What can cause delayed alternator charging? on 2006 BMW X5

Alternator does not charge for 5 to 15 minutes after the first engine start of the day. After this delay I feel the engine surge with the alternator load coming on line and the alternator will charge 13.9-14v all day/night. No problems with subsequent starts. Next morning, same scenario. No alternator charge for 5-15 minutes , then it kicks in by itself. No fault codes from my OBDII scanner. Belt is not slipping and tensioner is tight. No unusual noise from the alternator. Alternator works just fine all day after the first 15 mminutes.

Asked by for the 2006 BMW X5
2 answers
could be bad regulator or other issues,seek diag as not to waste money
Oil dripping on your alternator...and alternator failure comes next...you can tell when the car seems possessed...lights going on and off and alarms going in and off ...then it dies...2k fix...thanks BMW for a great looking crap product