Study Reveals Electric Car Batteries Last Longer Than Expected

A recent study conducted by Geotab evaluated battery degradation rates for 22,700 electric vehicles (EVs) and vans. The findings reveal that EV batteries last longer than many consumers are led to believe. On average, these batteries experience a degradation of just two percent per year.

Battery Longevity Insights

This means that after ten years, an electric car will still hold approximately 82 percent of its original battery capacity. For example, a car with a range of 320 miles would reduce to about 262 miles after a decade.

Impact of Charging Methods

• Frequent DC rapid charging contributes to faster degradation.
• Vehicles that utilize fast charging less than one in every eight times experience only 1.5 percent degradation annually.
• Those charging more frequently with less powerful chargers see a degradation of 2.2 percent.
• Charging above 100 kW results in an average degradation of 3.0 percent per year.

A typical vehicle that travels 8,000 miles per year and charges around 250 miles between charges will undergo about 32 charging cycles. For example, taking four trips of 500 miles with one rapid charge during each journey would mean one in eight charges is rapid, affecting battery life.

Long-term Battery Care

Charging practices significantly influence battery health. While it’s commonly advised to avoid charging to 100 percent or discharging to zero, the study indicates that this has minimal impact unless the vehicle remains in these states for extended periods. Vehicles spending 80 percent of their time at such extreme levels degrade 0.5 percent faster.

Additionally, battery degradation is typically faster in hotter climates, with an estimated rise of 0.4 percent in degradation in such conditions. Parking in shaded areas can mitigate this effect.

Mileage and Usage Effects

The frequency of vehicle use also plays a role in battery longevity. For example:

• Vehicles that complete less than one charging cycle weekly (around 13,000 miles annually) experience an average degradation of 1.5 percent.
• In contrast, those that undergo charging cycles every one to two days—often seen in vans with short ranges—face a degradation of 2.3 percent annually.

Geotab, specializing in fleet management, reassures users that using EVs efficiently, with frequent long drives and fewer slow charges, helps minimize battery deterioration, preserving asset value.

Conclusion

For regular private drivers, particularly those charging overnight at home, the battery degradation rates are significantly lower. On average, a vehicle that follows these practices can retain about 90 percent of its battery capacity after ten years. This study offers a positive outlook on the longevity of electric car batteries, encouraging current and prospective EV owners about the viability of their investments.