The possible reasons are as follows
1, the voltage is not enough: it is recommended to change the jack, such as originally plugged in the computer charging, change to the socket.
2, the charger or data cable is not original: replace the original phone data cable and the original charger and charge again.
3, check the room temperature is not too low: Apple for the iPhone battery set the temperature is too low protection, the temperature is too low sometimes the phone will not be able to charge, in order to prevent deposition in the battery, resulting in internal short circuit of the battery.
4, the charging head has been used for a long time or the interface is dirty: change a charging head. Take a fine piece of metallographic sandpaper and cut it to the right size, fold it in half a few times, and gently rub it in the joint.
5, the charger or data cable is broken: it is recommended to change the data cable or charger.
Contact is not good, look at the mobile phone charging port! If you can move it again! Can go to change the charging port, is the phone used for a long time?