Frigid Weather Decreases EV Range Dramatically, Study Finds

Credit: AAA
Electric vehicle range can be impacted drastically by extreme temperatures, according to a new study from the American Automobile Association. It’s especially true when using the car heater during frigid temps, but hot weather has an impact, too. Using either the car’s heating or A/C system can reduce range and result in the need to charge more often. Both are things drivers should keep in mind when they head out on the road in those conditions.

Extreme Temps Decrease EV Range

Here is a closer look at AAA’s numbers that show a substantial decrease in EV range, especially in cold weather when the heater is in use.

When the HVAC is not in use:

  • On average, an outside temperature of 20°F, resulted in a 12 percent decrease in driving range while an outside temperature of 95°F, resulted in a 4 percent decrease.

When the HVAC is in use:

  • On average, an outside temperature of 20°F, resulted in a 41 percent decrease. While an outside temperature of 95°F, resulted in a 17 percent decrease.

Impact on Charging

In addition to range considerations, there is a cost factor to think about as well. An electric vehicle with a compromised driving range will have to be charged more often, increasing vehicle operation costs.

Depending on outside temperature, AAA researchers found that HVAC use resulted in a significant monetary cost increase.

  • On average, an outside temperature of 20°F, resulted in a cost increase equal to an additional $24.27 for every 1000 miles while an outside temperature of 95°F, resulted cost increase equal to an additional $7.94 for every 1000 miles.

AAA Tips for EV Drivers

According to the AAA study, in 2017, U.S. sales of electric vehicles alone were up 20 percent over the previous year. There are things EV drivers can to do offset or be prepared for reduced range caused by hot or cold weather conditions. AAA recommends drivers:

  • Plan ahead. When drivers are aware of the weather conditions before heading out, they can plan for more frequent stops for charging as well as identify the location of charging stations. Drivers can access these locations through AAA’s Mobile app or TripTik Planner.
  • Make time to “pre-heat” or cool down the inside of the vehicle while still connected to the charger. This will reduce the demand on the vehicle’s battery to regulate cabin temperature at the onset of driving.
  • If possible, park the vehicle in a garage to help stabilize cabin temperature.
  • While electric vehicle range performs best in areas with warm weather year-round such as Florida, Hawaii and California, drivers in other parts of the country shouldn’t be discouraged. Owning an electric vehicle in these regions just requires some additional planning.

About the Study

AAA tested five electric vehicles, all with a minimum EPA estimated driving range of 100 miles, in partnership with the Automotive Club of Southern California’s Automotive Research Center. Real-world driving conditions were simulated using a dynamometer, essentially a treadmill for cars, in a closed testing cell where ambient temperature could be closely controlled. To determine the effects on driving range, scenarios for cold and hot weather conditions – both when using HVAC and not – were compared to those of driving with an outside temperature of 75°F.

You can read the full report here.

Photo Credit: AAA
Larry Hudson
If you run both the heater and AC, in cold, humid weather, to prevent fogging on the inside of your windows, range will be even less. And you may well need your lights and wipers at such time. My experience has been that under wet cold conditions range is reduced by more than 60 percent.