Cold Snap: EV Owners Face Reduced Range, Longer Charging Times

Much of the continental United States is shivering under an arctic blast. It’s 8 degrees in Chicago and 15 in Atlanta. Much of the country will see little relief for a week.

You wouldn’t let your car run out of gas in this scenario. If you’re driving an electric car, you must be even more cautious.

“With Chicago temperatures sinking below zero, electric vehicle charging stations have become scenes of desperation: depleted batteries, confrontational drivers, and lines stretching out onto the street,” the New York Times reports.

Electric vehicles (EVs) lose range in the cold. There’s nothing unique about that as gas-powered vehicles also lose range in the cold. But refilling a gas tank takes a few minutes while recharging a battery takes much longer.

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Some EVs are far worse than others. Recurrent, a company that tracks EV battery life and uses machine learning to help owners care for their car’s batteries, studied the range of many cars under different weather conditions.

A study the company updates regularly finds that 18 popular models kept “an average of 70.3% of their range in freezing conditions.” However, the results differed drastically from model to model.

Range Loss In 12 Popular Models

Recurrent compared the measured range of 12 EVs in ideal temperatures — “the temperature at which a specific model sees its highest average range,” which varied for each car — and below freezing.

The company specified model years for some cars but not others — an important caveat because battery technology improves regularly. Tesla, in particular, is known for updating technology during production, so two Teslas of the same model built a month apart may have different batteries.

Some EVs use heat pumps to extend their range in the cold. That works in some temperatures. But Recurrent found it often works best above 14 degrees. This cold snap cancels it out in many parts of the country.

Charging Stations Slower Too

EV owners typically do most of their charging at home. But those stuck looking for a public charger in this cold have faced an unexpected shock — charging stations can also slow down in these temperatures.

CBS News Chicago sent reporters to several charging stations, where they found “some of the stations weren’t working, and those that were were taking a lot longer to charge.”

One driver waiting in line to charge said he’d seen “at least 10 cars” towed because their batteries died while waiting in line for a charger.

Cold Weather Tips for EV Owners

The nightmare stories from Chicago point to one critical fact many EV owners may not know: in most of today’s EVs, you can run only the heater and nothing else to stay warm but conserve power.

You can’t heat a gasoline-powered car without running the engine. But most EVs have a mode that draws just enough power from the battery to run the heater and electronics without moving the car. An EV’s battery can last surprisingly long under those conditions. In some tests, EV owners have kept the cabin at a comfortable temperature for up to three days in bitter cold before the battery died.

In its advice to owners, Tesla recommends using the “scheduled departure” feature on their car before leaving home in the cold. This warns the car to precondition its battery for best performance in the cold before leaving. It will also preheat the cabin while the vehicle is still charging, so the cabin is toasty when you get in.

Recurrent also suggests that drivers store their car plugged in if possible. “That way, the car can pull energy from the wall to keep warm, rather than using the battery. Otherwise, you may return to a lower battery capacity than expected.”

Drivers should also turn down regenerative braking on icy roads, giving them more brake pedal feel for the gradual braking needed in frozen conditions.

This Problem Will Shrink As EVs Grow More Common

America’s automakers and some state governments are planning for a future where most Americans drive electric cars. But it won’t be apocalyptic every time it snows.

Americans got used to the finicky nature of gasoline engines in the cold, investing in engine warmers in extreme climates and filling the tank more often in winter, so automatically we barely notice the change.

The New York Times notes, “Some of the countries with the highest usage of electric vehicles are also among the coldest.”

Norway has the world’s highest percentage of EVs. There, “drivers are accustomed to taking steps, such as preheating the car ahead of a drive, to increase efficiency even in cold weather,” said Lars Godbolt, an adviser of the Norwegian Electric Vehicle Association.

The country also has a more robust network of charging stations, making the slower charging times of cold weather months less of an issue.

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