[comptiger5000]

Tweety - With bigger, or dual alternators, and chargers kept running when the cars aren't in use, so they start each day with full batteries, the batteries could be kept charged enough. As far as having to use fuel to recharge the batteries while driving, yeah, that's true. However, the little bit of extra load is less of a penalty than having the engine idling with almost no load (particularly with gas engines, not as much with diesels).