The proliferation of USB Type-C is making charging various devices easier than ever. Smartphones (other than the iPhone) and laptops are unifying under a single charging port, allowing any charger to plug into anything else. Today you can plug your Type-C phone into your Type-C laptop charger, and charging will happen. But because phones and laptops probably support different quick charging standards, the charging speed will be slower than it could be.
The two competing quick charging methods out there are the proprietary Qualcomm Quick Charge and the USB Power Delivery from the USB-IF standards body. Qualcomm has a near-monopoly in the high-end smartphone SoC market, so nearly every high-end device supports Qualcomm Quick Charge. Qualcomm SoCs don’t really exist in the laptop market, so Type-C laptops from Apple, Google, and others use USB Power Delivery (USB-PD). Neither one is really better than the other, but the incompatibility means you’re only getting basic charging speeds when you swap chargers.
To try aiming for quick charging unity, Google is telling Android OEMs to ditch Qualcomm’s quick charge implementation and switch to USB-PD. Google seems really serious about this, as it has started to write quick charging language into the Android Compatibility Definition Document (CDD) that every OEM licensing Google’s Android apps must follow. The new clause in the Android 7.0 CDD reads:
Type-C devices are STRONGLY RECOMMENDED to not support proprietary charging methods that modify Vbus voltage beyond default levels, or alter sink/source roles as such may result in interoperability issues with the chargers or devices that support the standard USB Power Delivery methods. While this is called out as “STRONGLY RECOMMENDED”, in future Android versions we might REQUIRE all type-C devices to support full interoperability with standard type-C chargers.
“Proprietary charging methods that modify Vbus voltage” is Google specifically calling out Qualcomm Quick Charge as an unapproved charging method, and “Standard Type-C chargers” is a thumbs up for USB-PD.
Google’s use of language in the CDD is very specific. It’s a big list of requirements and recommendations, but only points with the word “MUST” are actual requirements. For now Google only says USB-PD is “RECOMMENDED,” which doesn’t really mean anything—Google is just asking OEMs nicely to adopt something, which rarely works in the Android ecosystem. The real announcement here is that in “future Android versions” Google “might REQUIRE” full Type-C charger compliance, which would outlaw Qualcomm Quick Charge. If the past has been any indication, it will take a hard requirement from Google to see any real change happen across devices.
We’ve seen the company take the same approach with default full-disk encryption on Android. It was only “very strongly RECOMMENDED” in Android 5.0 Lollipop, so no one did it other than Google. Default encryption became a “MUST” for high-end devices shipping with Android 6.0 Marshmallow, and then we saw other OEMs adopt it.
There will always be a limitation to how much voltage any given charger can put out, but there’s really no reason to have dueling quick charge standards. Qualcomm Quick Charge was a real commercial product feature before USB-PD had gotten off the ground, so it had its uses. Now that the USB-IF has weighed in, though, it’s probably best to go with the “industry standard.” The only two companies with the power to change it are Qualcomm and Google, and Qualcomm probably enjoys the lock in and extra licensing fees. Google has been a big promoter of the Type-C standard, and this change indicates the company will use its power in the Android ecosystem to force everyone to the same power delivery standard.