I drive an hour and a half of stop and go traffic every weekday, and only get to drive at highway speeds during the weekend. However, I have not had issues with the battery or with charging, in over 9k miles. I would attribute any instances of the battery going bad to defects in the battery or alternator, not to any design issues. I am confident that a normally functioning battery and alternator would not develop any problems even when the car is driven few or no freeway miles.
Originally Posted by ssj
How many freeway miles do you drive daily? There have been sporadic reports about the battery going bad when you do not drive enough freeway miles for an adequate charge.
ED on Sep. 28, 2010: 550i Dark Graphite Metallic, Oyster/Black Nappa Leather, Anthracite Wood Trim, Convenience Package, Driver Assistance Package, Premium Package 1 (Std.) & 2, Sport Package, Sport Automatic Transmission, Dynamic Handling Package, Active Cruise Control, Head-Up Display, Side and Top View Cameras, 4-Zone Automatic Climate Control.
Retired: 2008 528i Space Gray.