Low morning Batt. voltage

wespo

Re: Low morning Batt. voltage

I have been using the system as a "whole" with the bad battery...is it better to take out that bad string and run on just 1 string until I find replacements, or can I keep both strings intact and continue to get use out of them all??

Thanks.
Bill

BB.

Re: Low morning Batt. voltage

Depending on what the failure is... If it is simply "low capacity" then you can probably leave them in. May not matter much if the capacity is 1/2 or less of the other string.

If the failure is an open cell--it does not matter (little energy available). A partially open cell may overheat during charging/discharging and force you to remove the bad battery.

If the failure is a shorted cell--then you need to pull the bad battery. The shorted cell will draw the rest of the parallel batteries down (during charging and during use). Also, shorted cells may overheat and cause further problems.

-Bill

Photowhit

Re: Low morning Batt. voltage

I would lean the other way, remove the bad string. as they are connected the good string will always try to "bring up" the bad string hence bringing down it's capacity.

Their might be some over charging going on as well since the voltage reading will be measure based on the weak string.

Either situation will be hurting your good string. I'd remove the string then let it cycle a few days and see where your at. I'd guess your morning voltage will be up a bit...

wespo

Re: Low morning Batt. voltage

As a follow-up:

I removed the bad string.

I charged the "good" string to what seemed to be a full charge...14.1 volts each.

That string held through the night for about 10 days...with morning voltages dropping each succesive day.

I measured the voltages this morning (21 days out), as the inverter low battery disconnected, and found 1 of the remaining 2 batteries was low at 10.15V, the other battery read 12.45V.

I am assuming there is some sulfation going on here. I plan to remove the welded covers. Anything specific I should be looking for in the cells? I do have a hyrdometer and plan to test the electrolyte.

An interesting note is that 1 of the "bad" string batteries left sitting out has increased it's voltage to 11.42V. Any chance this is salvageable for light duty use (small fountain pumps, etc.)? I have a small 20W (12V) panel I can directly connect to it.

Bill

westbranch

Re: Low morning Batt. voltage

look here for some different views on battery failure.

http://home.comcast.net/~ddenhardt201263/desulfator/lowpower.htm

HTH
Eric