The issue of battery longevity has long been a major obstacle to the widespread adoption of electric vehicles. The condition of the battery determines how cost-effective and convenient it is to own a modern EV: driving range, maintenance costs, and resale value on the secondary market all come down to this component. A new large-scale study, covering more than twenty thousand vehicles from different brands, sheds light on what actually causes batteries to degrade the fastest.
Analysts examined data on 22,700 electric vehicles from 21 different brands. The findings are clear: the habit of regularly using high-power fast charging is the main catalyst for battery degradation. In recent years, the share of such charging sessions has been steadily growing, and this is already reflected in the statistics.
Charging Under Scrutiny
Whereas previously the average rate of battery capacity loss was 1.8% per year, it has now risen to 2.3%. The reason is increasingly frequent use of fast-charging stations with power output exceeding 100 kW. Over the past five years, the share of such fast charges has nearly doubled and now accounts for about a quarter of all charging events.
Electric cars are no longer just a city transport option: they are increasingly used for long-distance trips, in corporate fleets, and for intensive daily operations. This creates a demand for fast charging, but rapid charging significantly speeds up battery aging. The difference between vehicles primarily charged at fast stations and those relying on slower charging methods is quite significant.
Speed versus longevity
Drivers who regularly use high-powered charging stations see battery degradation rates of up to 3% per year. In comparison, owners who stick to slow AC charging lose only about 1.5% capacity annually. At first glance, that difference may seem minor, but over several years it can translate into tens of kilometers of lost range on a single charge.
SOH (State of Health) is the key indicator of a battery’s condition. For instance, if a new 60 kWh battery loses 20% of its capacity over time, the owner actually has only 48 kWh available. This directly affects driving range and convenience.
Climate and driving style
Charging is not the only factor that impacts battery health. Hot climates also accelerate battery wear: in regions with high temperatures, batteries lose about 0.4% more capacity per year than those in temperate zones. Intensive use is another risk factor. Vehicles that are used more frequently and for longer durations show an additional 0.8% annual decrease in capacity.
However, the study debunks the myth that charging to 100% daily or discharging to zero is critically harmful. Significant impact is only observed when the battery is regularly kept at extreme charge levels—either nearly fully discharged or constantly at maximum charge.
Durability of modern batteries
Despite the risks, modern batteries show impressive resilience. Most last longer than the average vehicle ownership period. This is especially evident in corporate fleets, where cars rack up high mileage, yet rarely need battery replacement before the vehicle itself is retired.
Experts emphasize that a charging strategy is key to prolonging battery life. Choosing between charging speed and battery longevity is not just about convenience—it’s a crucial factor for long-term savings. When a replacement battery can cost about a third of the price of a new electric vehicle, this choice becomes critical.
In case you didn’t know, Geotab is an international company specializing in telematics solutions for fleets and transportation data analysis. It has operated for over 20 years, serving millions of connected vehicles worldwide and providing analytics reports to optimize fleet management and increase efficiency.
