A battery is a power device which consists normally of one or more electrochemical cells. Batteries come in all shapes and sizes ranging from single use (sometimes referred to as Primary) or multi use (sometime referred to as Secondary or rechargeable). Batteries come in an array of voltages and currents, which dictate the number of cells and the size of the battery. The main function of a battery is to give power to a device or set of devices in applications where a mains power is unavailable or not required. Examples would be hand-held applications, portable, sensors, IoT and others applications requiring portability and/or standalone requirements.