A battery always used to provide DC electric supply. These cannot be operated on AC supplies and these can be charged and reused and these cannot be charged and can be used only one time. Batteries consists of two terminals one is cathode and the other is anode. The cathode terminal is called the positive terminal of the battery and the anode terminal is called the negative terminal of the battery.in batteries current flows through the positive terminal to the negative terminal. Batteries consists of electrolytes which are the plates of the varied materials like sodium, potassium, chloride, calcium, magnesium and phosphate. These materials have the capacity to conduct electricity. When batteries are connected to the circuits the electrolytes start moving there ions and a chemical reaction is completed on both terminals and starts delivering energy to the connected circuit. This all process take place in a second of time and starts delivering power to the connected circuit.