Loss of range in cold weather

[jadnashuanh]

An a/c running full tilt after the car has been sitting in the hot sun and the car heat soaked to maybe an interior temp well over 110-degrees F with the fan running fast enough to do much of anything takes a fair amount of energy to make comfortable, too. The BEV with a heat pump can be quite efficient. It's where the battery is also cold or you need electrical resistance heating where you can suck up lots of watts making things go. It's easier to be fairly comfortable when it's cold out since you can add a layer(s) of clothing...there's a limit on how much you can take off in the summer!

The range estimate makes lots of assumptions, and is often proven wrong depending on your current trip verses the previous one(s). How many times you have to re-warm the car after a stop can affect things significantly verses just puttering along on a single trip.

 

[fdl1409]

While the battery capacity is showing only 2% less energy stored, what you are missing is that the colder battery will not deliver that capacity.

It does deliver that capacity.

We had the coldest temperatures in late november, for example -5.7°C ( 22°F ) on the 25th.
I charged on the 27th after driving 129km in 2 days. Before charging battery capacity was 1.2 kWh according to the service menu, SOC was 7%. After charging max. capacity was indicated to be 19.3 kWh, actual capacity 18.9 kWh. That is a difference of 17.7 kWh added for 93% SOC. My power meter showed 20.2 kWh were drawn from the grid.

For comparison on 16th september after 144km ( 90 miles ) SOC was down to 12.5%. Capacity bevor charging was 2.2 kWh. After charging max. capacity 19.6 kWh and actual capacity 19.3 kWh. So 17.1 kWh were added for 87.5 % SOC. Power meter showed 19.6 kWh from the grid.

17.7 kWh for 93% SOC makes 19.03 kWh actual capacity for 100% SOC.
17.1 kWh for 87.5% SOC makes 19.54 kWh for 100%.
Difference 2.7%.

That indicates that capacity loss due to temperature is responsible for only a relatively small part of range loss. Other factors are more important.

Frank