EV batteries are degrading more slowly than previously measured, with new research from Geotab showing an average annual degradation rate of 1.8%, down from 2.3% recorded in 2019. The telematics company’s analysis of 10,000 electric vehicles suggests EV batteries could last 20 years or more at current degradation rates.
The Geotab study, which updated the company’s 2019 battery health analysis, found significant improvements in battery durability across the EV market. According to the research, 75% of light commercial vehicles could be replaced by comparable electric models today, with potential savings of £12,000 per vehicle over its lifespan.
The study identified several factors affecting battery longevity, with temperature playing a significant role. EVs operating in hot climates showed faster degradation rates compared to those in temperate conditions, defined as fewer than five days per year above 80°F (27°C) or below 23°F (-5°C).
Charging methods also influenced battery health. The Geotab research found that frequent use of DC fast charging equipment appeared to significantly impact degradation rates, particularly in hot climates. Vehicles that primarily used slower Level 2 charging showed better battery preservation compared to those regularly using rapid charging systems.
Contrary to expectations, the study found that high-use EVs did not experience significantly greater battery degradation than lower-use vehicles when controlling for DC charging frequency. This finding suggests fleet operators can maximize vehicle utilization without accelerating battery wear, provided vehicles stay within their daily driving range.
The research highlighted differences between cooling systems, comparing 2015 model vehicles. The Tesla Model S, which uses liquid cooling, showed a 2.3% degradation rate, while the Nissan Leaf with passive air cooling recorded 4.2% degradation over the same period.
Geotab’s analysis showed that maintaining battery charge between 20% and 80% helps minimize strain on battery systems. The study also noted that many manufacturers implement buffer zones to prevent batteries from reaching extreme charge levels, which helps extend overall battery life.
The company’s EV Battery Degradation Tool, first launched in 2019, provides fleet managers with comparative data across different electric vehicle models. While the tool uses data collected through 2019, it remains a reference point for understanding battery performance trends across various manufacturers and models.
The improved degradation rates reflect ongoing advances in battery technology and thermal management systems, supporting the business case for EV adoption in commercial fleets seeking to reduce emissions.
