Author: Jack
POSTED ON 11 Feb 2019

How Does Extreme Weather Effect EV’s Range?

With Canada and the Midwest having experienced a polar vortex which caused temperatures to drop well below -40°F, an interesting study was conducted by AAA to see how extremes in temperatures would effect the efficiency of electric vehicles and their range.

The study was conducted with the help of the Automotive Club of Southern California Automotive Research Center and used a 2018 BMW i3, 2018 Chevy Bolt, 2018 Nissan Leaf, 2017 Tesla Model S 75D, and a 2017 Volkswagen e-Golf  to get a decent representation of various price levels and technology.  The cars ran a driving-simulation in a controlled laboratory setting which mimicked conditions experienced when temperatures reach 20, 75, and 95 degrees Fahrenheit.

The results concluded that when you are attempting to heat your car up from below freezing temperatures, the toll caused by using the HVAC has a much bigger impact on range than the efficiency of the battery packs themselves. Ditto for when you’re trying to cool off in extremely high temperatures, although the diminish isn’t as severe. On average, there was a 41% decrease in range at 20°F and a 17% decrease in range at 95°F.

The BMW i3 saw the biggest reduction in range loosing 50% in freezing condition and 21% in hot conditions. The Nissan Leaf on the other hand lost 31% in freezing condition and 11% of range in hot conditions. According to AAA’s report, the lithium-ion batteries at low temperatures are less efficient due to increased heat generated as diffusion, conductivity and reaction rates decrease causing an increase in voltage perturbation. At Elevated temperatures, liquid cooling is required to help keep the batteries at an acceptable temperature instead of propelling the car.

In a nutshell, climates like California do suit the EV more than places that see a more extreme swing in temperatures. Although the drop in range may seem huge, the drop will more than likely not stop you from being able to commute from home to the office.

If you would like to read all of the 66 pages of the AAA report, you can view the report here at the AAA’s website.