I own an APC Backup RS 800va . I started the ups today , and "replace battery" led flashes.
I called the local stores , noneone of them has the replacement battery in stock. Can i use other brand batteries? Also There isn't much info on the batteries.
it is written that .
"Cycle use 14.4 * 15.0V" (20C)
"Standby use 13.5-13.8V"

It is not clear what these specs are , other brands don't have these specs.

If i can't find replemencent batteries at a reasonable price. Then i will buy a new UPS .
Online ups's all have always on fans. So they are out of question.
All interactive ups 's i can find , has modified sinus wave outputs. So i can't buy one with pure sinewave.

if found two models from FPS.

Ep series is slightly more expensive . it is not clear what difference do they have besides the LCD screen.
They both have fans , but again no info if they work all the time , or only when charging . If they work all the time , then no point in buying a lineinteractive model in the first place.

Does anyone have any experience with these FSP UPS'es?

i will use the ups with my personal computer . 750W psu desktop and 26 'monitor.