Hi Cookey, based on what you have written the F750 is indeed detecting that the power supply is at 12.3V or below for a few minutes because this is the criteria for it to voice that message and shut down. Mine is set to 12.1V and even then it will shut down when I am vacuuming the car as doors are open and courtesy lights are on and this will cause the voltage to drop to that level. Every car is different and if yours has stop/start technology then you'll find that the battery is in a permanent state of partial discharge, so anything between 12V and 12.5V is perfectly normal. What you need to do is what the rest of us have done is set that threshold in the F750 to the lowest that you feel happy with and the car will start. Quite possibly this will be less than 12V but I and other dashcam owners I have discussed this with all agree that we don't feel confident with less than 12V and are not willing to find out what setting the car won't start at, for obvious reasons. So as I stated mine is set to 12.1V and this tends to give me somewhere between 6 hours and 18 hours of parking mode depending on the state of the battery when I park. As you may have seen there is also a timer and the maximum this can be set to (and I think is the default) is 48 hours, so there's no point trying to set a threshold voltage which will allow the parking mode to be longer than that.