Be Wary of False Advertising: Qualcomm Quick Charge is not USB Type-C Spec Compliant
Benson Leung is a Google engineer who has recently become well-known for his third-party USB Type-C cable reviews. He has dedicated some of his time to testing which cables are spec complaint and which are not (sometimes resulting in catastrophic consequences for his own personal hardware) and has become the go-to guy for many users looking to purchase new cable accessories. That’s why when he stated that “you’ll never see [him] recommend the LG G5 or the HTC 10 phones” on a recent Type-C to Type-C cable review, people’s heads started to turn. Why? Because neither phone is compliant with the USB Type-C specification.
A little background information on charging technology will help in understanding this. For the longest time, USB 2.0 was the industry standard for power/data transfer. Only recently has the industry begun to adopt USB 3.0, and it was mostly only found in the laptop/desktop class of devices. Rather than wait for the industry to adopt the latest USB specification, companies like Qualcomm and Oppo decided to implement their own proprietary charging standards in order to bring faster speeds well before the industry caught up. However, the time truly has come around for USB 3.0 to make its debut in mobile devices, and we’re seeing more and more devices adopt the industry standard. Google’s very own Nexus 5X and Nexus 6P, for instance, feature the new standard Type-C fast charging technology (you’ll notice that the connections between the phone and the charger brick are both USB Type-C for the new Nexus devices, which is not true for USB Type-C QC-compliant chargers). It’s worth mentioning that USB Type-C and USB 3.0 are not synonymous, as the “Type” refers to the connection type and the number refers to the power/data transfer speed that the cable supports. Hence, the issue with OnePlus 2’s USB Type-C 2.0 cable.
However, herein lies the problem. Many companies are adopting cables with the USB Type-C connection type for their chargers. Why? Because it solves that age-old problem of figuring out which way to plug in your USB cable, of course! In addition, the name “Qualcomm Quick Charge” has become somewhat of a household name among people who research their phones before buying. A quick Google search for “Nexus 6P” with “Qualcomm Quick Charge” gives you loads of results of people and articles wondering or explaining that the 6P and 5X don’t support Qualcomm’s Quick Charge, but it does support fast-charging still! Clearly, the confusion here could cause trouble with some consumers, so why not create a USB Type-C Qualcomm Quick Charge compliant cable? Well, they did, which is how you end up with devices like the LG G5, HTC 10, and Nextbit Robin.
Consider the time-period before the USB Type-C spec became standard. In order to draw more power out of already-existing USB Type-A 2.0 cables, Qualcomm had to do some clever modifications in order to allow for the charger to draw more power. The same goes with QC 3.0 compliant devices using USB Type-C. As Benson Leung points out, these devices modify the VBus on the cable to allow for variable voltage output. They also take over the USB data transfer lines and alter the roles from sources to sinks in order to draw even more power for charging, while sacrificing the ability to transfer data over USB. However, both of these modifications are expressly forbidden in the new USB Type-C specifications under section 4.8.2 as Mr. Leung points out. Thus, any device that utilizes a USB Type-C connector and purports to be compatible with Qualcomm Quick Charge is not USB Type-C spec compliant.
What does this mean for the end user? If you stick with the stock charger provided to you by the manufacturer, likely nothing. Though Mr. Leung does not recommend these devices for failure to be compliant, this does not mean these chargers are unsafe to use. However, I would be extra cautious of any third-party, cheap sellers of USB Type-C cables online who purport to be QC compliant. Such manufacturers of these cables may attempt to jump on the “I am USB Type-C compliant AND I support Qualcomm Quick Charge” bandwagon when this is in fact impossible. Who knows what could happen if one of these third-parties messed with the VBus in a potentially dangerous way that could fry one of your expensive devices.