I am a hobbyist and I have an idea in mind that I would like to implement. The idea is based on how a mobile phone works it has a screen and a battery, and we charge the battery using a charger while monitoring the battery status on the screen.
I want to implement a similar concept using a microcontroller. I have a PIC18F45K22 microcontroller and a JHD LCD. However, I don’t have a battery or a proper setup to charge a battery, since most modern mobile batteries are inbuilt. Also, I have limited resources.
So, my question is: I have a 5V 2A adapter. can I use it in place of a battery? If I connect a potentiometer in between, can I safely use it to complete my project?

 

No idea what you want to do or implement on this project of yours. If all you need is a 5V voltage source then the adapter will work for that but you can't add a potentiometer to a power supply to make it have true battery charging/discharging energy properties.