Excessive heat can drastically reduce a third of range in some electric vehicles

According to a recent study conducted by Seattle-based Recurrent, excessive heat can significantly reduce the range of electric vehicles (EVs). This finding aligns with previous research that showed how extreme cold also impacts EV range. Fortunately, most EVs seem to remain relatively unaffected unless the temperature reaches triple digits.

Recurrent analyzes thousands of vehicles annually to study the relationship between batteries and their range. Their latest data reveals that during extremely hot conditions, some EVs could experience a decline of nearly one-third of their stated range. Although Recurrent did not mention specific vehicle models, it noted that certain cars saw a reduction of 31 percent in their range when temperatures surpassed 100 degrees Fahrenheit (38 degrees Celsius).

Interestingly, Recurrent’s previous research from last year demonstrated a similar effect in freezing temperatures. The Ford Mustang Mach-E and the Volkswagen ID.4 experienced a decrease in range of 30 percent when temperatures dropped below 30 degrees Fahrenheit (-1 degrees Celsius). However, it’s worth noting that battery range remains relatively unaffected during less extreme temperatures.

Recurrent also pointed out that its data about triple-digit range depletion is very limited for now. “Note that the range loss at 100 degrees is based on extremely limited data, and we will update it when we have more confidence in the value,” it says in the study. CEO Scott Case explained to Automotive News that gathering such data is tough because most driving is done early in the day before triple digits are reached.

According to Greg Less from the University of Michigan Battery Lab, the decrease in range at those high temps comes down to 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,” he said.