Left click on the apple logo
We will want to leave the menu open, and look on our keyboard and locate the options or alt key, they are the same button. The about this mac option will change to system information.
Left click on System Information.
In the menu on the side you will navigate to Hardware and in that folder we will find Power.
When you open power, there will be a bunch of information on the right hand side of the window, locate the second section from the top, and you will see charge information just like the picture below.
YOU ARE DONE.