devices and methods for powering a medical device for sustained delivery of fluids or continuous monitoring of body analyte are disclosed . the devices may comprise a pumping mechanism , a driving mechanism for activating the pumping mechanism to dispense fluid , and a power source coupled to the driving mechanism and having an energy storage cell for providing a pulsed power to the driving mechanism . the methods may be implemented by activating the driving mechanism using pulsed energy in the form of at least one pulse train pattern accumulated in and discharged from an energy storage component .