How to Check AirPods Battery Life Using the Case
In the same way you initially paired your AirPods to your iPhone, lifting the lid of the AirPod case brings up a display on the phone that shows the battery life for each AirPod and the case.
How to See AirPod Battery Life From the Lock Screen
You can also check the AirPods battery life from the Lock screen widget. Using the widget shows both the AirPods and the case, depending on which of the items are within range. The widget also appears if the AirPods are charging. To check the battery life using the Lock screen widget, swipe down from the top of the iPhone screen to reveal the Notification Center and then swipe to see the Batteries widget. If your phone is unlocked and on the Home screen, swipe right to see all the enabled widgets.
Check AirPods Battery Life on Apple Watch
Not only can you check your AirPods from your iPhone, but you can also check the battery life from your Apple Watch.