Researchers analyzing years of EV driving data discovered how differences between individual battery cells can intensify over time.

An electric vehicle (EV) battery can reach the end of its useful life even when many of its individual cells still have substantial capacity remaining. New research shows that a small number of rapidly aging cells can shorten the lifespan of an entire battery pack, leaving a significant share of its potential energy resources unused.

Published in Nature Energy, the study analyzed batteries operating in real vehicles over more than three years. Researchers found that differences between individual cells can reduce battery lifespan, restrict power output, and become more pronounced as vehicles accumulate mileage.