I have an old APC Back-UPS 200 I'm hoping to use for my PC.
Connected to power it works fine.
When unplugged it emits a "i'm on battery power" constantant tone.
The 2 plugs on the back are not receiving any power though.
I opened it up and checked how much power was going in. About 11V for the 12V battery.
The fuse was also fine when checked.
There is a capacitor I can see from the side but it doesn't look bulging.
Is there anything else which might have failed that I can easily replace?
Thank you for your help.
Best Answer
As David mentioned, the battery is almost certainly dead if this is an older UPS, and this is confirmed by an 11v measurement when you know the battery should be fully charged ( when it should be 13-13.8v ). More importantly, a 200 VA UPS is so weak as to be useless. Modern PCs have 350-500 watt power supplies ( more for extreme rigs ), so you need at least a 350-500 VA UPS, especially if you want to also have the monitor plugged in ( to a battery backed outlet ). I have had a 1000 VA unit ( extra capacity -> more runtime ) for 14 years and have had to replace the dual batteries every 2-3 years.