Development of Portable Fan

In the hot summer, people feel uncomfortably hot wherever they go. Therefore, I often carry a pu fan or a paper fan, so that I can use it to cool down anytime and anywhere. This is the simplest kind of Portable Fan, but this kind of fan requires manpower to shake the fan, and human activities cause more heat, so the actual use effect is not good.
With the continuous development of science and technology, people have invented electric fans, which are driven by electric motors to force air to flow. Instead of relying on manpower to shake the fans, people can easily and conveniently enjoy the coolness of artificial wind in summer. Since the ordinary electric fan completely relies on the electric energy of the mains power grid to provide energy to drive the fan, this has caused the limitation that it can only be used in cities where the mains power grid is drawn. Obviously, ordinary electric fans cannot be called Portable Fans.
In order to allow the electric fan, a comfortable cooling tool, to serve mankind anytime and anywhere, many electrical appliance manufacturers add batteries to the traditional fans. The place of use is not restricted by the mains grid lines, but is provided by their own batteries. Electricity, this advancement has made the portability of electric fans a big step forward.