Introduction
A new Geotab study released this month sheds light on a long-standing question for electric-vehicle (EV) owners: how fast do batteries lose capacity, and what can drivers do to slow that loss? By tracking 21 different EV models across North America, the research shows that the speed and frequency of charging play a decisive role in battery health. The findings give both fleet managers and individual drivers a clearer roadmap for extending battery life and cutting future replacement costs.
At a Glance
- Fast-charging users lose 2.5 % of battery capacity each year, double the rate for slower chargers.
- Level 2 charging users lose 2.3 % annually, a modest decline.
- The study finds that batteries now last twice as long for vehicles that rarely use fast charging.
- Why it matters: Knowing how charging habits affect degradation can save owners thousands of dollars and help fleets reduce long-term risk.
Battery Degradation Findings
The survey measured the annual loss in initial capacity for 21 EV models. The key numbers are:
| Charging Mode | Annual Capacity Loss |
|---|---|
| Fast-charging >12 % of cycles | 2.5 % |
| Fast-charging ≤12 % of cycles | 2.3 % |
| Level 2 charging | 2.3 % |
Overall, the average loss was 2.3 % per year, an increase from 1.8 % two years earlier. The jump reflects a growing share of fast-charging use among the expanding EV population. While the firm notes that its test pool is larger and older, it attributes the higher degradation rate primarily to increased fast-charging frequency.
> “Our latest data shows that batteries are still lasting well beyond the replacement cycles most fleets plan for,” said Charlotte Argue, Geotab’s Senior Manager of Sustainable Mobility. “What has changed is that charging behavior now plays a much bigger role in how quickly batteries age, giving operators an opportunity to manage long-term risk through smart charging strategies.”
Context from the Past
For decades, internal-combustion-engine (ICE) drivers have boasted that their cars can travel over 200,000 miles with only routine oil changes. EV drivers, meanwhile, have worried about how quickly a battery will fade. This study suggests that, with proper charging habits, EV batteries can outlast the typical 13-year lifespan of a U.S. vehicle, according to S&P Global.
Charging Speed Impact
Fast-charging stations, delivering power above 100 kW, are common at highway rest stops and convenience stores. The research shows that vehicles using these stations more than 12 % of their charging cycles experience a twice-as-fast rate of degradation compared to those that rarely use them. This aligns with the physics of battery chemistry: higher currents generate more heat and stress, accelerating chemical wear.
In contrast, Level 2 chargers, which provide power below 100 kW, are associated with a modest decline in capacity. For fleets that prioritize long-term reliability, the data points to a clear advantage in limiting fast-charging use.
Fast-Charging vs. Level 2
| Feature | Fast-Charging | Level 2 |
|---|---|---|
| Typical Power | >100 kW | <100 kW |
| Ideal Use | Long highway trips | Daily or regular charging |
| Cost per kWh | 47 ¢ | 25 ¢ |
| Impact on Battery | Higher degradation | Lower degradation |
Economic Implications
Battery replacement has always been a major cost concern for EV owners. The study’s findings suggest that batteries are lasting well beyond initial expectations and likely outlast the typical 13-year life of a U.S. vehicle. This means replacement cycles are less frequent than many fleets plan for.
Charging costs also vary dramatically:
| Charger Type | Price per kWh |
|---|---|
| Level 2 public | 25 ¢ |
| DC fast public | 47 ¢ |
| Home charging | 18 ¢ |
These averages, taken between July 2024 and July 2025, show that fast-charging is more than twice as expensive as Level 2 public charging, while home charging remains the cheapest option.
Cost Breakdown
A 60-kWh battery that loses 2.3 % of capacity each year will require replacement after roughly 10 years if the vehicle is driven heavily. If the same battery is charged mostly at fast-charging stations and loses 2.5 % per year, the replacement window shrinks to about 9 years. The difference in cost can amount to several thousand dollars over a vehicle’s life.
Strategic Charging Recommendations
The study confirms that fast-charging stations are still essential for long highway trips, where a rapid charge from 10 % to 80 % can get a driver back on the road quickly. However, to preserve battery health, fleets and drivers should:
- Use fast charging sparingly-limit it to no more than 12 % of total charging cycles.
- Prefer Level 2 chargers for regular, off-peak charging, especially in office parks, malls, and street parking.
- Leverage home charging whenever possible, benefiting from lower costs and gentler battery stress.
- Implement smart charging strategies that balance speed with battery longevity, as highlighted by Charlotte Argue.
Smart Charging Features
Many modern EVs now include software that can delay charging until after a trip or limit the maximum state of charge. Utilizing these features can further reduce degradation, especially when combined with Level 2 charging.
Partnerships and Infrastructure
The partnership between Mercedes-Benz and Buc-ee’s, launched in 2023, exemplifies how fast-charging can be integrated into existing retail locations. While these stations offer convenience, the data suggests they should be reserved for occasional use rather than routine daily charging.
Other networks are expanding Level 2 infrastructure at malls and office parks, providing drivers with inexpensive and battery-friendly options. As the charging ecosystem matures, the balance between convenience and longevity will become a key factor in fleet planning.
Conclusion
The Geotab study provides a data-driven roadmap for extending EV battery life. By understanding how charging speed and frequency affect degradation, fleet operators and individual drivers can make informed choices that reduce replacement costs and improve vehicle reliability. As EV adoption grows, smart charging strategies will become increasingly vital for sustainable, cost-effective mobility.
