Adam Conway, on XDA Developers:
The Xiaomi Mi Power Bank 3 has two USB-A ports and one USB-C port. The two USB-A ports can output at 5V/2.4A, 9V/2A, 12V/1.5A if only one port is used, or 5V/3A when both are. The singular USB-C port can out output at up to 45W. The Xiaomi Mi Power Bank 3 can charge in just 4.5 hours if you have a 45W charger. Using a regular 5V/2A charger will take about 11 hours to charge, while an 18W charger will take 6.5 hours.
Speaking of power banks, this will be my next purchase. 30 USD for 20K mAh capable of charging my MacBook Pro, iPad Pro, iPhone, and Apple Watch? ‘Are you getting it? These are not four separate devices.’