Do you know of any open source-compatible uninterruptible power supplies? I specifically chose this model because APC has (had?) a reputation for being bulletproof.

(My last UPS was also closed source. It liked to beep at odd hours, and sporadically turned itself off. At least the APC doesn't do that, I guess.)

Also, at the end of the day, it's just an overpriced sealed car battery. I wasn't looking for a hobby project, and if I was, this would be low on the list.