Most of you probably don't use one, but if you do, here is some important info.
New computers especially from Dell and HP use Active PFC power supplies. Maybe all new PS units will be PFC style soon. My machine is Dell XPS 9000 and has a PFC PS.
A normal battery back up creates a "stepped sine wave" when on battery. The Active PFC power supplies don't like this and wont work. There are some reports that some PFC do work but you wont know till you plug it in.
So yesterday when a storm came through and the lights went out for 1 second, my system switched to battery then my computer shut down. Its like I have a $100 power strip, totally useless.
I called APC and after some testing he explained it to me and then I searched that and found more info.
So the solution is to get a UPS that creates a "pure sine wave" or "sine wave". Of course that costs a lot more. They are usually sold for business servers.
500w smt750 $319 ---- amazon $286
670w smt1000 $ 459--- amazon $395
550w pp800sw $ 269 ---- amazon $222
700w pp1100sw $ 319---- amazon $249
So I'll probably get a CyberPower. Also the reviews indicate that the fan runs 100% of the time on the APC units and its loud.
These companies need to make a home version for sine wave that doesn't cost so much.