As cold weather sweeps across the United States, some electric car owners are learning a bitter truth: Freezing temperatures can stop cars in their icy tracks.
The problem crystallised this week when some Tesla owners in Chicago discovered their electric car batteries were dead He died At sub-zero temperatures. Drivers also said that some Tesla charging stations were not working, or if they were working, the stations were taking longer than usual to charge their cars.
“I've been here for over five hours at this point, and I still haven't been able to charge my car,” Tesla driver Brandon Wilburn said. He told CBS Chicago. “A charge that should take 45 minutes takes 2 hours.”
Electric vehicles, or EVs, are known to lose efficiency in cold weather, an issue that Consumer Reports investigated last year over concerns about wide differences in how different electric cars hold up in cold weather. Meanwhile, the federal government is offering a $7,500 federal tax credit, a financial carrot that helped boost electric vehicle sales to a record 1.2 million vehicles last year.
“Electric cars certainly lose some of their driving range in extreme cold,” Scott Case, co-founder and CEO of Recurrent, a battery research company, told CBS MoneyWatch.
The problem is similar to what can happen with other battery-powered devices in cold weather.
“If you go skiing with your iPhone, you may notice that the battery will burn out more quickly, so it may run out of juice in the middle of the day, where it would normally last all day,” Case noted.
Here's what you should know.
What happens to electric cars in cold weather?
Electric cars are less efficient in cold weather, with Recurrent research finding that below-freezing temperatures reduced driving range by up to 30% in 18 popular electric car models.
An electric vehicle with a range of 200 to 215 miles might only get 150 to 175 miles in the cold, Recurrent's Case said, noting that reducing mileage is often enough for most drivers. “The average person who owns an electric car drives 30 miles a day,” he said.
However, shorter range in cold weather could be an issue for some owners if their EV runs out of power miles earlier than expected, which could result in them being left searching for an available charger, or worse, being stranded in extremely cold conditions. .
Why are electric vehicles affected by cold weather?
First, the chemical and physical reactions inside an electric car battery require more time when the mercury level drops, according to Recurrent. Because cold slows down these physical processes, it reduces the power available to the electric vehicle.
Second, unlike cars powered by internal combustion engines, electric vehicles cannot utilize engine heat to warm the interior of the vehicle.
“From a range perspective, EVs tend to fare worse in cold weather due to the need to heat the cabin for comfort,” Alex Knizek, director of automotive testing and insights at Consumer Reports, told CBS MoneyWatch in an email.
EVs rely on an auxiliary heater, which Knezek noted are often “resistive heaters — much like a space heater you might use at home.” Most newer EVs also have the option to be equipped with a heat pump, which is more efficient, but also suffers when temperatures drop into the single digits or lower.
Why don't electric cars also charge in the cold?
Charging electric vehicles can take longer when it's cold. This is partly because most electric cars are designed to boost battery temperatures when the thermometer dips, Knezek said.
“This power to do this comes from the battery itself, which reduces the range,” Knezek added. “This also has an impact on charging speeds. If the battery is too cold, it will charge more slowly and may need to warm itself up before charging speeds up.”
How do EV owners cope in places like Norway and other places with cold weather?
Cold weather is no deterrent for some drivers in countries and regions with cold weather, as evidenced by Norway, where 8 out of 10 new car purchases are electric, making it the fastest country to adopt electric vehicles. Iceland and Sweden rank second and third in terms of electric vehicle adoption, according to the World Resources Institute.
Drivers in cold regions have learned tricks for working with their electric cars, such as heating the car's cabin while plugged in (see tips below).
Electric cars are “fully capable of handling winter if you know what you’re doing,” Stal Frydenlund, testing director at the Norwegian Electric Vehicle Association, told The Globe and Mail last year. “The challenge is teaching beginners how to do it.”
Will cold weather damage an electric car battery?
No, according to a recurring issue.
“If you're in a cold climate, you're more likely to have a battery that will hold up over time versus hot climates,” he said. “The thing about very cold weather is that it reduces the range on a solo trip, but it doesn't do anything for the battery in the long run.”
Can EV owners prevent battery problems when it's cold?
Yes, there are many tips recommended by Knizek from Case and Consumer Reports. They both recommend warming up your EV's cabin while the car is plugged into the charger and before you intend to take it out for a drive.
“This means that the car will use energy from the grid [charger] “For heating rather than the battery itself,” Knezek said. “You can use the vehicle's smartphone app to do this or set the departure time within the vehicle's infotainment screen.”
Next, also pre-condition the battery before using a DC fast charger – a step usually available by pointing your navigation system at a DC fast charger or a button that can trigger the process.
“This uses battery power to heat itself to the ideal temperature, allowing for better fast charging performance,” Knezek said. “Doing so costs some scale, but overall the payoff is worth it.”
Finally, lower the temperature in the cabin and drive more slowly. “Speed and aerodynamics have a huge impact on range, regardless of temperature,” he noted.
What does Tesla say about cold weather?
Tesla did not immediately return a request for comment to CBS MoneyWatch, but its website advises owners to keep the battery charge level above 20% during extreme cold weather.
The automaker also says it's normal to see an increase in energy consumption because Tesla cars use more energy to heat the battery and cabin.
“We've made several updates to improve your driving experience in freezing temperatures, including better overall thermal performance, faster supercharging, and improved cabin air conditioning,” Tesla notes on its site.
Are there other problems with electric vehicles?
Even in optimal weather, some electric cars fell as low as… 50 miles is short of advertised driving ranges, according to Consumer Reports.
And another study conducted by the advocacy and product testing organization is found Electric vehicles have about 80% fewer mechanical problems and are generally less reliable than gas-powered cars.
Case noted that Tesla vehicles in the Chicago area that experienced battery issues during this week's cold snap probably won't change anyone's mind about buying an electric car.
“Everyone who didn't want to buy one feels better about their decision because they saw the pictures from Chicago, and everyone who was going to buy an electric car has already made up their mind,” he said.
