Recurrent, a company specializing in EV battery and range analytics, recently conducted an extensive test to find out how extreme heat affects EV range. The survey included Chevy, Ford, Hyundai, Nissan, and Tesla electric vehicles. Some of these showed up to 31% decrease in efficiency at temperatures above 100 °F. This proves how high temperatures increase their electricity consumption and reduce the range.
Charging electric vehicles is already a challenge in colder climates, but they are not good at withstanding the extreme hot weather. It has been noticed that recent heat wave across the Western and Southern United States has largely affected the range of EVs.
Recurrent, a Seattle-based EV battery and range analytics company, tested thousands of EVs in different weather conditions. They discovered that there was a significant decrease in the range of those vehicles with temperature rise. Some vehicles suffered around 31% efficiency drop when the temperature was around 100° Fahrenheit. The range recorded is way less than ideal. The survey report stated that the decrease in range was not significantly higher at cooler temperatures. The reduction percentage at 90° was on average 5%, while at 80° it was 2.8%, clearly indicating a non-linear relationship.
Recurrent utilized a combination of data extracted from the 17,000 vehicles under the company’s surveillance to accurately compute these average temperatures. The data contains 65 electric vehicles and plug-in hybrid models, including popular options like the Chevy Bolt EV, Ford F-150 Lightning, Hyundai Kona, Mustang Mach-E, Nissan Leaf, and Tesla.
The vehicle/vehicles with most or least range loss were not disclosed by the survey company. But the test indicated that the assumption that extreme heat affects EV range is true for some vehicles. Recurrent confirmed that Tesla’s range reduction was the lowest among all four vehicles. However, there was a significant difference between their actual range and the range estimated by the EPA.
Scott Case, CEO of Recurrent told in a statement, “Part of the reason for their resistance to range loss may be because of their heat pumps. They’re apparently much more efficient at cooling than standard automotive air conditioners.”
Greg Less, technical director of the University of Michigan Battery Lab, explained that, “Range decline from heat has its roots in battery chemistry. Once you’re above (104 degrees Fahrenheit) you start to have a breakdown of the passive emission layer on the anode, and that breakdown will then cause consumption of the liquid electrolyte, which will shorten the lifetime of your battery.”
Fortunately, he thinks that the excessive heat is unlikely to cause any long-term damage to EV batteries. The reason behind this is their time operation. EVs are not constantly operated under scorching temperatures of 100 degrees or higher. Moreover, EVs are equipped with a highly efficient battery cooling system. This fact indicates that there are low chances of correlation between extreme heat and EV range.
“You’re running the fan harder, you’re running the refrigerant faster. All of these things take more electricity. So that’s going to reduce the range,” Less added.
According to Greg Less, it appears that high temperatures are not the primary factor responsible for range deterioration. The reason for this is that they consume a greater amount of electricity to operate various devices during such weather conditions.
We can now only be optimistic about Greg’s theory regarding the impact of hot weather on our EVs. But at the same time we should all take all precautionary measures to prevent any damage that can possible affect their range.