21:44 14-01-2026

Geotab data: EV batteries degrade 2.3% yearly; fast charging accelerates wear

Modern electric-car batteries are holding steady throughout their service life, even when fast charging becomes a more frequent part of the routine. That’s the conclusion of an updated study by Geotab, which examined real-world battery health in more than 22,700 EVs across 21 brands, using several years of telematics data.

Geotab reports an average annual battery degradation rate of 2.3%. For comparison, the figure was estimated at 1.8% per year in 2024. Researchers attribute the slight increase to changing usage patterns and a growing share of sessions on high-power DC stations.

The analysis found that charging power has the biggest impact on battery wear. Vehicles frequently charged via DC at over 100 kW lost capacity faster—on average up to 3.0% per year—while AC charging or lower power levels kept degradation around 1.5% annually. In practice, the convenience of the quickest top-ups tends to come with a long-term trade-off, and blending in slower charging usually favors battery health.

Climate effects were less pronounced: in hotter regions, degradation was roughly 0.4% per year higher than in temperate areas. The study also notes that using a broad state-of-charge window doesn’t accelerate wear, provided the pack isn’t regularly taken to a full 100% or run down to nearly empty—a sensible habit that pays dividends over time.