I originally got this for use in the car as we traveled. Haven't been on a trip yet but instead I'm using it everyday to keep things cold while doing shopping, keeping the ice cream frozen on the way home, in general it's just great to have. When coupled with a hybrid vehicle, you can keep it running for an unlimited period of time by keeping the hybrid battery activated. If the hybrid battery runs low the car starts charges the battery and turns off again. Too cool.