What happens if you use the Apple 29W USB-C Power Adapter to charge the HP Chromebook 13 G1?
Using software from Granite River Labs, we can see that the Apple 29W USB-C Power Adapter first offers 12 watts (5 volts @ 2.4 amps) and 29.6 watts (14.8 volts @ 2 amps).
The HP Chromebook 13 G1 first requests 5 volts @ 2.4 amps from the Apple 29W USB-C Power Adapter.
After the Apple 29W USB-C Power Adapter provides this 12 watts of power to the HP Chromebook 13 G1, the HP Chromebook 13 G1 then requests 14.8 volts @ 2 amps (30 watts) allowing it to charge much faster.