[kcrane]

Some interesting stats... charging on a Podpoint home charger, 6kW being supplied but the time to top up from 80% to 100% says over 24 hours

The clue is in the lower right. I'd plugged in early in the morning and the heating came on set at 20C. All 6kW were being used by the heater. As soon as I turned off the heater the time estimate dropped to below 3 hours.

I think this explains what seems like poor efficiency over the last few weeks. I always drive with the heater on and sometimes pre-heat. If that pulls anything like 6kW it could explain why I am getting below 3 miles per kWh on average.

 

[CoWplagued]

When the car is plugged in it will max out all the heaters to get the car ready for you to drive. When you're driving it will try and use the most efficient method of heating available, using heat from the inverter and motors as well as the resistive heating. So if you want to have the best range and don't care about total power consumption always preheat while plugged in.
It won't really take 24 hours, after about 20 minutes that 6KW would drop to around 2KW once everything has warmed up a bit and then drop again if temps stabalise.

 

[AMP_it_up]

The heating will come on if you are sat in the car, which is why you got the 24+ h estimate, as most of the power being drawn from the Pod Point is for the heating. Once you get out of the car the heating should go off (unless set to preheat) which will result in a more normal charge time.

I understand from Bjorn Nyland that the M3 can take power from the battery even when plugged in to a charger under extreme conditions, e.g. extremely cold outside and connected to a 7.5 KW charger. This happens when the power draw to heat the car and the battery is greater than the charger can supply.

 

[Spike]

Bjorn talked about power draw in a video earlier this week. The heater and battery heater can draw in excess of 11kW combined initially, so that may help explain low efficiency in cold weather - when preheating even when plugged in you can find you've used some battery.