Frequent charging of batteries, especially lithium-ion types used in electric vehicles (EVs) and similar applications, to a high state of charge (SoC), such as close to 100%, has several detrimental long-term effects on battery health:
- Accelerated Capacity Degradation: Charging a battery continuously to 100% increases chemical and mechanical stresses inside the cells, which accelerates capacity loss over time. This reduces the battery’s ability to hold charge and shortens its overall lifespan.
- Faster Range Loss in EVs: In EV batteries, frequent high SoC charging combined with high voltage exposure is known to speed up degradation, which translates to more rapid loss of driving range.
- Thermal and Chemical Stress: High SoC levels contribute to elevated temperature and voltage conditions inside the battery, promoting breakdown of electrode materials and electrolyte degradation that harm the battery structurally and chemically.
- Reduced Cycle Life: Batteries cycled between narrower SoC windows (e.g., 20%-80%) last significantly longer than those regularly charged to full capacity, which experience greater capacity fade per cycle. For example, cycling between 75% and 25% SoC delivers more total usable energy and longer lifespan than full charges and discharges.
- Risk of Overcharging Damage: Although modern battery management systems prevent true overcharging, maintaining SoC too close to 100% increases the risk of heat generation and potential safety hazards. Overcharging can cause battery swelling, electrolyte breakdown, and in extreme cases, thermal runaway leading to fire or explosion.
In summary, maintaining a frequent high SoC charging habit gradually reduces battery longevity and performance. Optimally, to prolong battery life, it is advised to avoid regularly charging to full (100%) and instead keep the battery charge typically between 20% and 80% SoC. This approach minimizes degradation mechanisms, extends cycle life, and preserves battery capacity over time.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/what-are-the-long-term-effects-of-frequent-high-soc-charging-on-battery-health/
