“Once it gets above 85 degrees, lithium-ion batteries do see accelerated aging and degradation,” says Liz Najman, lead researcher at Recurrent, a startup that provides EV battery reports for used cars…

For EV owners, Najman recommends limiting how often you use a fast charger when it’s really hot out. “If you’re going to fast charge, try to do it when you haven’t just been on the highway for two hours and your battery is going to be a little cooler,” she says.

And if you have to leave your EV in the sun or in the heat (if you don’t have an air conditioned garage, for example), try to leave it more in the middle of the charge range; you don’t want it fully charged, or fully discharged…

Though you don’t want to leave your EV charging during a hot day, you may need to have it plugged in to kick on that internal thermal management system.