Icy temperatures cut electric vehicle range nearly in half
New research from AAA reveals that when the mercury dips to 20°F (-7°C) and the HVAC system is used to heat the inside of the vehicle, the average driving range of an electric vehicle is decreased by 41%. This means that for every 100 mi (161 km) of combined urban/highway driving, the range at 20°F would be reduced to 59 mi (95 km). When colder temperatures hit, AAA urges electric vehicle owners to be aware of a reduction in range and the need to charge more often to minimize the chance of being stranded by a dead battery.
“The appeal of electric vehicles continues to grow since a greater variety of designs and options with increased range have come onto the market,” said Greg Brannon, AAA’s Director of Automotive Engineering and Industry Relations. “As long as drivers understand that there are limitations when operating electric vehicles in more extreme climates, they are less likely to be caught off guard by an unexpected drop in driving range.”
Cold weather, however, is not the only factor that can influence driving range. AAA’s research also found that when outside temperatures heat up to 95°F (35°C) and air conditioning is used inside the vehicle, driving range decreases by 17%. Extreme temperatures certainly play a role in diminishing driving range, but the use of HVAC in these conditions—particularly the heat—has by far the greatest effect. Additionally, an electric vehicle with a compromised driving range will require charging more often, which increases the cost to operate the vehicle. For instance, AAA’s study found that the use of heat when it’s 20°F (-6°C) outside adds almost $25 for every 1000 mi (1609 km) when compared to the cost of combined urban and highway driving at 75°F (24°C).
AAA tested five electric vehicles, all with a minimum EPA estimated driving range of 100 mi (160 km), in partnership with the Automotive Club of Southern California’s Automotive Research Center. Real-world driving conditions were simulated using a dynamometer 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, with and without HVAC, were compared to those of driving with an outside temperature of 75°F.
Electric vehicle owners can take certain precautions during colder and hotter times of year to help offset potential reductions in driving range. AAA recommends that drivers plan ahead and be aware of weather conditions before heading out, allowing time for more frequent stops for charging as well as to identify the location of charging stations. Drivers should also make time to preheat 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. Finally, if possible, drivers should park the vehicle in a garage to help stabilize cabin temperature.