A device for controlling the discharge of a battery supplying an intermittent load, such as a nerve stimulation device. The device includes a controller which operates a switched inductor to feed a capacitor with numerous small pulses from the battery, thereby building up the charge and voltage on the capacitor, and occasionally discharging the capacitor to a load. The capacitor discharge is at higher current than the small pulses from the battery, so the battery is drained at small instantaneous discharge rates compared the too high instantaneous discharge current from the capacitor.