Yeah, both of my UPSes have reached end of life. The slightest flickering as wind messes with the power lines is enough to knock out anything plugged into them. Time to figure out how to replace the batteries, assuming these things are even user-serviceable.

@KinkyKobolds if it would be at all helpful, if you'll post make/model I can look for the manual and for replacement batteries.

@KinkyKobolds that’s some very severe battery degradation if they won’t switch over even for a few seconds - did you ever test them with your current power draw? Are you sure the inverters aren’t just being overloaded? (Before you invest in a new battery)

@Mudlark
I don't believe I'm running them anywhere near their limited theoretical load, but I was very lazy about testing them. I'll need to find the manual and give it a try.