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Subject:Did I hurt my Aux Battery?
From:neil N
Date:Wed, 3 Sep 2008 21:35:55 -0700

Hi all.

2-3 years ago, I installed a smallish, sealed, 40-ish amp house
battery in my Westy. At time of purchase, I didn't note the battery
type. (deep cycle or AGM). I *think* it's a deep cycle, but am not
certain.

My new "intelligent" battery charger:   http://tinyurl.com/6jryzn
tops up the battery quite quickly at the 8 amp/deep cycle setting.
Coupled with the fact that the incandescant interior light and
portable DVD player drained it down to ~ 20% fairly quickly, I thought
it might only be "surface" charging. I charged it a second time. It
still charged back up quickly. (1/2 hour -  45 minutes).

Is the fast charging a bad sign? I hope that using a standard charger
or vehicles alternator all this time, hasn't damaged the batteries
ability to hold a charge.

Would it help the battery to hold a charge longer if I drain it down a
few more times and do a slow 2 amp charge?

Is there an easy way to tell if the battery is deep cycle or AGM?
(that way I could knowingly use the right setting)

FWIW, after the second charge, running ONLY the DVD player for 2
hours, drained it down to 60% or 12.3 volts (says the charger). I
don't know how many amps the DVD player draws. Nothing in the manual
or online. AC charger says 1.3 amps on it. Maybe I could measure the
draw with my VOM.

Thanks for any help,

Neil.

--
Neil Nicholson '81 JettaWesty "Jaco
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
http://web.mac.com/tubaneil
http://tubaneil.googlepages.com/