[Wombat101]

I'm most definitely automatively challeneged, but pelase explain all this talk about alternators?

I was under the impression that the initial charge to turn the engine over came directly from the battery, with the alternator merely carrying the load until the generator spun up to speed, at which point, the alternator still spins, but does not generate power. It is the generator which then creates the electrical energy necessary to run the engine (and accessories) and recharge the battery.

Am I wrong, and if so, please enlighten me?

[coloradan]

Alternator = generator. Only works when the car is running, so you need a battery to get it moving in the first place. After the engine gets going, the alternator handles all electrical tasks, including recharging the battery, until the engine goes off. The issue arose because the Peltier effect devices run off DC power. Lots and lots of DC power.

[JAKraig]

There is no generator, they were replaced decades ago with alternators, the alternator recharges the battery and is on the same bus with the battery. When the bus voltage falls lower than the source of the highest voltage on the bus that source provides the system power. Sometimes it may be the battery but most of the time when the engine is running it is the alternator.