Batteries and capacitors are power electronic devices used for energy storage applications. Both of these devices can store as well release electrical energy. Though they resemble in many aspects, they have some differences as well. This article speaks about those differences.
Capacitors and batteries are capable of storing electric charge. But they store the charge in a different manner. Batteries store the electric charge in a chemical form while capacitors store the energy in the electric field generated between their plates.
The energy storage capability of a battery is very high than that of a capacitor with the same volume. That is, batteries are capable of storing thousands of energy per weight than that of capacitors.
Both the capacitor and battery have internal resistances. A capacitor has a lower internal resistance than a battery. Therefore, the capacitor charges and discharges in a faster way than a battery does. Also, a capacitor can deliver a higher current than a battery with the same voltage handling capacity.
Batteries provide a constant output voltage. So they are used as a DC source in electrical circuits. But capacitor blocks DC voltage and acts as an open circuit when a dc voltage is applied across its plates.When an AC voltage is applied across the capacitor, an electrostatic field is generated between the plates of it and energy flow takes place. So they are used as AC components.
