I searched the forum and couldn't find the threads I thought I remembered with a similar issue. So am going to share what happened today in hopes that I might get some ideas.
This morning I started with a full charge and driving in Stealth mode. The CEL light was on (it had come on again on Friday morning, not sure why, possibly someone opened the door when charging). This used up most of the battery, but maybe could be expected at highway speeds with HVAC and wipers running. Distance = 29 miles.
Returning, on the freeway, at 60-70mph, I suddenly lost power as I was driving. I was going uphill slightly, and even with the pedal pushed to the floor, there was no power. At the time the battery range indicated 3 miles. The car quickly slowed to about 40, and then I thought to engage the ICE by putting into Sport. Although it didn’t react immediately, after about 30 seconds (or so) the engine kicked in and I had power again although it seemed to be in surges for a while.
We proceeded to our destination, found a charging station, and left the car for close to 2 hours. The car got 18 miles in range from the charge, which was down to 3 in about 5 miles of driving. (Very unusual in my driving experience. I don't get a full 50 miles from a full charge, I'm usually at about 80%, so should have gotten 14 miles.) It was at this 3mi range that the car again lost power (again at ~60 mph), and again shifting into sport returned power, after about a 30 second delay.
I called my dealer and reported in when we got off the freeway. All OK to drive.
Proceeding on, in sport mode, a whole host of lights came onto the dashboard and a warning on the command center that the battery was dangerously low and to immediately charge or to add fuel. (We had about half a tank at that point). There was a “power train fault” in the diagnostics. The electric fuel gauge also went orange, instead of white where you see how much fuel is remaining. (not the orange of sport mode, but the actual gauge level.)
As we were talking on the phone with our Fisker dealer, with the engine on, we noted that the error lights went off, the fuel indicator turned back into white, and the diagnostics went from orange to its usual white. It drove just fine to the dealership in Sport mode. We were only a mile and a half from the dealer, could drive on back roads, so decided not to get a flat bed ride.
One other thing I noted, the ICE was running kind of strange, it was as if I was pumping the accelerator up and down though I wasn’t.
What has changed since yesterday? Well, there is one thing. Anticipating a long day's drive tomorrow, yesterday I finally purchased a phone charger for the Karma. It plugs into the lighter style outlet. I left it plugged in overnight, with my phone attached. It looked like the phone was charging even when the car shut down. I think I should be able to leave the charger plugged in when I’m not driving, and even leave the phone attached, but that is the only thing that I can think of that has changed from the previous months.
Sorry for the long post, but am hoping someone on the forum has an idea. Thanks for your help.