The Samsung Chromebook Pro uses USB Power Delivery 2.0 technology to rapidly charge with its own shipped 30 watts based power adapter through the USB Type-C connector which we observed below.
Upon plugin to the Samsung 30W USB Type-C PD AC Adapter, the Samsung Chromebook Pro while on a fully depleted battery initially pulled quick changing current between .5-3 amps to briefly draw at most 15 watts (5 volts @ 3 amps) from the charger. After the voltage increased from 5 volts to a 15 volts rail, the current eventually settled out resulting in around 30 watts (15 volts @ 2 amps) of constant charging. Click here to download the trace captured by the GRL-A1 power analyzer to see more details.
The Samsung Chromebook Pro performs well with its own 30W charger to be able to max out charging in just under 10 seconds from first plugin.