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      05-16-2009, 07:11 AM   #55
HP Autosport

Drives: F80 M3
Join Date: Mar 2007
Location: Santa Barbara, AP, Brembo, GIAC, Koni, Ohlins, Performance Friction,

iTrader: (34)

Originally Posted by lucid View Post
Are you sure about this? If such a long trip does not charge the battery, I don't know what would. Seriously, how else would the OEM battery be charged? Then all the people commuting short distances to work in city traffic (like myself) should end up with dead OEM batteries within weeks...
Your alternator will mantain a proper charge on your battery. An alternator is not a battery charger by any means, unless you can turn off all power consumer with the engine running, it's not going to charge the battery at a fast enough rate nor will it likely to reach full capacity.

I don't know the exact number, but there is probably 140-180 amp draw with all electronic consumers running. At that level of draw, all your alternator can do is supply power to the consumers.