Electric Car for a Cold Climate | Driving Range

Buying an Electric Car for a Cold Climate? Double Down on Range.

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It’s no secret that electric vehicles lose range in cold weather. But how much decline should owners expect? A Consumer Reports experiment using two electric cars shows how much severely cold temperatures can affect their range.

Car shoppers who live in a cold climate who are considering an EV must buy more range than they may have expected, says Jake Fisher, senior director of auto testing at Consumer Reports. They should make sure the car gets twice their typical daily (warm-weather) needs, Fisher says.

“Typically, we warn new-car shoppers not to buy more vehicle than they need, whether that’s seats, cargo room, or towing capacity,” Fisher says. “But in this case, EV buyers who drive in colder climates should strongly consider getting a car with a range about double what their daily driving needs are, so they’re not left stranded in a cold snap.”

Range has always been a key consideration for EV shoppers, and experts expect more shoppers to get on the EV bandwagon—sales are expected to increase sixfold in the U.S. by 2025. There will be several new entries to choose from, with some available as soon as this year, from the less expensive Hyundai Kona EV to the luxury Jaguar I-Pace SUV. So testing like CR’s will be crucial for owners to understand what they’re getting into, Fisher says.

That means owners who drive 40 miles each way to work (for a total of 80 miles per day) should make sure their EV is estimated to get at least 160 miles of range unless they can reliably charge while they’re at work, he says.

For our experiment, we drove our Tesla Model 3 and our Nissan Leaf, simulating a day of driving with multiple trips. We conducted our experiment during the recent cold snap in late January, when temperatures at our test track in Connecticut dropped to 0° F to 10° F. We chose the two EVs because they’re among the two most widely sold in the U.S. and we have them in our fleet. (See results and advice below.)

What Owners Should Do

Once the temperature hits the freezing mark or below, the demands on the battery increase. There isn’t really a hard and fast number where battery performance is affected, but in general, as it gets colder, the voltage and the power output decline for an EV battery, says Sam Abuelsamid, senior analyst at automotive research and consulting firm Navigant.

Where it drops off depends in part on the battery’s chemistry and construction, although the decline is more pronounced at temperatures below 0° F, he says. But even moderately cold temperatures mean higher electrical loads to run heaters and window defoggers—all draw from the battery and reduce range.

To best combat those effects and get the most range, keep the car in a garage and plugged in until you’re ready to leave, Abuelsamid says. “It takes less energy to maintain a temperature than to raise it, so this can make a significant difference in range.”

Most EVs have cabin preconditioning that lets owners set a departure time and desired temperature. The feature turns on the climate control and warms the cabin ahead of departure—but with the car plugged in, it will use energy from the outlet, not the EV’s battery.

In the Model 3 owner’s manual, Tesla suggests owners warm up their battery to unlock as much range as possible. The manual notes that in cold weather, some of the stored battery energy might not be available until the battery warms up. Indeed, the Model 3 displayed a notification to that effect during our drives for this experiment. If the Model 3 is plugged in, you can heat your battery using wall power by turning on climate control using the mobile app, the manual notes.

In addition, Abuelsamid says, drivers should take advantage of heated seats and steering wheel, if available. That direct heat from the seat and wheel will warm you faster, and more effectively, than waiting for the air in the cabin to warm up.

What We Did

The CR experiment was designed to simulate a typical daily routine consisting of multiple drives—such as running errands. In this test, we put the EVs through three trips, each about 21 miles. (The cars traveled a total of 64 miles each.) After each of the first two legs, the cars were parked outside for an hour so that the cabin temperature would drop and the cars would have to reheat the cabin for each subsequent leg.

What We Found

• The Nissan Leaf (with its base 40 kWh battery; a longer range version is set to go on sale later this year, Nissan has said) has an Environmental Protection Agency-estimated 151-mile range. At the end of our 64-mile drive, the predicted range left was only 10 miles. Using the advertised range, the car should have traveled 141 miles before it was left with only 10. That’s more than double the anticipated loss in range.

• The Tesla Model 3 has an EPA-estimated 310-mile range. At the end of that same 64 mile drive, it indicated there were 189 miles of predicted range. Put another way, the Model 3 used 121 miles worth of range in only 64 miles. That’s almost double the anticipated loss.

The vehicles’ range displays acknowledged that they wouldn’t be going as far as their EPA estimates. The Tesla Model 3 showed a predicted range of 293 and the Leaf showed 126, less than on a warm day. However, our tests showed that even those reduced estimates were still too optimistic.

Tesla told CR that the Model 3 started off with a less-than-normal charge because of how the Model 3’s computer evaluates the conditions outside. Tesla’s Trip Planner app uses the ambient temperature at the beginning of the trip to predict temperature along the route, based on elevation along the route (temperature typically decreases when you go up in elevation), the company told CR in an email.

EV Batteries and Cold Weather

It’s important to note that EV batteries lose range not because of how the cold weather affects the physical battery but because of the added power demands that come from operating the car in cold weather.

“When it comes to range reductions, this is largely a factor of increased electrical loads on the battery,” says Navigant’s Abuelsamid. In a typical gas-powered car, the engine generates a lot of heat, which is then used to warm the cabin. An EV doesn’t have an engine, and so must rely on other devices to produce that hot air—“and those are a direct drain on the battery,” he says. The colder it is, the more energy is needed to keep the cabin at a comfortable temperature.

“Unfortunately, cold temperatures will always have a negative impact on range,” Abuelsamid says. That plays out in all sorts of way. “Breathing means condensation on cold glass, which requires use of electric defoggers. Longer nights mean more use of headlights. And cold tires, snow, and slush will increase rolling resistance, all of which will reduce range.”

Jeff Wandell, Nissan’s EV communications manager, said in an email response to CR questions that “driving conditions, driving style, and climate extremes all have an effect on battery performance and range. This is common across the automotive industry, and new technology is continuously being developed to minimize these effects.”

Tesla, in response to questions from CR about the Model 3’s results, said increased energy usage during very cold weather reduces range, and not the cold weather on its own. Still, the automaker says that on longer road trips it has not seen declines in range as big as what CR found. But it said a series of short trips would create more drain on the battery.

This is because the automatic climate control will use more power to get the cabin to its desired temperature quickly, which happens at the beginning of the trip, Tesla said in an email to CR. Once the cabin reaches the desired temperature, the draw from the heater normalizes, and the impact on the battery evens out as the car drives farther.

A study released by AAA last week found much the same as CR’s testing: When the mercury dips to 20° F and the heating system is used to warm the inside of the vehicle, the average driving range for EVs is decreased by 41 percent.

CR’s tests were done in the daytime and included a mix of highway and secondary roads. If the weather had been worse—say, at night or in a snowstorm—our range could have been further reduced.

Abuelsamid notes that traditional gas-powered cars also get reduced fuel efficiency for the exact same reasons. “Sadly, no matter how sophisticated your software is, Mother Nature and physics will always win out in the end.”

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