The unexpected tech that could help your EV battery in the cold

In freezing temperatures, a typical electric vehicle can lose a lot of battery power. The range on a Chevy Bolt or BMW i3, for example, can be cut roughly in half. But adding a heat pump can help solve a large part of the problem, which is why the technology is beginning to show up in a growing number of EVs.

Winter affects EV batteries in two ways. First, lithium-ion batteries work a little more slowly in the cold, so they’re less efficient. But the biggest issue comes from turning on a car’s heat. The first generation of electric vehicles kept passengers warm with resistive heating, which quickly drains the battery.

Gas cars don’t have the same challenge—ironically, that’s because they run so inefficiently, generating a lot of waste heat. “If you’re on a road trip and you put your hand on the car, you can feel the heat of the engine. . . . It can channel that waste heat into the cabin to warm the passengers,” says Andy Garberson, who leads research at Recurrent, a company that analyzes EV data.

If an EV switches to a heat pump instead of using resistive heating, the battery range can improve significantly. Recurrent studied real-world data from 18,000 EVs on the road in different weather conditions, comparing those that had heat pumps with those that didn’t. Tesla Model S cars with a resistive heater, for example, lost twice as much range as a newer version of the car that had a heat pump instead.

The heat pumps are shoebox-size versions of the ultra-efficient technology used in houses for heating and cooling. (In U.S. homes, heat pumps have outsold gas heaters for the past three years; they’re especially popular in cold climates like Maine, where the state surpassed its 2025 goal for adding new heat pumps two years early.) The tech works by transferring heat from place to place, rather than generating it.

It’s not yet ubiquitous in cars; Recurrent has tracked 32 models with heat pumps so far, out of around 70 different EVs on the market in the United States. Some cars offer it as an option. Audi had to stop offering heat pumps in some models because of supply chain shortages, and then made the feature optional. (Since so many electric cars are sold in California, where heat pumps are unnecessary, it’s not surprising that they aren’t standard.)

Still, EVs are feasible in cold climates even without heat pumps. First, if you have a garage, you can increase battery range by heating up your car when it’s still plugged in, a step sometimes called preconditioning. “When I went to the gym this morning and it was 3 degrees, I started my car in the garage,” Garberson says. “The vehicle was plugged in and I was using energy from the outlet to warm my car from 3 degrees to 70 degrees. When I got in my car and unplugged, the car only had to use energy to maintain the 70-degree temperature.”

And, he points out, most people rarely need the full range of their car on a typical day. “My vehicle, even in cold conditions, will drive 200 miles,” Garberson says. “It was 4 miles to the gym and then 4 miles back. So even in freezing conditions, temporary range loss in cold weather is not something that affects my daily driving. That’s why, for most EV drivers, they’ll tell you that they don’t even notice range loss in the winter.”