A medical device includes a pulse generator that selectively generates pulses. A control module selectively controls the pulses A power distribution system supplies power to said medical device. The power distribution system includes N batteries, where N is an integer greater than one, a common node, and N protection modules. The N protection modules communicate with the control module, selectively connect a respective one of the N batteries to the common node based on control signals from the control module, and monitor current provided by the respective one of the N batteries. The control module generates the respective control signals based upon the current.