BMW basically uses an algorithm with the ECM and other modules to determine how to cycle the alternator. A new battery wont require as much "effort" as an old one. It's all the in name of emissions and fuel economy.
If you think thats stupid, that's only the tip of the iceberg with them. Electric water pump(s) (yes, multiple water pumps that are electric on an engine), a single wire comm network used with the water pump and other stuff that shouldnt even need a comm system, water leaks that fry 3-4 modules and cause corrosion on network splices/wires.
Footwell modules that shit the bed when the battery dies, or voltage drops, or the car is jumped (even correctly), no used modules, coding of modules, blah blah blah.