I have an older APC UPC, and the battery appears to be dead. It appears to be a small, lead-acid 12 battery – is it possible to revive the battery?
It's certainly not worth it to replace it – a new battery, even a no-name, is about $50 shipped – a whole new UPS, with similar specs, is only $65.
Best Answer
The Battery University site is a good resource for various batteries.
How to restore and prolong lead-acid batteries and Charging the lead-acid battery.
Another reference -- Alton's Battery Page.
But, I'd just replace them (like I have once with my APC).
A Good reference page at BU.