Originally Posted by mr_milo
Thanks for the info. I started digging around and found out about that too. The BMW's Brake Energy Regeneration system
apparently only charges the battery "when you take your foot from the accelerator or apply the brake", therefore even if you are driving the car it may not be charging the battery!
They even acknowledged that "today's vehicles require much more electrical energy than older models, due to the much wider array of electric and electronic on-board comfort and safety systems", yet they think allowing the generator to only be active at certain times somehow makes good sense????
Needless to say I'm disappointed in BMW.
I'm not disappointed in them at all. I think this is a great feature, and it contributes to the fact that my car gets simply astounding fuel economy for its size and performance capabilities (and the way I drive it). One of the reasons we buy BMWs is for the advanced technology, but sometimes being on the bleeding edge can cut you a little bit. I bet the F3X has fewer of these sorts of issues as they have probably improved the system. To put the efficiency into perspective, my tiny little FIAT Abarth is only getting 2-3mpg better both city and highway than the BMW. And it is 1000lbs lighter...
If I wanted boringly reliable I would drive a Camry.
I will say, *I* think there is something wrong with your car and the dealership just has not found it yet. You probably had a wonky battery almost from the get-go from the sound of it. As I said, I often use my car less than you do yours, and even if I don't plug it in I have no issues. I am just doing it so the battery lasts longer. I hope you find the issue!