Smart Battery Case: Can't find notification center in ios11
The charging status a widget in the the Today View.


  If you already attached your iPhone to your case, look for the charging status in Today View on your iPhone.
  
  


Charge your iPhone with your Smart Battery Case

If the widget doesn't appear, tap the Edit button shown at the bottom of the screenshot and add it to the widgets you see.

To access Today View,


  swipe right over the Home screen, Lock screen, or while you're looking at your notifications.


Use widgets on your iPhone, iPad, and iPod touch

In addition, the charging status is shown on the lock screen briefly when you connect/disconnect the case or power.


  As you attach your iPhone to your case, a charging status appears on the Lock screen. The status also appears when you connect the case to power or disconnect from power.


Charge your iPhone with your Smart Battery Case