An improved method and device for rapidly charging a battery by providing a charge pulse to the battery, followed immediately by a depolarization pulse created by allowing the battery to discharge across a load, followed by a stabilization period, and repeating this sequence cyclically until the battery is charged is disclosed. Preferably, the current level of the charge pulse is equal to or greater than the nominal rated current at which the battery can discharge in an hour, in order to achieve rapid charging. The duration of the charge pulse will generally be about one-tenth to two seconds. The current level of the depolarization pulse may be approximately the same magnitude or greater than the charging current, but of significantly shorter duration, such as 0.2-5% of the duration, to avoid unnecessary discharging of the battery. The duration of the stabilization period is generally greater than the magnitude of the depolarizing pulse. By optimizing these time and current characteristics of the charge, depolarization and stabilization periods for any particular type of battery, the battery may be charged most rapidly while prolonging the life of the battery. These characteristics may also be varied as the battery is charged based on the charge of the battery measured under load.