excuse reviving this 'tense' topic and my lack of writing in German..... I can read and understand it quite well though
On the KTM 1*90 bikes, the cigarette lighter plug is connected to ACC1 through a 10A fuse to the battery, so no fancy electronics are involved and most chargers can be connected here.
What bothers me a bit, is that these fancy chargers, like the CTEK MXS5.0 and most other multi-stage chargers, can, during some of their charging stages, supply voltages that exceed 15V - in the CTEK case, 15.8V during desulphation and reconditioning...
I just wonder what the SAFE maximum charging voltage for the KTM electronics is? (assuming some electronics is still active when the bike is switched off)