I have seen this done. Basicaly, I believe it needs to be charged, probvably with a charger terminated in aligator clips to attach to the terminals. Then you would have to run a power invertor off of that. So battery->4-pin->male 4-pin to power invertor. I think this would work, but again I am not sure. The only thing I can otherwise think of is to pick up one of those big portable dc car starter deals. They have a 12/20 if you get the big ones. You then would plug the invertor into the unit using the cigarrette adapter since the unit has a 12v dc power vsource via the cigarette input. I hope this makes sense.
Daryan