Who knew charging a device could be so complicated?!
So I thought it might be a good idea to post a topic for the differences, advantages, drawbacks and compatibility between these two standards for charging USB C devices.
I am in no way an expect when it comes to electrics, but I’ve been looking into USB C charging since getting my new phone, and being bamboozled by numbers! Feel free to post your opinions on each method of charging, and correct me if I am wrong.
Qualcomm Quick Charge
QC 3.0 outputs max 18W at 3A. 3.6V-20V in 200mV increments.
Advantages: Already implemented in many phones and 3rd party accessories.
Disadvantages: Takes of the data lines in the USB cable to enable fast charge. Not USB-IF compliant
USB-C PD (Power Delivery)
Up to 100W - (20V, 5A)
In practice however, a USB C PD phone charger will be more like
18W (5V,3A) (9V,2A)
Advantages: Uses dedicated power lines within the USB C cable, so less chance of devices receiving the wrong charge.
Complies with USB-IF standards.
Disadvantages: Lack of 3rd party accessories so far. Possibly going to be variation with cables due to the vast range of power they can supply.
"Old phone charger"
Usually around 5W - (5V,1A)
Advantages: every device can be plugged in to it.
Disadvantages: Cannot output enough power to use and charge a modern smart phone.
From the looks of things, if you are using a USB A-C cable then QC and PD are pretty much the same.
However I am unsure if QC always forces power through the data lines, or if it only does this when the device receiving power request it. If it simply acts like a normal charger until it detects a QC enabled phone however, it should be fine to use with a PD device.
It is when using USB C - C cables the USB PD takes the lead, and is much more future proof in my opinion.
For those that have not found it yet, Googler Benson Leung has started a spreadsheet of accessories that have been tested