Recent studies into the efficiency of electric cars have confirmed electric car owners’ suspicions that extreme temperatures drastically reduce car performance.
A recent AAA study found that cold temperatures can reduce the battery life of an electric car by up to 40 percent. It was also noted that once the interior heaters are used, the performance can drop further.
In hotter climates, electric car owners also find that the battery life is reduced, and although the damage is not permanent, the realisation of extreme temperature interference is making electric cars unfeasible in many populated areas.
Greg Brannon, AAA’s director of automotive engineering, said the importance of understanding the limitations in extreme climates can help drivers prepare. Brannon explained that by preparing, they are less likely to get stuck in a blizzard when the battery life runs out.
In the study, the 2018 models tested were the BMW i3s, Chevrolet Bolt, Nissan Leaf, Volkswagen e-Golf and the 2017 Tesla Model S 75D. The AAA study found that each car had a minimum range of 100 miles per charge, but that it significantly dropped in severe temperatures.
Using a dynamometer to measure the cars running at 20 and 95 degrees, the researchers then compared the cars’ performance under normal circumstances in temperatures set at 75 Fahrenheit. A 12 percent drop in battery life occurred in the cars driving in 20 degree temperatures. Battery life dropped to 41 percent when the interior heating was used.
Cars driving in 95 degree heat also experience a drop in battery life to 4 percent. Again, if interior cooling is used, the battery life reduced to 17 percent.
Tesla responded to the study, suggesting that the data only showed a 1 percent drop at 95 degrees, however, Tesla refused to release cold-weather data to confirm the claim.
The team at AAA disagreed, stating that the study was conducted within the procedures and guidelines designed by the auto engineering trade group SAE.
To minimize the drop in battery life caused by severe temperatures, AAA advises electric car owners to warm their vehicles up while they are still plugged in and to reduce travel during periods of hot and cold weather.