Help with battery backup for my APC 650

[mumblehere]

bit off topic, yet need advice regarding battery backup

having a p4 basic system with 5.1 speakers (no gfx card, 1 hdd)

im having apc 650. need backup of at least 5 hours on approx 50% load on above system.
which battery shall i go for b/w 5-8k, model?
specifically, any prob with apc ups with battery?

(not planning to go with smartups, hence it ll b too much for me)

[desiibond]

hmm. you certainly need an external battery to get 5hr backup from UPS and since APC 650W can't use external battery, you need to start looking at a different model.
something like this:

APC Smart-UPS RT 1000VA 230V No Batteries + SURT48XLBP Battery Unit.

but this certainly will cost lot lot more than your budget. check with local solutions if you can get a 2kVA or higher model and an option to add external battery. this consumes lot of space though.