one
The charging head used is not an official original, and when the charging head output current is insufficient, the phone cannot enter the fast charging mode
two
If the quality of the charging cable used does not meet the requirements, it is recommended to use a randomly adapted charging cable, and then try again
three
System reasons, there may be some bugs, resulting in the phone can not automatically enter the fast charging mode, at this time, it is best to reinstall the charging connector
four
If the charging head and cable are not problematic in use, it may be due to the failure of the fast charging mode caused by the hardware of the phone, it is recommended to sell the phone