Battery Degradation
Battery degradation is the gradual loss of a battery's ability to store energy and deliver power. It happens through two overlapping processes: calendar aging while the battery exists, and cycle aging as it is charged and discharged.
Why it matters
As usable capacity declines, the vehicle may offer less driving range at the same displayed state of charge. The rate is not fixed: battery chemistry, temperature, time spent at very high or very low charge, charging behavior, and vehicle use can all influence it. A single odometer reading therefore cannot describe battery health on its own.
Modern EVs use thermal management, operating limits, and software controls to slow harmful conditions. Owners can also follow the manufacturer's storage and charging guidance. For the mechanisms, measurements, and practical battery-care guidance, see Battery Degradation and Protecting the EV Battery.