Thanks guys for your great help! My Fisker Karma is back to life, the reason for the "blackout" is pretty much mysterious:
I have also thought, that the batterie of the FOB might be empty. I could not check this out, because i did not have the reserve FOB with me.
The other issues you have brought up, were problably pretty close to what has happend to my Karma. I think that I have had a problem with my 12 V battery.
So what i did was, I threatened my Karma to bring in a tender and a jumper cable to kick him into his electric ass, if he did not come back to live and start the booting process.
Yesterday morning I approached my Fisker, that has been disconnected the whole night. I connected the car and started the booting process. Some kind of wonder: everything was fine! Booting performed all the way through and i could start of. No need for the fender or the jumper cable.
Maybe my Fisker wanted to stay the night out on his own without me; I have been on vacation last week, leaving the Fisker alone at home !
In order to be serious: does i make sense to use a fender, if you don't drive the car for some time ( 1 or 2 weeks )?
During the week I very often drive very short tracks in the city between 4 - 8 kilometers - one way -. Maximum 5 - 10 Minutes. Does it make sense to use the engine and drive in sports mode in order to recharge the 12 V battery?
Thanks a lot again!