Not true at all, the battery is really only there to start the thing (basically). If it couldn't be powered by the alternator alone, (and needed the battery power also to run) the battery would eventually die.....think about it.......
Yes, but typically you drive at high and low speeds so it evens out and does charge the battery some.
In most modern cars the alternator is, under some conditions and especially at idle, not capable of supplying the full electrical demands of the vehicle. Just the way it is...can you drive 55mph on your alternator alone....maybe....through the neighborhood at 15 with your lights on..no way.
Red Hot Trail Boss
Last edited by robbpoe; 04-06-2017 at 11:50 PM.