Date:         Tue, 20 Jun 1995 17:05:22 -0400
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         drew@interport.net (Derek Drew)
Subject:      Electrical Leak Problem Solved

Thanks to all who helped on my quest to determine why my battery was
draining dead all the time. 

This is a report on why and it is somewhat embarassing as the problem was
fairly simple.

Anyway, the evidence was that three batteries in a row were going dead. The
last battery was brand new a giant group 27 Exide Marine deep cycle battery
I put behind the battery seat.

This battery would go dead over about a three hour period while I was
camping in the woods with a set of lights on. It would also go dead once I
left the van parked for a week.

When I tested the voltage, it showed a healthy 12.65 even after the surface
charge had been removed. But a three amp load (the Westy reading light
strip) would drain the battery down to 11.90 volts (meaning, dead) after the
three hours I mentioned. This would be impossible unless there were also
another big drain, like a 30 amp drain into the starter, as someone
helpfully suggested.

The battery would run down when I left it with the battery ground strap
connected. When I would leave the battery disconnected from the ground strap
for a week, it would still show the healthy 12.65 volts so it seemed obvious
that there was an electrical leak in my vehicle. 

I decided that the only way to accurately trace the leak would be to have an
ammeter and see how many amps were flowing through the leak. I purchased
Radio Shack's current cheapest multimeter last Friday, the automotive model
that goes for $49. It has a DC ammeter rated up to 10 amps.

I connected the thing and it showed only a 1/2 amp draw. This was because my
refrigerator was going on a hot day, and its rear fans were going (I say
fans, with a plural, cause I added a second fan from radio shack in the back
plus another fan inside the fridge; these come on when the black cooling
fins behind the refrigerator reach 125 degees F.)

Anyway, without these fans, and with the radios off, the amp load was less
then 0.09 amps so this suggested that the leak was either intermittant or
that the battery itself was at fault. 

I then decided to switch from the voltage method of determining battery
condition to the messy hydrometer method of drawing the battery fluid up
into a beeker thing. The second cell I tested showed no specific gravity at
all. Thus, the brand new battery was defective. I returned the battery to an
Exide dealer and got a brand new one for free. 

Problem solved.

It is *really* cool to have a digital ammeter, by the way. I want one in the
dash to measure the amps at each battery, and coming out of the alternator.

VDO has a really nice looking Night Design model, but it is not digital.
___________________________________
Derek Drew
drew@interport.net (main address for e-mail)
derekdrew@aol.com (alternate/backup address, checked infrequently)