Hi
Depending on the nature of the issue, your iPhone may require battery service.
Before contacting Apple, try the following steps:
If you have not yet done so, update your iPhone to the latest software version:
Close all apps on your iPhone and restart it (normally):
- Double-click the Home button, then swipe up on the app previews to close each app.
- Restart your iPhone, iPad, or iPod touch - Apple Support
Follow Apple's tips for maximising battery life, as detailed here:
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 (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 (whether under warranty or via chargeable repair service):
- Contact - Official Apple Support
- https://twitter.com/applesupport
- http://www.apple.com/retail/geniusbar/
- https://locate.apple.com
To check your warranty status: