What's the worse thing that could happen with a dead battery? I was wondering because apparently my battery died today at the gas station. I've had some experience and trouble with bad alternators before, but this time it seemed to be the battery. (It was old, I'll get a new one, tomorrow) Once the tow-truck guy and my dad got it jump started, (with both their batteries,) I was able to drive it home (luckily only a few blocks). The wierd thing is that at the moment the car started, the headlights popped up unexpectedly, even though the switch was off. Could I have fried some headlight wires with the jump start, or before? I tried to turn them on once I got in the driveway at home, and although it was hard to tell with the dead battery, it seemed like they wouldn't come up. Any advice welcome.

 

Typically a low battery will let the alt to throttle all the way to wide open charge. Unless the battery has an open cell there is probably no real danger to the electrical system. The Delco alts will generally begin to back down on output when the voltage exceeds the 17 volt threshold. It is possible while jump starting to generate a voltage spike which in fact can cause serious damage. You should not need 2 batteries for a jump start assuming the connections from the donor vehicle to yours are good. Thats why despite what you read I recommend that the donor vehicle be OFF while attempting a jump start. If the jump connections are tight there is no benefit at all to the donor vehicle running and the potential for damage is reduced for BOTH vehicles. Most likely the wiring is OK, when it burns you'll know it. You could have simply popped a fuse. Get a good battery and check all connections and you should be OK. With a charged good battery you should see around 14 volts a little off idle from the alt.

 

My car is ok. It was *just* a dead battery. I think I need a support group not a message board!

 

lol, glad you got things fixed!