In general, higher temperatures improve the rate at which you can charge or discharge a battery. As a result, a battery’s total energy or run time at a given power rating will tend to improve when, say, you’re on vacation in Phoenix. However, says Yet-Ming Chiang, Kyocera Professor of Ceramics in the Department of Materials Science and Engineering, the battery’s number of recharges and its total time in service decreases if you linger too long in hot climes.

Chiang, who has developed breakthrough materials to enable new technologies such as stable, high-power, rechargeable batteries and novel electrochemical actuators, says lower temperatures make batteries charge and discharge more sluggishly, but tend to extend their cycle and calendar life since internal chemical degradation reactions are also slowed down at the same time.

“At sufficiently low temperatures, the liquid electrolyte may freeze and the battery will stop working altogether,” Chiang says. “So batteries in general are like Goldilocks—they like it not too cold and not too hot.”

Batteries that need to operate in unusually harsh environments can be engineered accordingly. For example, lithium-ion batteries’ electrolytes can be optimized to improve their conductivity at low temperatures, and if high temperature use is important, the electrolyte’s boiling point can be raised, Chiang says. – Deborah Halber