Battery Backup UPS size?

[meg]

My study electrical outlets trip when I turn on the light in the adjacent closet so I have bought a APC Back-UPS ES750, which is working nicely for one desktop. Can I put another desktop on it? How do I figure that out?

[RickyTick]

You should be able to connect another pc to it. The purpose of the UPS is to give you enough battery time to properly save your work and shut your system down. It's not really designed to be like a generator and provide electrical power for you to continue working like normal.

I'd be a lot more concerned about tripping breakers when a light is turned on in the closet. ;)