Introduction 

One really interesting and useful gadget to have is a power bank. Almost everyone across the whole universe purchased or used a power bank. A power bank is basically a portable battery that can charge also any device a very helpful to carry in case of an emergency. In 2001 power banks first appeared in Las Vegas International Consumer Electronics show in 2001. The power bank concept was designed by a student with a few AA batteries and a circuit board. In 2013 the official portable charger was made by  David Wilkins, Jose Acosta, and Julian Sanchez. Throughout the years they have modified and made power banks better and well functional. There are different kinds of power banks for example if you have 5000 mAH or less it has one port and will charge your device slower compared to a 10,000 mAh or more will have more than one port and will charge faster. These portable chargers also come in different sizes and colors. 

Parts and components

Figure 1

In order to make a power bank first, we need to buy “LM7805 VOLTAGE REGULATOR”. The LM7805 contains 3 pins; input, ground, and output. The input function is to get 9v from the battery and regulate it to the output pin. Second, the function of the ground pin is to make ground for the regulator, lastly, the output pin is there to receive regulated voltage from the battery and the input pin

.Figure 2

A 9 voltage battery is the main source of voltage for this project to work.

Figure 3

 

Color	Description
Red	USB Vcc (+5v)
White	Data+ D
Green	Data- D
Black	Ground

 

Figure 4

The picture above is telling us to connect the battery with LM7805, the resistor and with the OTG cable. This is how to make a functional power bank.

Conclusion

By now almost all the companies have made power banks some are high quality and some are low quality. Getting a low-quality power bank can damage the battery of your phone. Some of the new power banks have 4 lights, which represent the battery level of the bank.1 light=0-25%,2 lights=25-50%,3 lights=50-75% and 4 lights=75-100%. Some power banks also have a built-in flashlight just to make their product stand out more. In the year 2020 having a power bank is a very essential gadget to have which means you can charge your phone on the go.