Quote Originally Posted by j cat View Post
lead acid batteries need be charged fully at all times. when they discharge[supply power] they must be charged in a short amount of time . the more you discharge a lead acid battery [frequent starts] the shorter the life.

when operating a vehicle and the alternator drops out the discharge frequency increases this causes damage to the cells due to heat generated when the alternator starts charging the battery. heat is what also kills these batteries. like on some of these new vehicles the battery is up against the fire wall not the best place to put a battery to avoid heat since the air from the engine/radiator is in that area.

light loading of the alternator is best since it will reduce brush commutator wear . the windings and regulator also get damaged from the heat created with the constant hard charging of the battery so you can save a little fuel or perhaps for GM to pass some EPA mileage law.
So basically you're saying that the current electrical setup for GM vehicles is to lightly load the alternator (thus reducing some drag on the engine) and use the battery as a reserve to improve fuel economy? My thing with that is that the battery would eventually drain to a point where it would no longer be a reserve and the alternator would have to work really hard to charge it up.