SoC (State of Charge)

State of Charge is the percentage of usable energy left in the battery. SoC is reported on the dashboard like a fuel gauge. Most EV manufacturers recommend keeping daily charging between 20 and 80 percent for battery health. Lithium ion cells degrade faster when stored at 100 percent or run repeatedly to 0 percent. Above 80 percent SoC, charging speed drops sharply because the cells need to balance and dissipate heat. The 20-80 window also charges fastest on DC fast — typically 18 to 25 minutes versus 45+ minutes for 0 to 100. Calibrate the gauge once or twice a year by charging to 100 percent and letting it sit briefly, otherwise the displayed SoC drifts from actual capacity.