APC Smart-UPS Self Test is passed even if the battery is damaged

[Anonymous user]

I have this APC Smart-UPS RT 2000VA with external battery pack for more than 7 years.

When I try self test option, it gives me "Passed" result, and shows 100% battery capacity.

(Sometimes battery capacity will suddenly drop up to 50%)

But when I unplug the main power, the UPS is turned off in 2 minutes showing battery low indicator.

If the battery is bad, why doesn't it show me warning ?  How can I know if this is the issue of UPS or Battery ?

[BillP · Accepted solution]

Hi Yesudasan

The Battery Packs typically have a 3-5 year life span, It is likely that at this age your batteries have a higher internal resistance, so the short time they are used during a self test is fine, but they are struggling to perform when the UPS is on battery for longer durations.

Regards

Matt