The key distinction between a battery and a capacitor lies in how they store electrical energy. While a battery stores energy in chemical form, converting it back into electrical energy as needed, a capacitor stores energy in an electric field. In this article, we will learn about the difference between a capacitor and a battery. First of all, we will learn what a capacitor and what a battery is.
What is Capacitor?
A capacitor is that electronic device that stores electrical energy in an electric field. It consists of two conductive plates with a gap filled with an insulating material called a dielectric. When a voltage is applied across the plates, positive charge accumulates on one plate while an equal amount of negative charge accumulates on the other, creating an electric field between them. The capacitor holds all the energy. The capacity of the capacitor to hold electric charges is termed capacitance.
Capacitors store energy by holding the pairs of opposite charges. While the basic capacitor is like two metal plates with a gap, capacitors nowadays come in many shapes, sizes, and materials. Capacitance is defined by the given formula :
C = Q/V
Where,
- Q is electric charge (in coulombs)
- C is the capacitance measured in farad
- V represents the voltage across the plates, measured in volts.
What is a Battery?
A battery is a device composed of one or more electrical cells that transform chemical energy into electrical energy. Essentially, a battery operates as a galvanic cell, facilitating redox reactions between two electrodes. These electrodes serve as the origins of chemical energy within the battery. Batteries can be mainly divided into two major types.
- Primary Cell / Primary battery
- Secondary Cell / Secondary battery
Batteries can be classified based on their applications into several categories such as household batteries, industrial batteries etc.
Difference between Capacitor and Battery
The difference between capacitor and battery is tabulated below:
| Basis of Difference | Battery | Capacitor |
|---|---|---|
| Definition |
A battery is a device which stores the electric charge in the form of chemical energy and back in the electrical energy when needed. |
A capacitor is a two terminals electronic component which stores the electric charge in the electrostatic field and discharge it back to the circuit as electrical energy. |
| Construction |
An ordinary battery consists of three essential components: a positive terminal (cathode), a negative terminal (anode), and an electrolyte. |
A capacitor is a two terminal comprises of two metallic plates isolated by a dielectric material such as air, mica, paper, etc. |
| Principle of operation |
The operation of a battery is based on the chemical reaction, called redox reaction (oxidation-reduction reaction ). |
The operation of a capacitor is based on the principle of electrostatic, i.e. when a voltage is connected to a capacitor, it begins to store energy in it . |
| Element type |
A battery is an dynamic component as it supplies energy to the circuit. |
A capacitor is inactive circuit component since it cannot deliver energy for infinite time. In straightforward word, it cannot supply energy to the circuit on its own. |
| Function |
The essential work of a battery in an electrical or electronic circuit is to give energy to the circuit. Moreover, a battery can produce electric charge. |
The capacitor as it were stores the electric charge or electrons. |
| Behavior with AC & DC |
A battery stores and produces as it were coordinate current (DC). AC cannot be utilized to charge a battery and the battery cannot deliver AC |
A capacitor charges in DC circuit slowly until it reaches supply voltage while in AC Circuit, a capacitor continues to charge and discharge continuously. |
| Types |
There are different sorts of batteries accessible such as Antacid battery, Lithium particle battery, Silver oxide battery, Nickel cadmium battery, Nickel metal hydride battery, etc. |
There are numerous types of capacitors like ceramic capacitor, mica capacitor, paper capacitor, electrolytic capacitor, electrochemical capacitor, super capacitor, half breed super capacitor, tantalum coordinates capacitor, etc. |
| Voltage |
A battery gives a consistent voltage while discharging. |
The voltage over a capacitor reduces rapidly while discharging. |
| Energy density | Battery has better energy density as compared to capacitor. | For a capacitor, the energy density is lower than a battery. |
| Terminal polarity | For a battery, the two terminals are positive and negative marked with their symbols | In capacitor, there are two terminals positive and negative. Here, generally positive terminal is longer of the two. |
| Charging and discharging time | The charging and discharging time of a battery is exceptionally high, regularly, 20 to more than 60 minutes. | The time taken for a capacitor to charge and discharge is very short, usually ranging from 1 to 10 seconds. |
| Life span | A battery has moderately life span almost 5 to 10 years. | The life expectancy of a capacitor is approximately 10 to 15 years which is comparatively more than a battery. |
| Size (for same capacity) | A battery is smaller than a capacitor. | A capacitor has lager size as compared to a battery. |
| Cost | Battery is very costly than a capacitor. | The price of a capacitor is less. |
| Applications | Batteries are broadly utilized as power source in various electronic devices such as torch, radio, toys, military and submarine appliances, automotive vehicles, backup power supplies, etc. | Capacitor is utilized in electrical and electronic circuit to present capacitance, some uses capacitors are as filters, power factor correction, motor starters, coupling and decoupling of signals, oscillators, etc. |
Conclusion
Both battery and capacitor are energy-storing components utilized in electrical and gadgets building. Be that as it may, these two gadgets are distinctive in numerous viewpoints such as their development, reason, working guideline, taken a toll, and numerous more.
Also, Check
FAQs on Difference Between Capacitor And Battery
What is capacitance ?
The ability of the capacitor to store charges is known as capacitance.
Are capacitors safer than batteries?
In common, capacitors are more secure than batteries, as they do not contain corrosive or flammable chemicals that can leak or explode.
Can a capacitor hold more energy than a battery?
No, batteries generally have a higher energy density than capacitors, meaning they can store more energy per unit of volume or weight.
How does a battery work?
In a battery, chemical reaction happen between the positive and negative terminals (anode and cathode) and the electrolyte, creating an electric current.