The Samsung Galaxy S8 is the first Galaxy phone to support USB Type-C and we are excited to find out what fast charging technologies that are enabled through this connector.

First, we look at how the Samsung Galaxy S8 charges with its Samsung Adaptive Fast Charging Charger that came with the phone. The Samsung Adaptive Fast Charging Charger uses Samsung's proprietary quick charging scheme to rapidly charge Galaxy phones.

We can see that when the Samsung Galaxy S8 is locked, the phone charges at about 11.7 watts (9 volts @ 1.3 amps). When the phone is awake and operational, it pulls 5.5 watts (5 volts @ 1.1 amps) from the charger.

The Samsung Galaxy S8 reports that the phone will take 1 hour and 38 minutes from just 1% battery while being charged with the Samsung Adaptive Fast Charging Charger.

We then looked at charging the Samsung Galaxy S8 with a USB Power Delivery enabled Innergie PowerGear USB-C 45 charger.

This time we can see USB Power Delivery transactions. The Innergie PowerGear USB-C 45 first declares it can support the following power profiles: 15 watts (5 volts @ 3 amps), 36 watts (12 volts @ 3 amps), 45 watts (15 volts @ 3 amps), and 45 watts (20 volts @ 2.25 amps).

The Samsung Galaxy S8 then requests 15 watts (5 volts @ 3 amps) from the charger.

We can then confirm that the Samsung Galaxy S8 is pulling 11 watts (5 volts @ 2.2 amps) from the Innergie PowerGear USB-C 45 charger.

Given that the Samsung Galaxy S8 is using a similar amount of power from both the Samsung Adaptive Fast Charging Charger and Innergie PowerGear USB-C 45, it's not surprising that the Battery Usage screen reports a similar amount of time needed to charge the phone to full from 1% charge.

Finally, we see how the Samsung Galaxy S8 charges with a Qualcomm Quick Charge 3.0 charger like the Ventev Wallport rq2300 Wall Charger. Here we see similar behavior that we saw with the Samsung Adaptive Fast Charging Charger. When the phone is locked, the phone charges at about 13.5 watts (9 volts @ 1.5 amps) with a lot of current variation. When the phone is awake and operational, the phone pulls 6.3 watts (5 volts @ 1.25 amps) from the charger.

Although the wattage pulled by the Samsung Galaxy S8 from the Ventev Wallport rq2300 Wall Charger is a little higher than the other two chargers, all three have a similar charge time of a little less than 1 hour and 40 minutes when the battery is near fully depleted.

The Samsung Galaxy S8 seems to prefer charging under 15 watts no matter what type of charging technology is used with the phone. Unlike other phones which are very aggressive in supporting 18-27 watts of charging, the Samsung Galaxy S8 is playing it safe when it comes to fast charging which is probably good considering what happened to the Samsung Galaxy Note7.