AussiePete
Established Member
A very non-scientific experiment.....
I’ve asked on a few forums about the benefit of pre-heating the car on very cold days to try and avoid the initial cold running mi/kWh effect and the general consensus was it wasn't worth it.
Well after a particularly poor run when I got 6 miles for around 5kWh and then 10 miles for the second 5kWh (16 miles total) without any pre-heating of the car, I thought I'd do some testing.
For my test the vehicle was fully charged and outside temp was 0. Before driving I plugged in my 7kW home charger, then switched the car fully on and turned on HVAC for 30 mins. This meant the battery was in use (either taking on charge or discharging to run heating) and as such the battery was getting warmer. It also meant that the internal car temp was very comfortable.
I then went for a drive, 30-50mph and the first 5kWh gave about 9 miles, with the second 5kWh giving 15 miles (24 miles total). Same road and speeds as the initial run - so 24 miles for the same consumption as 16 miles on the previous run.
Now as I say it's not scientific, and requires a bit more testing, but pre-heating the car - either by charging or discharging the battery before you leave, does seem to reduce the very poor mi/kWh cold start effect.
Notes: My car is a 3 year old MK1 ZS and battery health was reported as 97% at last service (last month). I haven't used the mi/kWh figures from the GOM as I've found that they are way out in the initial miles of a gold run. For example on the run which gave 6mi for 5kWh the GOM was read 3mi/kWh
. Lastly I'm working roughly that each notch on the battery guage is around 5kWh.
I’ve asked on a few forums about the benefit of pre-heating the car on very cold days to try and avoid the initial cold running mi/kWh effect and the general consensus was it wasn't worth it.
Well after a particularly poor run when I got 6 miles for around 5kWh and then 10 miles for the second 5kWh (16 miles total) without any pre-heating of the car, I thought I'd do some testing.
For my test the vehicle was fully charged and outside temp was 0. Before driving I plugged in my 7kW home charger, then switched the car fully on and turned on HVAC for 30 mins. This meant the battery was in use (either taking on charge or discharging to run heating) and as such the battery was getting warmer. It also meant that the internal car temp was very comfortable.
I then went for a drive, 30-50mph and the first 5kWh gave about 9 miles, with the second 5kWh giving 15 miles (24 miles total). Same road and speeds as the initial run - so 24 miles for the same consumption as 16 miles on the previous run.
Now as I say it's not scientific, and requires a bit more testing, but pre-heating the car - either by charging or discharging the battery before you leave, does seem to reduce the very poor mi/kWh cold start effect.
Notes: My car is a 3 year old MK1 ZS and battery health was reported as 97% at last service (last month). I haven't used the mi/kWh figures from the GOM as I've found that they are way out in the initial miles of a gold run. For example on the run which gave 6mi for 5kWh the GOM was read 3mi/kWh
. Lastly I'm working roughly that each notch on the battery guage is around 5kWh.
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