#1 What adapter should I use to recharge the U Battery?
The USB C port supports input and output with 5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/2.25A. The USB A port supports output with 5V/3A, 9V/2A, 12V/2.25A
#2 What type of the devices can I charge with the U Battery?
Litheli U Battery with 45W Max output can charge your Macbook Air and phones. The massive 20000mAh U Battery provides 5 charges for iPhone 12, more than 4 full charges for Samsung Galaxy S10, and over 2 and a half charges for iPad mini 5.