AAA Research Lays Out How Temperature Affects EV Range

While we all know extreme temperatures influence the performance of electric vehicles, there isn’t a wealth of comprehensive studies on the matter. Hoping to impart some knowledge on the subject, the American Automobile Association released a report on Thursday that examines how climate impacts EVs.

AAA offered an abridged version in 2014, when it claimed data from its Automotive Research Center (ARC) showed battery-only driving range can be nearly 60 percent lower in extreme cold and 33 percent lower in extreme heat. However, the new study fine-tunes those numbers while exploring other avenues of how EV performance can suffer.

This time, the motor club federation rounded up electric vehicles for testing (BMW i3, Chevrolet Bolt, Nissan Leaf, Tesla Model S 75D, and Volkswagen e-Golf) and sent them to ARC in Los Angeles, CA. The study found that, on average, electric driving range decreases by 41 percent when outside temps fall to 20 degrees Fahrenheit and climate controls are switched on, versus the 75-degree benchmark. Range also diminished as the mercury rose, albeit not as aggressively. Running the A/C on a 95-degree day only resulted in a 17-percent average loss in total range.

That seems to indicate that EV battery performance has improved since 2014, as all the vehicles used in the last round of tests were from the 2017 model year or newer. But it also shows that colder climates remain a noteworthy obstacle for electric cars.

There are ways to mitigate this. Drivers can tailor their driving habits to maximize range and automakers have begun installing systems that help regulate battery temperatures. Owners can also pre-heat or cool their vehicles before taking it off the charger to reduce the burden the climate system places on the battery. However, none of these remedies come close to solving the problem entirely. Your best defense remains keeping an eye on your current charge status and holding onto the knowledge that extremely cold temperatures will have an impact.

“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,” said Greg Brannon, AAA’s director of automotive engineering and industry relations, in a statement to Automotive News — which first shared the study.

While running an EV in extremely cold weather does incur a modest increase in cost to the owner, just like with internal combustion engines, the big problem is being caught out in the elements with severely diminished range. Losing almost half of your expected driving radius when it’s below freezing is not the kind of surprise you want to get on the side of a highway. Thankfully, AAA knows that knowledge is power and is eager to spread the word.

“The research clearly shows that electric vehicles thrive in more moderate climates, except the reality is most Americans live in an area where temperature fluctuates,” said Megan McKernan, manager of the Automotive Club of Southern California’s Automotive Research Center. “Automakers are continually making advances to improve range, but with this information, drivers will be more aware of the impacts varying weather conditions can have on their electric vehicles.”

The full study goes into extreme detail, examining the individual test results of each car and dialing down some of the associated costs, as well. We recommend taking a look at it if you’re interested in purchasing an EV outside the confines of a warm-weather state, orif you’re simply curious about the science behind the data.

[Image: Electrify America]