How bad is EV in extreme cold weather

EV is not for cold weather. But how bad it can be?

Today I watched a video from this article and have a better conclusion.

TL;DR

1. 33% of battery lost/drain in cold weather.
2. Battery cannot release as much energy as in ideal temperature.
3. It cost a lot of energy to heat the cabin!

For demonstration only, not the real EV battery graph

Battery

People who have been to a cold place has some experience about their camera or cell phone battery dies much faster than expected. It is no secret that battery best performance is between 20C to 30C. Therefore, some EV like Tesla has a component that helps to heat or cool the battery to the best performance temperature.

The dilemma here is that temperature regulation costs energy too!

Heat the Cabin

Practically, no one want to sit in the fridge. So heating up the cabin is a must for the car. The cabin is poorly insulated because of all the glasses and metal shell. So the AC must work hard to keep it up.

Also the AC is a heat pump which has higher efficiency than pure electricity heater. But the lower the external temperature, the less effective the heat pump is. Thus increasing the energy cost.

Therefore, it requires significant power to run the AC in cold weather.

Gas powered car has a better solution for this problem. It harvests the heat from the engine to heat the cabin. Therefore, the heat which originally shall go into the environment now goes into the cabin.

Calculation

Like numbers? Here are the raw calculation based on the video

The car the author has shall have about 75kw battery. I calculated the energy used in driving is about 40.6kw. The battery reserve due to cold weather looks like about 10% and the display shows 3% battery left. Therefore, the lost of capacity + AC + Battery heating + misc cost is about 25kw in 2 hours.

Conclusion

Although I like my Tesla and I am holding some Tesla stock, I usually give the advice that EV is not for cold weather.

If you are living in a warm place without extreme low temperature, EV is the best choice.

The benefit of using EV in warmer place is much bigger than the gas cars.