When I first started driving, I believed a car battery got charged fairly well by a running vehicle. So if you had a dead battery, after a jump start, running the vehicle for say 45 minutes would charge it up fine. But over the past few years I have been reading that in reality it charges the battery very little. And that to really charge the battery to its previous state requires a dedicated charger. Last week I was out of state and left a dome light on in my car for 5.5 days. :| The battery seemed completely discharged by then because even the power door locks didn't work. A friend gave me a jump start and I drove the car about 35 minutes home. Ever since then I've taken standard ~10-15 mile trips and the car has started up just fine, which is pretty surprising given the 30° F avg temps. It seems to me that the battery is being charged more than I understood it to be. Or maybe I'm pushing it and going to be stuck with an inadequately charged battery any day now? If I'm not back in the thread in 30 minutes then you guys can be like "duh!".