It's no secret that cold weather can reduce the effectiveness of a battery, regardless of the application. A new study by AAA confirms that electric cars are no exception to reduced range in the cold, noting that it is especially exacerbated when owners crank up the heat to keep themselves warm.
In an effort to be brand-agnostic, the AAA used five different vehicles as their test subjects:
- 2017 Tesla Model S 75D
- 2017 Volkswagen e-Golf
- 2018 Chevrolet Bolt
- 2018 BMW i3s
- 2018 Nissan Leaf
Each vehicle would be placed on a dynamometer (typically used to chart vehicle power output) in a climate controlled environment. During each battery-draining run, they altered the temperature in the room surrounding the vehicle in order to understand the effects that different climates have on range depletion.
First, the organization obtained a baseline range reading on each vehicle at 75 degrees Fahrenheit. AAA would then test the car in both 20 degree and 95 degree weather, with and without the use of the car's built-in HVAC systems.
In 20 degree weather, the average range of the car fell by 12 percent without the use of heat. When the cabin heater was flipped on, the tests showed that range dropped an astounding 41 percent.
"It would easily use double the amount of power for that 15-mile trip," Jason Hughes, a notorious member of the Tesla community known for modding his cars and refurbishing spare Tesla parts, told the Associated Press. "It's definitely an issue. If you want to go somewhere far in the cold, you're going to be using more power."
Higher temperatures unsurprisingly cut into range as well when the air conditioning is in use, finds AAA. However, the results note that the amount of range zapped by turning on the heat far outweighs the range lost when using air conditioning. When tested at 95 degrees, range only dropped 4 percent from baseline. When the AC was blowing cool air, the range feel by around 17 percent.
Tesla in particular has been under fire as of late due to its best-selling premium mid-size sedan, the Model 3, not being equipped with a battery heater. Its big brothers, the Model S and Model X, are offered with the equipment as standard and use it to help to bring the cells up to temperature, improving both charging and range. To combat range lost by using a cold battery and interior heat, Tesla offers a feature called pre-conditioning which helps to warm up the cabin, and subsequently, the battery, before driving. This is extremely useful for owners who leave their cars plugged in overnight so that they are not wasting precious range while commuting.
Though the northern hemisphere is just over halfway through winter, the cold weather will still be around for several weeks. AAA recommends that as the temperatures are still cold to pre-condition the cabin while plugged, as it may help to help combat some range loss in extreme temperatures.