Charging

How Cold Weather Affects Electric Cars

August 11, 2021

How Cold Weather Affects Electric Cars

Outside temperatures affect electric car batteries. In the winter months when temperatures fall below 20 degrees, electric car batteries take a major hit. A study by AAA found that if you use your electric car’s heater while driving in cold temperatures, your range can be temporarily cut by as much as 41 percent. The study of five electric vehicles by AAA also found that high temperatures can cut into battery range, but not nearly as much as the cold. Driving range returns to normal in more comfortable temperatures, say 70 to 80 degrees.

What's going on, exactly?

That means in cold weather, if you own an electric car that is rated to run 150 miles on a charge, you’ll likely only drive 88 miles before you need a charge. It will take longer to bring the vehicle’s battery up to a full charge as well. Frigid temperatures also limit an electric car’s regenerative braking function, which recovers energy that would otherwise be lost during decelerating or stopping and sends it back to the battery.

The study reported that at 20 degrees, the average driving range fell by 12 percent when the car’s cabin heater was not used. When the heater was turned on, the range dropped by 41 percent. At 95 degrees, range dropped 4 percent without use of air conditioning, and fell by 17 percent when the cabin was cooled. AAA says it followed test procedures drawn up by SAE, an auto engineering trade group.

Within the next five years, new battery technology will not require liquid inside, and they won’t be as sensitive to the cold. But for right now, what do you do when cold temperatures can substantially hamper both a battery’s performance and its ability to accept a charge?

Charging in Cold Weather

Most importantly, don’t let your battery get too low. Make sure you always have at least a 20% charge. You’ll need that reserve to warm the car both inside and to warm up the battery. While your EV is still plugged in, use that reserve of power to precondition the car before heading out.

If possible, keep your electric car in a heated garage when it is not in use to keep it out of the elements. If you are away from home, try to park in the sun to keep the car warmer. Always keep it plugged in at home to maintain a full charge. Many EVs have a “pre-conditioning” feature that is engaged by a smartphone app. This will heat both the interior and the battery while the vehicle is plugged into the charger, which will help preserve battery capacity. Use this to get your car ready for the road.

Driving in Cold Weather

Remember that speed drains the battery too. The faster you go, the more that speed sucks your charge up. Ease off the accelerator to add battery range. Plus, a car’s aerodynamic drag increases at higher speeds and requires added power to overcome. So, in cold weather, it is important to slow down and drive safely. Even with all their technology, electric cars can spin out on ice and snow just as easily as conventional vehicles.

Many electric cars have “Eco mode” that adjusts performance to preserve your battery range. In cold weather, selecting Eco mode will help extend your range. Also, may EVs have the ability to let you adjust the regenerative braking feature. If your car has this feature, set your regenerative braking to the max to send more power back to the battery under braking.

When driving in cold weather, the less you use the heater, the more range you will have. Setting the temperature lower will help sustain your range. Many electric cars have heated seats and even heated steering wheels that drain less juice than the heater. In the aforementioned AAA study, the electric vehicles tested only lost about 12 percent of range in the cold while running with their heaters switched off, compared to 41 percent with the climate control in use.

When out and about in frigid weather, it is important to have the ability to get a quick charge if needed. Make sure you know where public charging stations are located near where you live, shop and work. Remember that DC fast charging stations can charge your battery back up to 80 percent in 30 to 45 minutes, even in freezing temperatures.

Want to more about charging electric cars? Read our Definitive Guide to Charging Electric Cars.