GTrusted
By attaching the Google Universal 22.5 W Dual Port USB Type-C Charger to the USB Type-C port of your Samsung Galaxy S8, both of which support USB Power Delivery technology, we'll see how well the external charger can deliver power to the Samsung phone.
Unfortunately since the Google Universal 22.5 W Dual Port USB Type-C Charger doesn't use a USB Power Delivery controller, the charger can't establish an active USB Power Delivery protocol negotiation with the Samsung Galaxy S8.
Looking at the power graph, the Samsung Galaxy S8 draws just 9.5 watts (5 volts @ 1.9 amps) from the Google Universal 22.5 W Dual Port USB Type-C Charger while being charged from a fully depleted battery.
