[CaptainHaplo]

Unfortunately - 12 volts isnt the only concern.

The problem isn't voltage in reality - its amps. A normal aircraft cig plug is rated at 3 amps. I looked on the page and could not find a amperage rating for the device. Before you go ordering one and trying to do a battery pack, check the specs and find out what amperage the cooler requires.

What you want to do is match the amps and volts both to the device, that way your getting maximum life out of the battery and little chance of overamping the device.

Also - you need to look into a charging unit of some type if you go this route.

I assume your having major maintenance done by a A&P licensed mechanic. If so, talk to him about putting an additional plug near what will become the "storage" area so you can just plug it in. If the existing plug is out due to a fault in the plug, no biggie, but if its an electrical problem elsewhere - that really needs to get looked into anyway. Adding a plug wouldnt be that difficult, provided there is room for the modification (wiring under the floor). If regs prohibit an under the floor mod - you can alway correct the problem with the existing plug - and move it (wires under the carpetting) to the rear of the cabin - depending on the plane.