Sorry guys I feel kind of dumb asking this question... I have in front of me two UPSs, one a Powerware Prestige 1.5kVa, the other a BEST USP1.4kVa. Why is the BEST more than twice the size? I would think that given the same capacity they would be the same size.
The Powerware uses 5 YUASA NPX-25 batteries whereas the BEST uses a single Johnson Controls 12V 75AH battery. The transformer in the BEST is simply huge, while in the Powerware they're three much smaller toroidal transformers. But both advertise nearly the same capacity.
Is one significantly 'better', or has technology given us smaller UPSs for the same capacity?