it is 12V SLA battery 7A from UPS of computer
I know i should give it for recycle.
the battery is showing 8.5V
can we recondition it so we can work for few days more.
overcharging again or something like that.
I have heard about conditioning or reconditioning of battery.
So it is possible in my case
SLA's lose one cell, normally. You can open the cover and identify/isolate the dead cell/s by a jumper and use the battery with reduced voltage. Every cell is worth 2V.
A normal 1/10C charge will let you know if it was a waste of time!
Try charging it, than discharging and re-charging it a few times.
Sometimes that will help.
Discharge it at a Fairly High Rate, but try not to discharge below 10.5 volts.
And do not exceed 14.5 volts on the charge.
If it Won't charge up properly or if it Won't Dischage at a Fairly High Current, It could have a Bad Cell. There is really No Cure for that.