Ah, I didn’t know if it needed replacing or not.
All BMWs made after like, 2002 need to have the alternator calibrated when a new battery is installed. It’s because the alternator “learns” from the battery how good or bad it is, so the alternator will work itself harder to keep the battery optimum. If you don’t calibrate w/ a new battery, it’ll continue working harder and fuck your new battery up. I miss the days of buying a $60 battery from AAP and being good.