Battery Powered Powerhead?

I know that the Vortech powerheads have an option for a backup battery pack, but they are really expensive which makes them impractical as an option. Can't you just use and extension cord from the house?
 
How about using a UGF plate and a battery powered air pump. Or you can get a bilge pump and run it off of a 12v battery. Walmart and bait shops sell the bilge pump type already converted to live well use.
 
i had a power outage for 3 days in december, used a live bait pump which oxygenates as well(off the boat) it ciculates 800 gallons per hour and it ran for nearly three days off one charge. cost me 45 euros,sure its going to be cheaper in the states.go to a good boat/fishing store and see what they have available.
 
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