What is State of Charge (SOC) and why is it important?

State of Charge (SOC) represents the battery's current charge level as a percentage of total capacity, similar to a fuel gauge. Accurate SOC estimation is critical for range prediction, preventing over-charge/over-discharge that damages battery, optimizing charging strategy, and managing regenerative braking limits. SOC is calculated using coulomb counting, voltage measurement, and algorithms that account for temperature, age, and operating conditions.