 Batteries, both rechargeable and non-rechargeable, are the main source of power supply for sensor nodes.They are also classified according to electrochemical material used for the electrodes such as NiCd (nickel-cadmium), NiZn (nickel-zinc), NiMH (nickel-metal hydride), and lithium-ion.Current sensors are able to renew their energy from solar sources, Radio Frequency(RF), temperature differences, or vibration.