I had the same thing happen to me with my aux battery.  I tested the
aux battery voltage with my hand held meter and discovered that the
aux gauge I had installed had "deteriorated" somehow and was now off
by -0.5 volts.  So now when I see the gauge reading (say) 12.5 I
remind myself that is actually 13.0 volts.

- Laurence

----------------------------------------
Laurence Smith
Hamilton, Ontario, Canada
90 Westy (fanumbos)
87 GL / 91 Subie 2.2
----------------------------------------

> -----Original Message-----
> From: Vanagon Mailing List
> [mailto:vanagon@GERRY.VANAGON.COM]On Behalf
> Of Josh Greenberg
> Sent: Tuesday, September 09, 2003 1:11 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Auxiliary Battery Issue
>
>
> Volks,
>
> About six months ago, I installed an auxiliary battery into
> my Westy.  Since the rely was already present it was a
> relatively painless job and the installation went smoothly.
>  I didn't have the money to purchase a deep cycle Optima
> battery and decided to use a standard Diehard instead.
> Since installation, I've worn down and recharged the
> Diehard numerous times.  I understand that regular
> automotive batteries aren't meant for that type of use.  I
> also directly wired in a voltage meter so I can monitor the
> amount of juice left in my auxiliary battery.  All that
> being said, here is a description of the issue I am experiencing.
>
> When I power up the engine the voltage meter DOES read
> higher.  However, now it only reads marginally higher.  For
> example, the voltage meter might go from 12.8 to 13.0.  It
> used to read significantly higher, say from 12.8 to 13.5.
> At first, I thought the rely might be fried.  Yet, it does
> seems as though the rely is working.  I checked all of the
> wiring and it does look intact.  Another piece of
> information that my help is right around the time all this
> began, I had entered my Westy to find that my auxiliary
> battery had been completely drained.  I assumed I left the
> stereo on accidentally, which is also directly wired to the
> auxiliary battery, and I recharged the battery using an AC
> battery charging system.
>
> Could my alternator be going bad and not outputting enough
> juice?  Has my auxiliary battery been effected by the
> constant charging and fully draining process.  Could the
> rely be fried?  Or, does this behavior sound perfectly normal?
>
> Thanks In Advance,
> Josh