Battery level on Apple Pencil

By plugging it into the iPad and swiping to the left - you should see both the iPad's and Pencil's battery status.

And if it is the second generation pencil, just swipe to the Today screen and you should see the battery level if you have the battery widget on. If not then attach it to the side/top of the iPad, depending on the orientation you are using, and it will flash up the charge level to show it is charging.

You are welcome!