I have a recurring charging problem. I normally plug in the car every night. Often, perhaps a few times per week, charging is aborted during the night and I find red LEDs when I unplug the cable in the morning. The car reports "12V battery low" and predicts various dire consequences. Sometimes, the 12V is really low, and the displays do not work. Items like the remote and the door handles still work in this condition. Pressing the brake pedal to turn the car on and getting back out of the car to turn it off again clears the alarms and starts trickle charging the 12V battery. A few minutes later, everything works normally. I've called Tesla Roadside Service a couple times when the car has been in this condition. They tell me that the logs show that the car "lost connection to ground" during the night and has aborted charging for that reason. Trickle charging to the 12V battery is also interrupted as a safety measure due to the first error message. TRS do not have any good solutions to the issue, just a suggestion to try turning the connector plug upside down in the wall socket. The problem comes back, no matter which way the plug is inserted. The problem does not seem related to a particular wall socket. This happens both at work and at home. I'm located in Norway, where our electrical grid is slightly weird. It is a 230 V AC grid, but both phases are live at 130 V to ground. The 230 V between phases is due to a constant 120 degrees phase difference between the two conductors. There is no neutral conductor, just two live conductors and a protective earth. The voltages between the phases and ground can vary over time, depending on what else is connected to the grid. The display in the car reports anything from 228 to 239 V line voltage from day to day. I have not been able to pinpoint exactly what conditions trigger the error condition, but it seems to have become more frequent in the last few weeks. Does anyone else have this problem? Any advice on how to get rid if it? Any chance of damaging the 12V battery permanently? I suspect that discharging it completely several times per week in freezing temperatures does not really improve its health, if it is similar to other lead/acid batteries. I go away on business trips for several days or weeks at a time, and it is not clear if I am better off plugging the car in or leaving it unplugged. What happens if it panics on the first night and then slowly drains the batteries for two weeks in sub-zero temperatures?