Avoidable Causes of EV Battery Degradation: Are They Worth Addressing?
Research by Geotab reveals critical insights regarding the avoidable causes of electric vehicle (EV) battery degradation. It emphasizes that high-voltage fast charging significantly accelerates battery aging and cell degradation. This article delves into the patterns of battery degradation based on various charging methods.
A Study on EV Battery Degradation
The study analyzed over 22,700 electric vehicles across 21 different models. It determined that fast chargers, especially those delivering over 100 kW of power, contribute notably to battery degradation. In contrast, Level 2 and less powerful chargers result in half the degradation rate.
Impact of Charging Frequency
Frequency of high-power charging plays a crucial role in battery lifespan. EVs that utilized high-power chargers for over 12% of their charging sessions faced a 2.5% annual degradation rate. Meanwhile, those that used fast chargers less frequently experienced a degradation rate of only 1.5%.
Overall Degradation Rates
- Average EV battery degradation: 2.3% per year
- Multi-purpose vehicles and vans: 2.7% yearly degradation
- Light cars: 2% yearly degradation
Notably, many batteries stabilize at a 1.4% annual average after an initial sharp decline in capacity during the first couple of years.
Fast Charging vs. Battery Health
Fast charging undeniably affects battery longevity. Regardless of the chemistry—be it Lithium Iron Phosphate (LFP) or Nickel Manganese Cobalt (NMC)—batteries can experience lithium plating if charged too quickly. This phenomenon occurs when ions build up on the battery’s positive electrode, reducing the ions available for discharge.
Temperature Considerations
Extreme temperatures also play a detrimental role in battery performance. EVs operated in warmer climates, above 77 degrees Fahrenheit, experience a degradation rate of 0.4% faster than those in cooler conditions. Similarly, charging under freezing temperatures can cause permanent damage.
Best Practices for Battery Maintenance
To enhance battery lifespan, consider the following practices:
- Avoid frequent fast charging; use it sparingly.
- Charge slowly, especially in extreme temperatures.
- Utilize battery preconditioning for optimal performance.
Interestingly, it’s unnecessary to obsess over battery charge levels. EVs can tolerate occasional full drains or charges above 80%. Degradation significantly increases only when battery levels consistently remain below 20% or above 80%.
Conclusion
Understanding the avoidable causes of EV battery degradation is crucial for any electric vehicle owner. While fast charging offers convenience, moderation is key. Modern EVs are equipped with intelligent battery management systems, ensuring that occasional high-power charging won’t drastically impact battery life. However, regular reliance on fast charging can lead to accelerated capacity loss.
