Geotab’s analysis of real-world data from more than 22,700 electric vehicles representing 21 makes and models found average annual battery-capacity degradation of 2.3%, compared with 1.8% in its earlier analysis. The dataset reflects vehicles in use, not a laboratory test, and the average is not a guaranteed rate for any individual car.
The rise does not, by itself, mean battery hardware has become less durable. Changes in the vehicles represented and in how they are used, including charging habits and operating intensity, can shift a fleet-wide average. At a constant linear decline of 2.3% a year, a battery would retain about 81.6% of its original capacity after eight years. That calculation is an illustration, not a model-specific forecast or a warranty threshold.
Charging patterns were associated with a large difference in degradation rates. Vehicles that frequently used DC fast charging above 100 kW recorded about 3% annual degradation, compared with roughly 1.5% for vehicles relying mainly on lower-power charging. The comparison is observational. Differences in vehicle design or battery chemistry may also contribute; climate and mileage vary too, as do operating conditions.
High-power charging can generate more heat and electrochemical stress in a battery, offering a technical explanation for the observed association. Fast charging remains valuable for long-distance journeys and fleet operations. The practical consideration is to use lower-power AC or DC charging when it fits operational needs. The findings point to a potential trade-off between charging speed and long-term battery health, not a reason to avoid rapid charging altogether.
These findings matter to fleet managers and private owners as electric vehicles become more common in Spain and across Europe. Charging choices can affect long-term capacity and operating costs, with resale value also affected, although individual outcomes vary with vehicle design and use. London’s approach to street charging has also drawn attention, as detailed in this report on urban charging solutions.
Previous research from Sweden found that 8 out of 10 electric vehicles retained more than 90% of their original battery capacity after several years of use. Geotab’s figures add a further perspective: in-service battery performance depends on vehicle technology and on how each vehicle is used and charged.
As the electric-car market matures, practical knowledge about battery care will increasingly shape consumer and fleet-operator decisions about vehicle use, including resale and total cost of ownership.
