The pace of EV battery performance decline varies depending on how often drivers use fast charging, the charging power and exposure to high temperatures, a report showed. Average annual degradation is about 2.3 percent, but the gap widens depending on charging methods and climate conditions, meaning drivers need to pay attention to charging habits to manage battery life, IT outlet Engadget reported on Oct. 26.

Vehicle management services company Geotab examined battery degradation patterns using real-world data from more than 22,700 vehicles across 21 EV models, in an analysis released in April 2026. The study used telematics information collected from vehicles.

The survey put average annual battery degradation at 2.3 percent. Geotab found that even EVs with high mileage retain about 82 percent of their initial battery capacity after 8 years of use. But that figure is an average, and battery life for individual vehicles can vary depending on battery type, operating environment and charging habits.

Direct current (DC) fast charging was cited as a key factor affecting battery degradation. Vehicles in which fast charging accounted for at least 12 percent of all charging had an annual degradation rate of 2.5 percent. Vehicles with less than 12 percent fast charging showed 1.5 percent.

Charging power, not just the number of charging sessions, also mattered. Vehicles that used fast charging frequently and conducted more than 40 percent of those sessions at outputs above 100 kW had an annual degradation rate of about 3 percent. Vehicles with a high share of fast charging but charging at relatively lower outputs showed 2.2 percent, while vehicles with a low share of fast charging recorded 1.5 percent.

That suggests vehicles that frequently use high-power fast charging may see battery capacity fall faster. But the relationship between charging power and degradation can vary depending on several conditions, including the battery management system and vehicle-specific design.

Temperature was also confirmed as a factor affecting battery life. Geotab explained that high temperatures can speed up chemical reactions inside batteries and increase stress on cells. EVs have management systems that regulate battery temperature, but they cannot fully eliminate the impact of hot environments.

EVs in hot regions, where days with temperatures above 77 degrees Fahrenheit (about 25 degrees Celsius) exceed 35 percent of the year, had annual degradation rates 0.4 percentage points higher than vehicles in milder regions. Geotab assessed that as a moderate impact. The analysis also had a limitation in that climate conditions in cold regions were not sufficiently reflected.

The analysis suggests that even if EV battery performance decline is inevitable, there is room to slow the pace depending on how the vehicles are used. Fast charging is useful for reducing charging time, but its impact on battery degradation can vary depending on frequency and power. Hot environments are also a factor to consider in long-term battery management.

EV drivers need to consider not only charging convenience but also their reliance on fast charging, charging power and the temperatures in the areas where they drive. The findings may not apply equally to all EVs, so in practice it is important to also review manufacturers' recommended charging guidance and vehicle-specific battery management functions.