The state of charge (SOC) significantly affects the battery charging time for electric vehicles. Here’s how:
Impact of SOC on Charging Speed
- Faster Charging at Lower SOC: When the SOC is low, the battery can absorb energy more quickly. This is known as the “bulk charge” phase, where the battery rapidly gains charge.
- Slower Charging at Higher SOC: As the SOC increases, especially above 80%, the charging speed slows down. This is to prevent overcharging and ensure the battery’s health and safety. This phase is known as the “saturation charge” or “constant voltage charging” phase, where the voltage is kept constant to avoid damaging the battery.
How SOC Affects Charging Time
- Initial SOC: The charging time is influenced by the initial SOC when the vehicle is plugged in. Batteries charge faster when they are emptier (lower SOC) and slower when they are fuller (higher SOC).
- Battery Health: Continuous deep discharging and full charging can strain the battery, potentially shortening its lifespan. Therefore, maintaining a balance in SOC is crucial for preserving battery health.
Summary
In summary, the SOC plays a critical role in determining the rate at which an EV battery charges. Lower SOC allows for faster charging, while higher SOC results in slower charging to maintain battery integrity.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-state-of-charge-soc-affect-battery-charging-time/
