After doing my occasional Checks on my system.I noticed a weird phenomenon,One of my battery shows a lower voltage that the rest
Three out of the four 8D Deka solar battery(245ah ) reads 12.7 at rest while the other reads 12.56 at rest. While charging all other batteries shows a higher voltage reading than the lower voltage in the bank.
I have accepted it is a failing battery but i have never experienced a situation as such.
There was no sign of failure nor is there no over heating of the failing battery.
Can someone elaborate on this.
What are the specific gravity readings on each cell?
these are agm not flooded
i should add they were lightly used occasionally in the night mostly during the daylight,occasional heavy load. and they are just about below three years.
So that urged me to investigate .
does the manufacturer recommend an EQ or 'refreshing charge' value?
they do have eq charge voltage but nothing on refresh charge
It appears you are running these 4 batteries in series for 48V. It only take one bad cell out of the 24 cell to render a battery low. Just out of curiosity where in the string was the low battery located? Are you measuring the voltage after resting with no charge or loads?
weird it was on the negative side of the string.
I measured both resting and on load .
My minimum measure on the bad battery is 12.54 while on the others 12.69-while resting
on load it will go to 12.26 on the bad one while the others is 12.56 -moderate load(no more than 300w)
heavy it will sag to 12 on the bad one while the other is 12.2 -12.3(800w )