I have an APC SmartUPS 1000 for my servers.
It was good for over 2 years, its capacity is always 5/5. One day I saw a red light illuminated. I searched for the reference it is either "Replace" Battery" or "Battery Disconnected". If that was battery disconnected, there should be a beep sound with it and it didn't beep, so I assume it is battery replace.
Battery should hold for 5 years from what I heard. This building has suffered electricity suspension and the server didn't shutdown in time so the battery is completely used once.
So I was curious what is going on, because the load is 1/5 and the capacity is 5/5. So I think the battery is still good until I pressed the "Self Test" button. Then the capacity suddenly dropped to 2/5 and the load is dropped to 0/5. And then I pressed it again, now the capacity is dropped to 1/5.
Why does it drop this much? Is the battery damaged or it is time to replace (i.e. The APC UPS is telling the truth)? Or, the APC UPS has a problem? The APC UPS is quite old though, over 7 years.