According to recent studies, cold temperatures significantly reduce the performance of electric cars, especially when it comes to battery life.

One study by AAA suggested that cold temperatures can reduce the range of the batteries in most electric cars by over 40 percent. It was also noted that the performance can be even worse when the interior heaters are used.

However, even electric car owners who live in hot regions are not safe, because high temperatures can also reduce battery range, although to a far lesser degree.

Luckily, this damage is not permanent, and the battery range returns to normal when average temperatures return, but even if that is the case, this would make electric cars unfeasible for a large portion of the population who live in areas where the temperature is not ideal.

Electric car owners have been discovering this fact over the years as they have attempted to drive their vehicles in extreme temperatures. Electric car owners are finding that their new vehicles are much more sensitive to temperature than the ones they owned before.

Greg Brannon, AAA’s director of automotive engineering, said that it is important for drivers of electric cars to understand that these vehicles have limitations in extreme climates, this way they are less likely to get caught off guard and stuck out in the cold when their car unexpectedly runs out of battery life.

In the study, AAA tested 2018 models for the BMW i3s, Chevrolet Bolt, Nissan Leaf, Volkswagen e-Golf and the 2017 Tesla Model S 75D. Each of these cars has a minimum range of at least 100 miles per charge, but many dropped significantly when exposed to severe temperatures. The researchers used a machine called a dynamometer to test the cars.

A dynamometer is a measuring device that is built similar to a treadmill and is inside a climate-controlled cell. Once in the dynamometer, the researchers tested the cars running at different temperatures, 20 degrees, and 95 degrees, then compared how the cars performed under those circumstances with how they performed in a setting where the temperature was set at 75 degrees Fahrenheit.

The researchers found that the driving range for these vehicles fell by 12 percent while driving in 20 degree temperatures. When the interior heater in the car was used, that range dropped to an incredible 41 percent of its normal capacity.

Meanwhile, when driving in 95 degree heat, the battery life for these vehicles dropped 4 percent on average. However, these numbers got worse if air conditioning was in use. When air condition was used in 90 degree heat, the expected battery life for these cars was reduced by 17 percent.

Tesla responded to the results in a statement, suggesting that the data they collected from their customers shows that there was only a 1 percent drop at 95 degrees, but the company refused to release their data for cold weather.

AAA stands by their results, saying that the study followed test procedures drawn up by the auto engineering trade group, SAE.

To mitigate the reduction in range caused by severe temperatures, AAA suggests that electric car owners warm their vehicles up while they are still plugged in.