Geotab: Fast Charging and Heat Are Main Drivers of EV Battery Wear
A study by telematics firm Geotab finds EV batteries lose about 2.3% of capacity per year on average. Frequent DC fast charging and hot climates speed up the decline.
Electric vehicle batteries gradually lose capacity, and the pace depends on charging habits and temperature. That is the finding of an April 2026 study by Geotab, a company that provides fleet tracking and management services. Degradation can affect a car's driving range, performance and later resale value.
About the study
Geotab has published studies on EV battery degradation since 2020. The latest one analyzed more than 22,700 EVs across 21 models. The data comes from real-world telematics, meaning information taken directly from the vehicles. Because it is aggregated and averaged, an individual car's battery may wear faster or slower.
Even a high-use EV battery keeps nearly 82% of its original capacity after eight years on average. The average annual degradation rate is about 2.3%.
Fast charging
One of the main factors is DC fast charging (DCFC). It typically brings a battery to about 80% in 20 minutes to an hour. The study found that vehicles using fast charging in 12% or more of their sessions degraded by 2.5% a year, versus 1.5% for those using it in fewer than 12% of sessions.
Charging power matters too. Cars charged often (over 12% of sessions) at high power (over 40% of sessions above 100 kW) degraded by about 3% a year. High-frequency, low-power charging produced 2.2%, and low-frequency charging 1.5%.
Heat
Heat increases chemical activity and stress inside battery cells, though battery management systems help regulate temperature. EVs in hotter climates (more than 35% of days at 77°F, or 25°C, or above) degraded 0.4 percentage points faster per year than those in milder conditions. Geotab calls this a moderate effect and notes its dataset does not cover colder climates.
Geotab stresses that degradation is inevitable, but avoiding the conditions that worsen it can help owners get more from their batteries.
