Your Apple Pencil doesn't have any sort of light that indicates its battery level. If you want to check how much battery power it has left, you'll need to use a widget on your iPad Pro.

According to Apple, the Pencil gets about 12 hours of battery life. If its battery ever runs out, you can connect it to your iPad Pro's Lightning port and get 30 minutes of use time from just fifteen seconds of charging time.

To view the widgets on your iPad Pro, open the Today view. You can do this either by swiping down from the top of the screen to view your notifications and then swiping right, swiping right from your leftmost home screen, or swiping right from the lock screen.

If you don't see a Batteries widget in the list here, scroll down and tap the "Edit" button at the bottom of the screen.

Locate the "Batteries" widget in the "More Widgets" list here and tap the "+" button to add it to the list.

Drag the slider to the right of the Batteries widget to arrange it where you like it reside. For example, you may want to place the Batteries widget at the top of the screen for easy viewing.

Tap "Done" when you're done.

You'll now see a Batteries widget that displays the battery level of your iPad Pro, Apple Pencil, and any other connected accessories---like Apple's AirPods. Just swipe back to the Today view whenever you want to check the battery level.

Image Credit: Denys Prykhodo/Shutterstock.com