When the lights went out today I noticed my UPS battery didn't work. I checked the monitor and this is what I see:
As you can see it says the battery has 90% but when I pull the plug, it doesn't work.
Is there a way I can fix this or find out if the problem is battery or UPS?
This is my UPS model I bought this FEB 2012, so it's about 1yr8mo. I only noticed the problem now because it's only now there's been power interruption.