In order to select the right supercapacitor for an application four basic parameters are required, nominal operating voltage, minimum allowable voltage, average capacitor discharge current and the duration of the discharge. With these parameters the maximum allowable equivalent series resistance (ESR) and the minimum capacitance can be calculated and a basic capacitor selection can be made. Using the additional criteria of operating temperature range and life allows for changes in the capacitor parameters over time and ensures sufficient design margin when making the capacitor selection.