My car battery died twice in the past month. The first time it was because I drained the battery when listening to the radio for a couple hours without having the car turned on idling. Now again, the car won't start. I think it's because it's been about 3 weeks since using the car due to storm Sandy. We couldn't get out of our town for several days since there was no street lights on. I hope we can get a jump from a stranger, but I thought it'd be a good idea to have a portable charger in case this happens again.