iPhone by default displays the battery percentage in the status bar before the battery indicator bar. This is very useful to quickly find out the amount battery life left on your iPhone than from battery indicator bar. But for some reason if you do not want to display the battery percentage then you can turn off using the option available as part of the General Settings.
Step 1: Press the menu button to access the iPhone Home screen.
Step 2: Tap the Settings icon on the Home screen.
Step 3: Tap the General Option in the Settings screen.
Step 4: Then in the General Settings screen, tap the Usage option and navigate to Battery Usage section.
Step 5: Now you can turn off the display of battery percentage by setting the value of Battery Percentage switch to Off.