Xiaomi devices are known for their large batteries, but they typically do not support Qualcomm’s Quick Charge technology despite having the hardware capabilities. The Xiaomi Mi A1 is no exception, but it seems that is now changing. With the Android Oreo beta test release, Indian technology site Telecomtalk has confirmed that the device has now received fast charging support in the latest update.
The device charges to 100% in about 92 minutes according to their testing, much quicker than the current 2 hours or so to charge the battery to full. It should be noted that the website tested this new fast charging capability using OnePlus’ Dash Charger and not the stock charger that ships with the Xiaomi Mi A1, however.
The reason the device likely did not ship with fast charging technology on board is because while the hardware is there, Xiaomi likely did not pay Qualcomm the license to use Quick Charge. Furthermore, since there are no kernel sources released for the device yet, kernel developers were unable to make that change themselves.
The company had promised that the final release will be out before end of this year, so the wait isn't long (assuming everything in beta testing goes fine).
Source: Android Police