Some iPhone users may have noticed that their battey is not lasting like it used to .
This can affect all iPhone models so hear are 2 suggestions that may assist.
Try shutting down your phone and restarting twice.
If restarting your iPhone doesn’t work, try resetting your network settings:
This will erase your saved WiFi access points and passwords, reset your cellular network connection with the towers ( providers, and your connection to your provider basically starts afresh. After doing this you will have to reconnect to your WiFi points.
To try this fix, all you have to do is go to Settings > General > Reset > Reset Network Settings.