Cell behavior is numerically investigated for fast charging of a lead-acid cell under constant current or pulsed current. A model used in the simulation has been developed to predict the cell performance by considering the solid-state reaction at the negative electrode. By incorporating a rest period and a depolarization pulse on high rate charge, it is possible to avoid deterioration of the cell performance due to an increase in internal resistance. Thus, fast charging of a lead-acid cell can be achieved without a loss of cycle-life, despite the fact that higher currents are forced into the cell.