The 10.5-inch iPad Pro comes with its own 12W USB power adapter but it should also be able to charge with the Apple 29W USB-C Power Adapter using USB Power Delivery. We look at the USB Power Delivery negotiations to see how well the newest iPad Pro performs with the Apple 29W charger.
The Apple 29W USB-C Power Adapter starts to communicate with the 10.5-inch iPad Pro after a hard reset by advertising its source capabilities of 12 watts (5 volts @ 2.4 amps) and 29.6 watts (14.8 volts @ 2 amps).
The 10.5-inch iPad Pro can be seen to request 12 watts (5 volts @ 2.4 amps) from the charger which it then accepts.
While being charged at a 5% battery level, the 10.5-inch iPad Pro is seen to draw about 30 watts (15 volts @ 2 amps) from the charger.
However with the 10.5-inch iPad Pro's battery at 81% full, it is observed to start pulling 12.5 watts (5 volts @ 2.5 amps) but then suddenly stops charging within the first 10 seconds. Charging then quickly resumes to happen at 18 watts (15 volts @ 1.2 amps).