Battery age significantly influences the driving range of electric vehicles (EVs) primarily due to a phenomenon called capacity fade, where the battery’s ability to hold a charge diminishes over time. This degradation reduces the energy storage capacity, consequently lowering the maximum driving range. For example, a new EV with an initial range of 300 miles may see its range drop to 250 miles or less after regular use and aging.
How Battery Aging Affects EV Range
- Capacity Fade: Over time and with use, the lithium-ion battery’s electrodes (anode and cathode) degrade due to repeated charge and discharge cycles. This leads to structural damage such as cracking, dissolution, and changes that reduce the battery’s ion storage and release capability, diminishing the total available energy.
- Solid-Electrolyte Interface (SEI) Growth: The SEI layer forms on the battery’s anode early in its life to protect it, but as it grows continuously, it increases internal resistance and traps lithium ions, limiting the active lithium available for charge, which also decreases capacity.
- Degradation Rate: On average, EV batteries degrade at about 1.8% to 2.3% capacity loss per year according to recent studies, meaning an EV will lose a small percentage of its range annually, but still retain most of its range for over a decade.
- Battery Lifespan and Mileage: EV batteries typically last 8 to 15 years, with some data suggesting that they can last up to 20 years or more under improved degradation rates. In terms of mileage, EV batteries often last around 280,000 miles or more, with manufacturers aiming for even longer lifespan goals like Tesla’s million-mile battery.
Real-World Impact on Driving Range
- After about 50,000 miles, Tesla data shows roughly a 5% decrease in battery capacity, translating to a range reduction.
- Software updates can sometimes reduce displayed driving range by around 10% to add “grace capacity,” which helps prolong battery longevity and maintain warranty coverage, effectively managing the trade-off between range and long-term battery health.
- Even with capacity fade, EVs remain usable for many years, though with somewhat reduced range—typically enough for daily commuting and local errands once capacity drops below around 70%.
Influencing Factors
- Climate and Temperature: Higher or lower temperatures accelerate battery aging.
- Driving Habits: Aggressive driving and frequent fast charging can speed up degradation.
- Charging Cycles: How often and how batteries are charged impacts longevity.
- Manufacturer Battery Management: Battery management systems and software updates help mitigate aging effects and prolong usable capacity.
Summary
Battery age reduces an EV’s driving range due to capacity fade caused by electrode degradation and SEI growth. However, modern EV batteries degrade slowly at around 1.8–2.3% per year, allowing vehicles to retain most of their range for 10+ years and hundreds of thousands of miles. Battery management strategies, driving and charging habits, and environmental factors influence the rate of range loss. Despite some gradual reduction, EV battery longevity now rivals or exceeds internal combustion engine vehicle lifespans, making range reduction manageable over the vehicle’s lifetime.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-battery-age-influence-ev-range/
