It has been said often before, but it is important enough to be stressed over and over again: There are no secrets when it comes to the BMW OEM charging system. I would argue that the system isn't even error prone when maintained properly. The BOSCH components used have decades of heritage and are proven. That is true for the stator, the rotor, the voltage regulator (mech or elec) as well as the rectifier (diodeboard) none of which is complicated nor do they contain advanced technology. So why are there reported issues at least once a week? Because the implementation BMW choose and because people amongst other things use heated gear and aux lights and are practically wringing the system. Hence, if not perfectly working, it'll not sustain those loads over an extended period of time and exhibit the know problems. What can we do preventively: proper grounding (especially of the diodeboard) is absolut key keep contact resistances at a minimum (clean electrical contacts on stator, diodeboard and voltage regulator regularly and use dielectric grease) watch out for oxydation on connectors check alternator brushes and the copper surface of the two sliprings on the rotor regularly (carry know good spares on longer travel) It isn't rocket science, just proper maintenance like everything else. It works for me. FWIW: The one time I helped a fellow rider it was ... the diodeboard. The one time my own system failed, it was ... the diodeboard.