasons
but lots of people use them with good results.

The battery switch method works fine for lots of people as well. It is
just a more cumbersome way to do it and pointless for most Westy aux
battery needs. The Separator is the most graceful approach, with a high
current relay a close second at a lower cost.

The marine battery switch setup you describe is a far more intrusive way
to do things. Even harder on a 1986+ model.

Mark

Robert Keezer wrote:

> Ron,
>
>
> I have done several dual battery systems for hire
> and the set-up of choice is a optima yellow or
> blue-top for auxilliary with a 4-way marine type
> high-amperage switch.
>
> I was heavily influence by a very readable book
> called " Living on 12 Volts with ample power".
>
> The author reccommends the high-amperage switch
> over the isolator, claiming the isolator lowers
> the charging voltage by amost 1 Volt.
>
> Using a switch offers more options. You can
> charge both batteries in tandem, or each
> individually.
> The swich also allows you to switch off all power
> to your car when performing work, or during
> storage, etc.
>
> ......................