...you should get a BMW battery charging system (P/N 82 11 0 026 663 MSRP: $69.00US). Plugs into a regular 110v outlet; the other end plugs into your cigarette lighter. This is no big deal. Due to the increasing volume of electronics in all cars, there is more of a drain on batteries than ever before. Many cars, if left for a week to 10 days, will need to be jump started. That's why I keep my Porsche 928s4 plugged in.