2006 650i Mis firing

I started my car on Saturday and the engine misfired miserably. The service engine light displayed and I called the dealership service advisor. I was told to shutoff the vehicle and they would dispatched out a tow truck. After shutting the vehicle down and quick restart to put back in the garage. The fault cleared and the engine ran with not faults. The dealer informed me today that my battery was weak and possibly needed replacement for a price of $400.00. Again the service advisor stated that the battery would need to be serialize to my car. I am not sure about the battery! Any suggestion and help would be appreciated

The 6er puts a huge drain on the battery due to all the electronic sub-systems. When the battery starts to fail due to age it is common for the car to have multiple random errors due to the lack of voltage - things like rough engine, emission warnings, transmission errors, etc...

If your battery is about 5 years old then I would replace it. If it's less than 3 years old I would have it tested by your local PepBoys or AutoZone for free before replacing it. An OEM battery costs ~ $220 at the dealer. You can buy just the battery and have a BMW indie mechanic install it and have it registered for a lot less than what the dealer charges.

Registering the battery tells the computer that a new battery is installed which changes the way the battery is charged. As the battery ages the car will increase the voltage when charging.