[RE-wrenches] Trace inverters undercharging batteries.

[Mick Abraham]

Hello, Jesse~

It's possible that the Trace inverters are not set up correctly or
malfunctioning...or improperly sized relative to the battery bank, but
perhaps there are other red flags which must be addressed. One can read the
amperage and voltage to which the battery is subjected during recharge and
compare those to rated specifications plus good system design guidelines,
but only with meters that can get that done. You probably carry portable
metering but something built in is better because you can't be there all the
time.

Please advise if there is any DC battery monitor in the system. This would
involve a brass shunt for the high current plus an amp hour meter to track
the battery current in both directions as it fluctuates over time.
Tri-Metric is one popular brand for that type monitor. Without an amp-hour
meter, system diagnostics are difficult at  best. Voltmeter functions are
also needed but built into a meter such as Tri-Metric or often present
elsewhere in the system.

Frozen batteries can only result from low state of charge combined with low
temperature, and when they freeze up things inside can break and degrade. If
the system owner thawed out the ice, poured out the watery electrolyte, then
replaced that with standard 1290 specific gravity battery acid...that may
have provided short term symptom improvement while hastening overall battery
destruction. When recharge followed the electrolyte addition, the acid would
become even heavier (more concentrated), and the problem with that is a
heightened chemical attack upon the structures inside.

Regardless of what you learn about how well the inverters are working, this
end user should brace up either for battery replacement or for continued
high reliance on generator running time. If a battery replacement effort
goes forward, basic DC metering should also be factored in. This type of
advice is probably the last thing the owner wants to hear, because battery
replacements are costly and traumatic. 'Tis the season...

Jolliness,

Mick Abraham, Proprietor
www.abrahamsolar.com

Voice: 970-731-4675


On Tue, Dec 28, 2010 at 11:04 AM, Jesse Dahl <dahlsolar at gmail.com> wrote:

> Wrenches,
>
> I have been in contact with a person living off-grid in Northern MN.  She
> had some problems with her system and called me.  I teach a solar class at a
> local community college and have been helping her in my free time (free of
> course!).
>
> Some of her batteries froze last winter and she said she dumped out the
> electrolyte and put new in........ (6 V Rolls)
>
> Her main concern was the batteries never fully charging.  She has a very
> nice Kohler gen, but from what I have been told, the Trace inverters may be
> part of the problem with the batteries undercharging.  I have limited
> experience with off grid applications and any help would be greatly
> appreciated.
>
> Jesse
>
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