What's in the charger?

The principle of mobile power supply is simple. When an external power supply can be found, the built-in battery is precharged, that is, electric energy is input and stored in the form of chemical energy. When necessary, the battery will provide energy and generate electricity, the voltage converter (DC-DC converter) will reach the required voltage, and the output terminal (usually USB interface) will supply power to the required equipment for charging or other purposes.

fundamental/essential component

Mobile power supply has three basic functions, including energy storage, charging and power supply. Other functions such as safety protection, battery state detection and display are added to meet the needs of different designs, use and convenient operation.

Extended data:

Mobile power supply, mobile charger (mobile electricity, mobile charging, charging treasure, urine bag, wet nurse; English: Power bank is a portable charger that individuals can carry with them, and can store electric energy by themselves. Mainly for hand-held mobile devices (such as wireless phones, laptops) and other consumer electronic products, especially in the absence of external power supply. Its main components include: battery for electric energy storage, circuit for stabilizing output voltage (DC-DC converter), and most mobile power supplies are equipped with chargers as built-in batteries for charging.

The appearance of mobile power supply was originally used to charge consumer electronic products when there was no external power supply. However, because its output interface is a universal USB interface, it is also used as the power supply for other devices or devices with USB interface as the power input, such as USBLED lights and USB electric fans.