Rechargeable lithium-ion batteries power most electric vehicles (EVs). Built to last or exceed an EV’s functional lifespan, these energy-dense batteries typically boast an impressive range of 100,000 to 150,000 miles. Although all EV batteries steadily lose their ability to hold charge over time, many factors actively accelerate degradation.
This article discusses how frequent high-voltage charging, deep discharges, and extreme temperatures shorten EV battery lifespan. It also reviews Tesla, Chevy, and BMW warranties, exploring sustainable second-life initiatives for older EV batteries, such as energy storage and electrical grid backup.
Lithium-ion vs. lead-acid
EV lithium-ion traction batteries are specifically designed to drive electric motors efficiently. EVs are also equipped with 12V lead-acid accessory batteries that power electronic control units (ECUs) and low-voltage systems such as lighting, central locking, and telematics. Lithium-ion batteries, drawing supplemental energy from regenerative braking systems, keep these 12V units fully charged.
In moderate climates, EV lithium-ion batteries can last 12 to 15 years, achieving a lifetime range of 100,000 to 200,000 miles. Most EVs experience a 5% to 10% capacity loss within the first 40,000 miles. After an initial decline, they typically stabilize and retain approximately 80% to 90% of their original capacity for 100,000 miles and beyond.
Notably, Tesla’s 2022 Impact Report claims an 88% battery capacity at 200,000 miles.
Figure 1. Battery retention percentage over distance traveled for Tesla Model S/X vehicles, indicating the long-term stability of battery capacity. (Image: Tesla)
Tesla’s Model 3 Standard Range guarantees 70% capacity for 100,000 miles or eight years, while Model S and X warranties cover 150,000 miles over the same period. Similarly, Chevy (GM) offers an eight-year, 100,000-mile warranty for Bolt, Volt, and Malibu electric propulsion components. Although Hyundai provided a lifetime battery guarantee from 2012 to 2019, the warranty was subsequently adjusted to 10 years or 100,000 miles for 70% capacity maintenance. BMW and VW provide comparable 70% capacity warranties for eight years or 100,000 miles.
Minimizing EV degradation
EV battery degradation is inevitable. Over time, chemical reactions such as lithium plating and electrolyte decomposition reduce charge-holding capacity, reducing range, efficiency, and performance. Deep discharges and rapid, high-voltage charging accelerate this degradation by negatively impacting the battery’s chemical composition. Moreover, prolonged exposure to extreme temperatures can further lower battery state of health (SoH) levels below the industry-recommended 70%.
Managing depth of discharge and charging methods
Defined as the percentage of battery capacity used between charges, depth of discharge significantly impacts SoH and lifespan. Maintaining a partial or reduced depth of discharge helps prolong battery life by keeping the state of charge (SoC) within an ideal range of 20% to 80%. Frequent or sudden acceleration adversely affects SoH by increasing discharge depth and speeding battery depletion.
For example, Hyundai’s Kia Soul Booster can withstand 1,000 charge cycles when depleted completely to 0% and then recharged to full capacity. This lifespan increases to 5,000 cycles at 50% discharge up to 8,000 cycles with only a 20% discharge before recharging. Many battery management systems (BMS) are designed to automatically maintain optimized power levels for SoH and SoC.
Figure 2. Cross-sectional diagram of an EV showing the placement of EV batteries under the vehicle’s floor. (Image: LaserAx)
Rapid and high-voltage charging methods, especially DC fast charging, accelerate battery degradation by inducing physical stress and generating excessive heat. To preserve battery SoH, regular Level 2 (220V) charging is recommended as the default option, with DC fast-charging stations used sparingly.
Mitigating extreme temperatures
Both extreme cold and heat significantly accelerate EV battery degradation. Operating an EV in high temperatures is particularly damaging as it intensifies adverse chemical reactions within the battery. To maintain lithium-ion battery packs within an optimal temperature range of 50°F to 85°F, many EVs incorporate:
- Thermal management: A sophisticated sensor network monitors fluctuating temperatures and performs real-time thermal adjustments.
- Liquid cooling: Common in modern EVs, liquid cooling systems effectively regulate battery temperature, even in extreme heat.
- Battery heating: In cold climates, battery heaters prevent permanent damage by stopping electrolytes from freezing.
- Dynamic charge management: Frigid temperatures negatively impact charging efficiency. Battery management systems dynamically adjust the charging process, ensuring a steady and efficient charge rate in low temperatures.
Second life, not end of life
Though no longer efficient for driving electric motors, aging EV batteries are finding a sustainable second life in energy storage and electrical grid backup. Nissan, for example, repurposes old LEAF batteries to power streetlights, while GM uses spent batteries as backup power sources for Michigan data centers. Older EV batteries also function as storage units for renewable energy, bolstering grid resilience and providing emergency backup power.
Solid-state batteries could eventually offer higher energy density, lower costs, and more efficient recycling methods. These batteries would potentially replace the liquid electrolytes found in traditional lithium-ion batteries with ceramics or other solid material — increasing storage capacity and extending driving range while reducing charging time and fire risk.
Summary
EV lithium-ion batteries can last 12 to 15 years in moderate climates and achieve a range of 100,000 to 200,000 miles. Although all EV batteries lose their ability to hold charge over time, various factors actively speed up degradation. For example, frequent high-voltage charging, deep discharges, and extreme temperatures considerably reduce EV battery longevity.
By effectively mitigating these factors with balanced charging, temperature control, and consistent, smooth acceleration, EV drivers can significantly extend battery and vehicle lifespan.
References
- Understanding EV Battery Life, SEAI
- New Study: How Long Do Electric Car Batteries Last?, Recurrent Auto
- How Long Do EV Batteries Last?, Road and Track
- How Long Does an Electric Car Battery Last?, EVConnect
- What Happens to Old Electric Car Batteries?, National Grid
- What’s Next for Batteries?, MIT Technology Review
- EV A to Z Encyclopedia – 1: Understanding EV Components, Hyundai Motor Group
- 2022 Tesla Impact Report, Tesla
Filed Under: Batteries, FAQs