A mobile power bank is not basically a capacitor. It is a portable device that stores electrical energy in rechargeable batteries and provides power to mobile devices via USB connections.
Engineers choose to use a battery or capacitor based on the circuit they're designing and what they want that item to do. They may even use a combination of batteries and capacitors. The devices are not totally interchangeable, however. Here's why. Batteries come in many different sizes. Some of the tiniest power small devices like hearing aids.
So not only is the total energy density of the capacitor much lower than that of the battery, we can't even use all the energy that's there. So we can't effectively use capacitors in our cell phones because the phone would either last a tenth as long (probably less), or it would be ten times as large (probably more).
However, for devices that need consistent, long-term energy supply, a battery is still the best option. You can easily charge a capacitor using a battery. The charging process is quick, and this is commonly done in circuits where capacitors are used to smooth out power supplies or manage energy flow.
Is a battery a capacitor?
Capacitor: A capacitor discharges very quickly, which is why it is often used in situations requiring a rapid release of energy, such as in audio battery capacitors for amplifiers or subwoofers. No, a battery is not a capacitor. While both batteries and capacitors store energy, they do so through fundamentally different mechanisms:
Today, designers may choose ceramics or plastics as their nonconductors. A battery can store thousands of times more energy than a capacitor having the same volume. Batteries also can supply that energy in a steady, dependable stream. But sometimes they can't provide energy as quickly as it is needed. Take, for example, the flashbulb in a camera.
Should you use a battery or a capacitor in the automotive industry?
Batteries are also capable of delivering a consistent power output over a longer period of time. Overall, the choice between using a battery or a capacitor in the automotive industry depends on the specific application and the desired performance characteristics.