We’ve Been Studying EV Batteries All Wrong: Study Suggests Much Longer Lifespan

Dec. 13, 2024

A new Stanford study has suggested that average driving habits, such as sharp turns and frequent stops, may cause EV batteries to last up to 40% longer than originally thought.

Ratchet+Wrench Staff Reporters

675bcb3e003475e27a8c3080 Driving A Tesla

A new study from the SLAC-Stanford Battery Center has suggested that average driving habits may actually result in EV batteries lasting up to 40% longer than originally thought, reports Electrek.

While battery scientists typically discharge and recharge new designs at a constant rate, this method is not reflective of how they’re used in real-life driving situations, the study published in Nature Energy this month argued.

Instead, the Stanford researchers utilized four different EV discharge profiles, representing a range from the traditional constant discharge, to ones based on real-world driving data that are more diverse. For over two years, these profiles were tested on 92 commercial lithium-ion batteries.

What the researchers discovered was that the closer a profile resembled real-life driving habits, the longer the battery’s lifespan was. To understand why that is, an algorithm trained on collected data was used. It showed that the dynamic driving behaviors of the average driver actually slow down battery degradation.

For years, researchers have assumed that acceleration in EVs will speed up battery degradation. But the Stanford study showed that short, sharp turns actually have the opposite effect: they slow down battery degradation.

As Alexis Geslin—one of three lead authors of the study—noted, while cycle aging may be more important than time-induced aging in commercial vehicles that are typically under constant use, this study suggests that time-induced aging is more relevant to consumer EVs.

“We’ve not been testing EV batteries the right way,” said Simona Onori, senior author and an associate professor of energy science and engineering at the Stanford Doerr School of Sustainability. “To our surprise, real driving with frequent acceleration, braking that charges the batteries a bit, stopping to pop into a store, and letting the batteries rest for hours at a time helps batteries last longer than we had thought based on industry-standard lab tests.”