UPS that someone gave me because it didn’t work:
Minus its original batteries, apparently slightly past their prime, which I had to pry out of the case by levering with a big screwdriver:
Plus three-year-old unused batteries from the campus fire chief:
Equals I can play my “new” Hammond organ, which is temporarily in storage where there’s no electricity:
When the UPS is off and there is no utility power, it is possible to cold start the UPS to power the loads from the UPS’s battery.
Note: Cold start is not a normal condition.
Press and hold the on/test button until the UPS begins beeping.
Release the on/test button during the beeping to start the UPS.
Runtime with a 15W wall wart plugged in was about an hour. Runtime with the Hammond plugged in (after fully recharging) was about three minutes. I guess free batteries are worth what you pay for them . . . but I do now know that the UPS works and is worth replacing the batteries.