How to Turn Off Background App Refresh in iOS 11

With Background App Refresh turned on, the apps are automatically refreshed in the background and are updated or modified as needed.
Although it is a good idea to leave Background App Refresh enabled in order to keep your iOS device function smoothly and remain updated, doing so consumes some additional battery and Internet bandwidth.
If you have an Internet plan that comes with capping, or you want your iDevice to have more battery life than it currently has, turning off Background App Refresh might help.
Here’s how you can turn off Background App Refresh in your iOS 11 device:
    Get to the Background App Refresh window
    Tap Settings > General > Background App Refresh. This takes you to the Background App Refresh window. From here you can manage the settings to get optimum performance from your device.



    Manage individual apps
    Tap the apps’ toggle buttons individually. This keeps those apps from refreshing in the background. All the other apps continue to refresh in the background normally.

    Turn off Background App Refresh

Tap the Background App Refresh option from the top, and tap Off from the next window. This turns off the Background App Refresh feature on your device altogether. You can also choose to refresh the apps in the background only when your device is connected a Wi-Fi network by selecting the Wi-Fi option.