Hi
Depending on the nature of the issue, your iPhone may require battery service.
Before contacting Apple, try the following steps:
Restart your iPhone (normally):
Check which apps are responsible for battery usage:
- Go to: Settings > Battery > under Battery Usage, select the Last 24 Hours tab.
- Address any issues with potentially problematic apps (such as by removing and reinstalling them).
Follow Apple's tips for maximising battery life, as detailed here:
- https://www.apple.com/batteries/maximizing-performance/
- About the battery usage on your iPhone, iPad, and iPod touch - Apple Support
When charging your iPhone, follow the instructions in the following support article, including:
- Checking the charging port for any debris.
- Using only a genuine Apple cable or an Apple-certified (MFi) cable.
- Apple recommends using the supplied USB Power Adapter.
- If your iPhone, iPad, or iPod touch won't charge - Apple Support
Check whether the issue persists after restoring your iPhone to factory settings:
- Back up your iPhone (you may wish to encrypt the backup, if using iTunes):
- Restore it to factory settings, with a fresh copy of iOS:
- Check whether the issue recurs before or after restoring from backup:
If the issue persists, I suggest that you contact Apple Support (remote diagnostics and mail-in service may be available), make a Genius Bar reservation or visit an Apple Authorised Service Provider for assistance, including - if recommended - to arrange for your iPhone to be checked and serviced:
- US: iPhone Service Answer Center - Apple Support
- Elsewhere: Apple - Support