Date:         Wed, 3 Nov 1999 14:01:00 -0800
Reply-To:     harald_nancy <harald_nancy@EARTHLINK.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         harald_nancy <harald_nancy@EARTHLINK.NET>
Subject:      Re: Is battery isolator better than a relay?
Content-Type: text/plain; charset=ISO-8859-1

Relays, isolators, switches... sounds like fun :)

To add to the debate, some real life experience with the
battery isolator.
First the installation is somewhat more tricky, but not that
difficult. The alteration to the alternator regulator is very
simple. Alternator need not be removed. Just unscrew the
regulator ( that black thing with the little round disc) and
take it out. ( be careful with the brushes)
Bend over the metal tab that contacts
inside the alt. ( bend it all the way up)
and solder a # 14 wire to it.
Push the contact prong inside the alt. a bit more in, to
make sure it won't make contact. Reinstall regulator.
That wire goes to the R terminal on the isolator.
I think that shouldn't discourage anyone from using
the isolator.
The other thing is to remove all the red wires, also the
air cond. ones from the alternator B+.  Then extend them and
connect them to the nr. 1 terminal on the isolator.
You should have only one fat wire go from the alternator B+
to the isolator A terminal. Really no big deal.
I think that is where some people make a mistake.

My isolator has lived in the engine compartment for 7+
years now and is doing just fine.
( in the corner by the right rear tail light)
One is supposed to keep them away from exhaust
manifolds, mufflers etc. Intense heat can damage the
isolator of course, like everything else,
but the engine compartment is ok ( my experience).

In everyday use I found the isolator to be very reliable.
Batteries charge well and both batts. are always in top
condition. Very important, since mine is an automatic. vang.
Batteries last a long time with this setup. The orig Varta
starting batt. lasted 8 years, spending most of its life with
the isolator. Never got stuck with a dead battery.
Some thoughts:
I never use trickle chargers when camping.
Extension cords take up too much space on long trips
anyway .
If you camp where you can plug into the grid, you might
as well use 110 volt heaters, lights and such,
and not bother with any deep cycle battery installation.
So if you want a true self-contained system, an efficient
12 volt charging setup for both batteries is important.
I think the batt. isolator fits that bill, at least for
hands-off operation.
Why do batt. isolators get such a bad rap on this list?
Truly I don't know. Perhaps, because they cost more,
but they are not that expensive, and last a long time.
Or maybe because one has to run a wire from the isolator
to the aux. battery. Some listmembers had trouble installing
isolators, and couldn't get them to work properly.
Or because of the voltage drop.
On my vanagon, the voltage meter on the dash shows
13.8+ volts at startup, and then after some time, it goes
down to somewhere around 13.2 volts.

If you have the 90 A bosch alt. in good condition,
the model 1202 R from Sure Power will work very well.
That's the only isolator that I would use on a vanagon.
Harald Rust
90 westfalia