fwiw I've had good luck with this small generator with a built in 12v inverter, it powered lights, radio etc in the evening a couple years back when we were without power for 9 days. Add a $12 car adapter and you can recharge it from your car, or take it to a friend's house with power and plug it in. When the lights go out, your ability to deal with an overheated UPS could be compromised, I recommend using something safer by design.

http://beprepared.com/product.asp_Q_pn_E_CM%20P400_A_name_E_ALL-START%AE+Emergency+%27One%27+Power+Generator