G'day Justin,

Sounds like fun!

During storage, was there a regulator between the 33W panel and the
batteries?

Symptoms you see are consistent with electrolyte loss or plate damage
due to overcharging, overtemperature in storage, charging below
freezing, or structural fault due to impact or extreme vibration.

Voltages you see are consistent with one or two cells failed, rest
of the cells working.

I've seen these symptoms many times, and I've found it impractical to
root cause unless I've a good history to draw on.

I've tried adding small amounts of water to cells to try to restore
the loss, but it rarely makes a difference; and it can take a long
time for the water to integrate into the electrolyte.  Also, they
can look dry because the electrolyte is stowed away in the glass mat.

These batteries will be damaged by overcharge if connected directly to
a 12V vehicle supply; because without a charge controller they will be
at a voltage higher than safe float.  So if you fed them while driving
out there ... don't do it next time.

Alice Springs forecast minimum tonight is zero degrees centigrade, so
don't charge if the batteries have cooled below zero.  Add insulation
for overnight.

I'd get rid of them; in Australia they have recycle value.  For your
next set of batteries, I've two suggestions;

1.  stick with AGM VRLA and make sure you have a regulator with
temperature compensation,

2.  switch to a LiFePO4 pack with embedded battery management system.

I'm trying out a Sentry Lithium SL12V40 (no longer listed) from Sealed
Performance Batteries in Brisbane.  You'll need a smaller battery
because they can deeply discharge.  But their operating temperature
limits are severe, read the datasheet.  Cost is higher, but if you
calculate the usable capacity and extra features it is easy to
justify.  Mine doesn't have a Bluetooth device, but the later models
do; I'm not too happy about that, the last thing I want is a remote
hackable battery.

--=20
James Cameron
http://quozl.netrek.org/
--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.