I used the big powerbox eliminator, plus a smaller version and a big deep cell battery with a converter. I had no power for over 15 hrs or so. I ended up renting a gas generator when my power supplies started to run out. All in all, a pain in the butt, but ususaly power is not out this long.
The generator was great tho, recharging all my backups and I could watch TV and such
woohoo