Both battery and capacitor serve the same purpose, i.e, storing electric energy. But their functionality differs. This article discusses the similarities and differences between battery and capacitor.
- Difference between battery and capacitor (Short answer)
- Battery vs Capacitor: You should Know this!
- What is a battery?
- What is a Capacitor?
- Battery VS Capacitor- Efficiency
- 12 Difference between Battery and Capacitor- Table
- Similarities in Batteries and Capacitors
- The Supercapacitor – Battery+Capacitor
Difference between battery and capacitor (Short answer)
A battery stores energy in the form of chemical energy, while a capacitor stores energy in the form of electric field. As a result, batteries are better suited for applications that require a continuous flow of power, such as powering car accessories, while capacitors are better suited for applications that require short bursts of power, such as operating a camera flash.
- A battery has a better energy density than a capacitor, which means it can store more energy per unit volume.
- A capacitor is generally used for filtering applications, while batteries are used as power supply.
- A battery is an active device as it can supply energy for a continuous period. While a capacitor is a passive device as it cannot supply energy for continuous periods.
- Not all capacitors have polarity, ceramic capacitor for example, but all batteries have polarity.
- The dielectric material used in a capacitor can be optimized for specific applications. This ensures that the capacitor can function at its maximum efficiency for the given application.
There are some more differences that we will discuss, but first, let us understand some concepts related to batteries and a capacitor.
What is a battery?
Batteries store and release electric power. The energy in batteries is stored as chemical energy. Different types of batteries are available in the market. They differ in chemical composition, shape, size, nominal voltage, capacity, and many more features. Thus we can make a better choice of batteries for our purpose from this wide variety.
How does a battery work?
The three primary components called anode, cathode, and electrolyte are common in all batteries. The anode is the negative terminal and the cathode is the positive terminal. When the battery is connected in a closed circuit, the energy causes the flow of electrons from the anode to the cathode via the electrolyte. This flow of electrons results in electricity. Read more
Rechargeble and Non-rechargable batteries
When a battery discharges, it provides power to the circuit at a constant voltage (terminal voltage). Once the battery is drained out completely, it provides no more power. The rechargeable batteries can be reused because they can reverse the chemical reaction and restore energy. The non-rechargeable batteries are for one-time use.
What is a Capacitor?
A capacitor is a component that stores electric energy in an electric field. The major parts of the capacitor are two conducting plates separated by a dielectric. When the current enters the capacitor, the charge is accumulated on the plates. This generates a potential difference across the insulator.
Once it is connected to an electric circuit, the current discharges rapidly. Similar to that of a battery, every capacitor is designed for a specific capacitance that decides its capacity or storage.
Learn more about capacitors: A Beginner’s Guide to Capacitor (Symbol, Formula, Working)
12 Difference between Battery and Capacitor- Table
Now let us discuss some more difference between battery and capacitor.
|Energy storage||Energy is stored in the electric field.||Energy is stored in the form of chemical energy.|
|Passive/Active||It is a passive component.||It is an active component.|
|AC/DC||Ideal for AC applications.||Provides DC.|
|What’s inside?||Composed of thin metal plates separated by an insulator (dielectric).||Composed of metals and chemicals|
|Energy density||Lower energy density.||Better energy density.|
|Charge-discharge rate||Rapid charging and discharging rates.||Slow charging and discharging rates.|
|Run time||Instantaneous discharge.||Longer run time.|
|Temperature||Excellent temperature performance||More sensitive to temperature|
|Nominal voltage||Voltage decreases rapidly while discharging.||Provides a constant voltage till the cut-off.|
|Price||Higher cost.||Comparatively cheaper.|
|Applications||Perfect for high voltage and high-frequency applications.||Only a few models are suitable for high voltage applications.|
|Circuit polarity||The polarity of the circuit need not change while charging and discharging.||The polarity of the electronic circuit must be opposite while charging and discharging a battery.|
Similarities in Batteries and Capacitors
Although the batteries and capacitors differ in many aspects, their similarities are also significant.
- The major similarity lies in their application i.e., to store electrical energy.
- Both are capable to produce a potential difference across any component connected to it.
- Both the components have a series of resistance.
The Supercapacitor – Battery+Capacitor
While speaking about the differences and similarities between capacitors and batteries, the main objective is to land on a decision to make a choice between them. Both the devices have pros and cons. But what if there is a device that has the features of both capacitor and battery? That is why engineers came up with the component called supercapacitor. A supercapacitor has a very large surface area and is capable to store more energy than regular capacitors.
Features of supercapacitor
A supercapacitor is a hybrid as it shares the features of both capacitor and a battery:
- It has two conducting plates (like capacitors).
- These plates are called electrodes (like batteries).
- It stores energy on the conducting plates (like capacitors).
- The gap between plates is filled with an electrolyte, not with a non-conducting gap (like batteries).