SOC stands for State of Charge, which means how much energy is left in the battery. What Does SOC Mean? The percentage displayed by the SOC indicates how much battery power we have left available for use. Whenever you look at your energy storage battery screen or BMS software, you'll see a battery percentage. Understanding SOC is essential for effectively managing and optimizing battery performance, ensuring. What is SOC (State of Charge) in Energy Storage Systems? State of Charge (SOC) is a critical metric in energy storage systems that indicates the current charge level of a battery relative to its full capacity.