Originally Posted by vanosracing
I can't speak for the 3 Series (E90's) but when I changed my battery last year on the 5 the indy programmed the new battery it to the iDrive system. I was told that with the electronics the alternator doesn't always run, the system monitors the battery charge and the alternator kicks in electronically. Also, people have complained of electronics issues or the battery life being shorter if not programmed. You would be amazed how much data modern BMW's store.
When I changed my battery I took the opportunity to drop-in a 7 Series AGM battery for that extra charge. Last thing you want on modern day bimmers is to lose charge.
What is even more frustrating in modern bimmers is the non presence of the dip stick. You can't even check your oil level anymore and have to rely on the iDrive system.
It's okay to try to better things, which in this case seems to be only to charge the battery when really needed, instead of continually charge it even if full. Progress is good, but over complicating the process is not progress. Instead of requiring manual coding, everything should be allowed to work seamlessly without intervention (coding).