Yes, they are annoying. And you don't always know when your battery is reaching end of life. After having to take a last minute flight to fix a problem caused

Yes, they are annoying. And you don't always know when your battery is reaching end of life. After having to take a last minute flight to fix a problem caused by a brief power outage I decided to mod the UPS to run off of deep cycle marine batteries. This is a 1500W APC unit. I picked up a couple of the biggest batteries they had at walmart, cut a hole in the side of the UPS, soldered in some 2 AWG wire, and connected the batteries in series with some ring terminals. The batteries charge up fine and they have gotten the servers through several multi-hour outages. It's coming up on five years now and they don't have the capacity that they used to. I'll probably replace them soon.