On iPhone models with Face ID, you can check your battery percentage in Control Center. On iPhone models with a Home Button, you can add it to the status bar.
To learn more about this topic, visit the following article:
Show the battery percentage on your iPhone, iPad, or iPod touch: https://apple.co/3P6LkMr
Additional Resources:
Get Support for iPhone: http://apple.co/iPhone
To subscribe to this channel: https://www.youtube.com/c/AppleSupport
To download the Apple Support app: http://apple.co/2hFtzIv
Apple Support on Twitter: https://twitter.com/AppleSupport
Apple Support Community: https://apple.co/38qiXsp
For more videos, go to Youtube Apple Channel