Hackforge is, appropriately, a place where things are hacked. This UPS battery is old enough that it wasn’t holding a charge. Most people would just replace it — but what’s the fun in that?
Our member Dez took up the challenge, prying open the lid on each cell and refilling the battery with distilled water. This is a picture of the battery on the bench being charged with Dez’s variac. So far, it seems to be working!