Mine is ~14.1max when vehicle is running.
And ~12.6 when vehicle is off and trickle charged.
Clear existing codes.
After you started your vehicle your voltage should be 13.5 to 14.4max, if it is under charging with all the options turned on, try to increase your RPM, check again.
This is just one of many voltage charging issue, it could be any of the following:
- system glitch
- loose serpentine belt
- bad pulleys or tensioner
- alternator voltage regulator
- rmfd alternator with BMW logo but made in Mexico
or worst China
Edit: adding
- 90amp versus 120amp versus 140amp alternator ( did you checked or recorded your orig alternator specs before the dealership replaced it?)
Also, if it is under warranty ( 2 yrs parts and workmanship ) so why stress over this, just have the dealership do the diagnostics
My x5 has the cold climate option, with a 140amp valeo to power the heated seats and related accessories