You can check first to see if there is a problem with the non-charging head and data cable. It may also be that the phone does not recognize the fast charging function of the charger.
First turn off the battery of the phone until the automatic shutdown, and then plug in the original charger to charge, do not turn on and keep the shutdown charging, until the breath light turns green and 100% power before turning on. Slow charging without fast charging may be that your phone is charging by usb charging, the above method can be switched to AC charging (that is, fast charging).
Enter the phone's [Settings] - [About the phone] - [MIUI version], and then click 5 times in a row, you can open the [developer options], turn off USB debugging, revoke all USB debugging authorization, and then return to the status information in the Settings to see whether it is in AC power charging.
Huawei and Xiaomi use private fast charging agreements, that is, Huawei's charging head is unable to support the Xiaomi charger fast charging. If you want to quickly make the Xiaomi charging bank fully charged, you can consider the recently popular South Carolina C1 charging head. The C1 charging head is small in size, but it can simultaneously support fast charging of three different protocols: 5V=3A, 9V=2.22A, 12V=1.67A.
Regarding the above Xiaomi charging treasure, if you want to use Huawei charging head, if your Huawei charging head is 5V\/2.1A, it is OK, because the Xiaomi charging treasure is used for 5V\/2.1A charging treasure dedicated charger input charging.