The Washington Post recently published an article about cold-weather EV performance, and as it points out, the need to heat the cabin is one of the biggest factors in why EVs lose so much range when it’s cold out. Freezing temperatures do affect battery performance in general since they operate best at around 20 degrees Celsius. But keeping the cabin warm is a much bigger factor.
Cars with an internal combustion engine don’t have nearly as much of an issue with this, but it’s not because engines are more efficient than electric motors. It’s actually because they’re much less efficient. Only about 20 per cent of the energy produced by a combustion engine goes to driving the wheels. The rest is wasted heat that also happens to be useful for warming the air that gets blown into the cabin.
Since electric powertrains generate a lot less wasted heat, EVs need to actively heat the air that gets sent into the cabin. That requires electricity, though, and reduces range. But by switching from electric resistive heating to a heat pump, you increase efficiency and don’t lose nearly as much range. The difference is significant.
When Recurrent studied how much range EVs lost in the cold, it found that the Bolt lost 32.6 per cent of its range. The Jaguar I-Pace, on the other hand, lost only 3.0 per cent. The Audi E-Tron, Tesla Model X, and Tesla Model Y were some of the other top performers in the study, while the Ford Mustang Mach-E and Volkswagen ID.4 were among the worst. That’s largely because a heat pump is three or four times more efficient than resistance heating.
If you’re in the market for an EV and want to minimise range loss in cold weather, it makes sense to prioritise ones that have a heat pump. But if you already own one without it, one suggestion is to pre-heat your car before your drive while it’s still on the charger. You’ll still use extra electricity to keep it warm, but at least you’ll start your drive with a full charge and a warm cabin.
And as the Post points out, fears that EVs trapped in the snow can’t keep their occupants warm as well as ICE cars can are seriously overblown. When Car and Driver tested a Model 3, which doesn’t have a heat pump, it was able to keep the cabin at 65 degrees for 45 hours. If it had been equipped with a heat pump, that number could reportedly reach as high as 60 hours. So while winter range loss is definitely an issue, there’s no need to worry about freezing in a traffic jam as long as you keep your car charged.