What Does a BMW Alternator Do?
Image: BMW X6M Series Alternator with just 26K miles for sale at MT Auto Parts for £237.74 The alternator is one of those BMW parts that works quietly in the background until something goes wrong. While the engine is running, it generates the electrical power needed to operate the car's systems, from the lights and climate control to the infotainment, heated seats, sensors and control modules. It also keeps the battery charged so there is enough power available for the next start. If the alternator stops charging, the BMW will continue running on battery power for a limited period, but how long it lasts depends heavily on the battery's condition and how much electrical equipment is being used. A modern BMW has a significant electrical load, so it is not safe to assume that a car will continue running for a fixed 20 or 30 minutes. Once the battery voltage drops too far, the engine can stop, and the car may no longer restart. The battery warning light appearing while driving is o...