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Google 'Strongly' Recommends Against Third-Party Fast Charging Technology On Android (techcrunch.com)
An anonymous reader quotes a report from TechCrunch: Everyone, it seems, is going the fast charging route these days. Thanks to the nearing ubiquity of USB-C on flagship devices, the feature is quickly becoming a standard -- "standard" in the sense that everyone is doing it, not so much that there's any consistency to the tech. All in all, it's a nice addition to manufacturers' newfound focus on battery life. And while Google has embraced its own version on its new Pixel devices, the company's not so keen on letting everyone implement their own version. In newly released Android Compatibility Definition papers issued for Nougat, the company stops short of an outright ban on technologies like Qualcomm's Quick Charge, though it does take a pretty clear stand, "strongly recommend[ing]" against it. At issue, among other things here, is potential compatibility issues with standard USB chargers. Google said in its latest revision of the Android Compatibility Definition Document, "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."
The USB power delivery spec standardizes how to increase Vbus voltage and max current. Power profile 5 increases the voltage to 20V with 5A current for 100W of power. It can be implemented on either type A, micro USB, or type C. It used to be that the USB spec only standardized up to 7.5W power draw, which became a limiter on charging time. Now that we have the new power delivery spec extension, there are zero good reasons to implement proprietary charging standards to move beyond 7.5W.
Despite this, Qualcomm is still heavily marketing its proprietary quickcharge 3.0 system to smartphone manufacturers, purely for the incremental profits on licensed wall chargers. I'm glad to see Google throwing their weight around a little in an effort to shut down what is purely a money grab.
If only phones could be made thicker to increase battery capacity, no more carrying around fast chargers and power banks
There is a standard for faster charging. It's called USB-C, or if that isn't fast enough, USB Power Delivery. There are legitimate compatibility concerns over the various proprietary extensions that do the same things but differently.
I wonder how many of the Galaxy Note 7 fires were using rapid charging. Basically all google is really saying is follow the USB-C standard
Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.
I'm not sure what the article means by "its own version", but the official Pixel charger uses USB Power Delivery for 18W charging.
There's no inherent connection, except whatever software support the hardware might need. The guidelines/requirements here are for Google to allow hardware vendors to use the Android trademarks, qualify for Google Play apps, and so forth. Google is using that as an incentive for the third party vendors to use standard power mechanisms rather than proprietary ones.
I wonder how many of the Galaxy Note 7 fires were using rapid charging.
Interesting question though it wouldn't top my list of possible explanations I don't think it could be ruled out either.
Basically all google is really saying is follow the USB-C standard
It is incredibly naive of Google to trust that third parties will follow the USB-C standard if there is money to be made in not following it. There is an old saying that "people generally don't do what you expect, they do what you inspect". Or as another put it "trust but verify". If it is important enough to worry about then Google should be implementing measures to ensure that it will not work unless they follow the USB-C standard. If the USB-C standard provides no means to check if it is being followed then it is a flawed standard and should (in principle) be scrapped for a better one.
Because they know that people don't always use the chargers that came with their devices. People buy extras so they can have one at home and one at work. They borrow chargers from friends. Sometimes, they even plug their phones into their computers to charge.
If you plug a devices that was designed around the USB Power Delivery spec into a charger that was designed around a proprietary rapid charging standard, (or vice versa) the two devices aren't going to understand each-other correctly during the process of negotiating charge voltage, current limiting, and which data lines (if any) to use to supplement charge current.
It would REALLY suck your USB standard phone signaled the charger that it wants 5V@3A and the charger, which uses a proprietary charge protocol, misunderstood the message and not only upped VBUS to 20V, but put 20V across all of the data pairs as well.
If that were to happen and the phone were to be irreparably damaged, the blame is going to get spread around between the charger and phone manufacturers. And some people are going to look at the situation and switch to iPhones because "at least they don't have this problem."
Except my phone often can't keep up with my usage. I work 9 to 6 and get home with 50% battery or less, even if I don't use it much. Then maybe I need to go out, do some extra work, or even dinner outside. I don't use my phone while I have dinner, but I wouldn't want to have 30% battery or less if I have an accident or something. Or like when I got the call at 2AM that my uncle had died and had to stay up all night with my mom and aunt while the family made funeral arrangements.
Or maybe I live in the third world where a storm often knocks power out and my UPS only lasts for 30 minutes.
So yeah, I LOVE the Turbo Charge on my Moto X that can recharge to 100% in less than 1 hour.
Google is so large that "ex-Google engineers" just means "people". As in "Anker is supposed to be a bunch of people, right?" :-)
That said, I have a few of their products, which seem to be OK.
Bruce Perens.
Both are fine but they don't actually address what QC3 does, they just deliver more juice. QC3 will change voltage in 200mV increments on the fly, allow 2 chargers for lower temps and better heat distribution, and actively monitor the battery for conditions which degrade life. There is a lot more to it, but pushing more wattage through USB-PD is REALLY BAD FOR BATTERY LIFE. I wrote up some pretty in-depth articles on both USB-PD and QC3 lined below if you care.
This is the long way of saying what Google is asking for is idiotic. If you look at the size of modern batteries and the rate at which USB-C can deliver power, we are bordering on all-night charges already. If you up the delivered power via PD, you will not meet the 500 charge minimum life carriers demand thus not sell any phones. Worse yet that number is about to go to 800 really soon if it is not already there. Plus you will have people pissed off that their phone is drawing more current than the charger is supplying while plugged in and being used.
In short I question Google's sanity on this one. I am asking around to see what the official take on this is from involved parties, but I suspect the original article's take is way off base. I won't say why yet, I like to know before I mouth off publicly.
-Charlie
http://semiaccurate.com/2012/0...
http://semiaccurate.com/2015/0...
The cable itself has a maximum current which is independent of the device, and it can be one of three values. They didn't want every USB C cable to have to be built to carry 100 Watts.
Bruce Perens.