Doni vuoi dire che il tuo manutentore non è quello originale BMW??
Questo è quanto ho letto sul manutentore originale BMW:
Genuine battery charger for all motorbikes even the new BMW bikes with CAN bus electronic like the R1200GS, R1200GS Adv. , HP2, R1200ST, R1200RT, R1200S, R1200R, K1200S, K1200R, K1200GT, K1300S, K1300R, K1300GT, F800R, F800S and F800ST. It is easy to use, just plug the connector into the on board socket and charging will be automatically done. This is the only charger that works with CAN bus systems over the on board socket.
All others will be banned after about 15 mins of charging. 
Lynx_68