SOC (State of Charge)
Meaning
“State of Charge (SOC) is the measurement of the remaining energy in an electric vehicle’s battery, expressed as a percentage from 0% to 100%. It serves as the digital “fuel gauge” for an EV. SOC is a critical data point for the vehicle’s Battery Management System (BMS), as it determines the optimal charging speed.
In the UK, understanding SOC is essential due to the “charging curve”: most EVs charge at their maximum rate when the SOC is low (typically between 10% and 80%). Once the battery reaches 80% SOC, the charging speed drops significantly to protect the lithium-ion cells from heat and degradation. For daily driving in the UK, manufacturers often recommend maintaining an SOC between 20% and 80% to prolong battery life and ensure peak efficiency.”
