The second and third one are about 300watts of backup power.
There are runtime charts on both these sites. Both are about 20watts for 120 minutes.
I use one similar to the APC for some pumps. They work standalone without a computer/software.
The second one
http://www.apc.com/shop/ca/en/produc...prod_store03-2
The third one
http://www.tripplite.com/energy-savi...ort~ECO550UPS/