Intel, Qualcomm, and Why Your Nexus 5X & 6P Can’t QuickCharge with USB-C

  • Google has inferred something troubling about the new Nexus 5X and 6P – they don’t seem to support Qualcomm QuickCharge technology. Despite the fact that QuickCharge 2.0 and 3.0 are compatible with the new USB-C port, the new Nexus Snapdragon 808 & 810 devices will only charge at standard USB speeds.

    In this article, we dive deep on Qualcomm, and Intel/USB-IF’s rival accelerated charging standards… and why Google likely cut a corner here.

    What is Qualcomm QuickCharge Technology?

    In a nutshell, QuickCharge is a tool that Qualcomm uses to push more power over USB lines, than the USB specification allows.

    The tactic is not new. Apple pioneered it, and got away without reprisal from the USB Implementation Forum. Apple has used the USB-IF to punish others (ahem, Palm), but this time – they got through without reprimand. Thankfully, it’s a good thing. It has helped prevent USB from needing auxiliary charging ports.

    When you plug an iPad into its USB wall charger, or an iPhone into a Macintosh computer – something special happens. The charger and mobile device perform a hardware handshake, by phasing their voltage regulation in a rhythmic manner. This variance is statistically impossible to occur otherwise, and validates that the two devices can supply and receive amperage higher than what the USB specification allows.

    HP followed suit with its webOS TouchPad, then Samsung did the same… and now Qualcomm has standardized the practice across multiple device makers, with one single standard. Since most high-end mobile devices today use Qualcomm SoC’s, it was logical for Qualcomm to provide the standard.

    By default, QuickCharge 2.0 provides up to 18W of power, through two alternate amperage/voltage combinations. The preferable rate is 9V, 2A – but it can also charge similarly using 12V and 1.5A.

    Google did, at least at one point, embrace QuickCharge 2.0. The Motorola Nexus 6 was one of the first devices to support QuickCharge 2.0.

    But now there’s USB-C. And that makes things more… interesting.

    USB-C And The Growing Charging Web

    Intel created USB, and it wasn’t going to sit idle as PCs, phones, and tablets converged. It has its own return-fire against QuickCharge.

    The world’s largest chipmaker comes from the PC universe, where laptops and 2-in-1’s routinely require dozens of watts of power. So, USB-C had to provide something more than just 15W to do everything Intel wanted from it.

    USB-C by default, adopts USB 3.1’s enhanced power delivery specification. A standard USB-C cable can handle up to 5 volts, 3 amps of power, for 15W of total power delivery. This is the same as what USB 2.0 and 3.0 devices could deliver – provided the manufacturer overcharged the cable. An ASUS Transformer Book T100 for example, comes with a 5V, 3A charger… but the charger notes clearly not to use it with other devices, because it is not USB certified (it supplies too much power, as 2.1A is the USB 2.0 cap).

    Alongside USB-C, there’s the all-new (optional) USB Power Delivery standard. Think of it as QuickCharge on steroids. It’s a new feature of the USB-C specification, that supports up to 100W of charging power, in a USB-C cable. The USB PD function, as it’s called, requires using the active switching cable options of the USB-C port that extends functionality to new technologies; Thunderbolt and DisplayPort Alternate Mode.

    Neither of the new Nexus devices benefit from USB PD (they don’t need it), but they do embrace USB-C’s native 15W charging. The first USB PD-enabled USB-C device, is Apple’s 12-inch Retina MacBook. The laptop benefits from being able to charge, and supply power to other devices, at up to 100W from a single USB-C cable.

    USB PD also supports daisy chaining. For example, you can have a MacBook plugged into the wall via a USB PD wall charger. And, that MacBook can then be plugged into a USB-C hub, that also gets power from the MacBook… and passes that power onto a Nexus 5X. The Nexus 5X, MacBook, and the USB-C hub, all pull down maximum power – up to 100W – from the a single USB-C AC adapter.

    Frustration Remains

    Now that you are briefed on USB-C and QuickCharge… hence the question – why don’t the Nexus 5X and 6P support QuickCharge? The Snapdragon 808 and 810 both are flagships for QuickCharge 2.0.

    Qualcomm has been adamant that Google didn’t need to take this step. QuickCharge 2.0 and 3.0 both support functioning over USB-C, just as it performs over older versions. You can use a USB-A to USB-C cable, plugged into a QC adapter. This is particularly nice during the USB-C transition, because, you were supposed to be able to keep your QC 2.0 charging gear – even while picking up (or rather, upgrading to) USB-C phones and tablets.

    To give another example that might further clarify, take the OnePlus 2. The OnePlus 2 uses a USB-C port and a Snapdragon 810. It supports QuickCharge 2.0 while using older chargers, when connecting a USB-A to USB-C cable. Also, it charges at 15W using standard-fare USB-C chargers too. This is how Qualcomm envisioned the transition – letting people charge at full speed using either their older QuickCharge 2.0 chargers (with a new cable) or with new USB-C pure chargers.

    So, we frustratingly, can’t get a clear answer from Google as to why LG or Huawei couldn’t, or weren’t allowed to use QuickCharge standard formally in the Nexus 5X or 6P.

    The most likely scenario is that Google instructed LG and Huawei to remove the authentication chip needed for QuickCharge 2.0. Unlike QuickCharge 3.0 and USB PD, QC 2.0 requires a physical chip in the device’s charging circuit – to enable the necessary hardware handshake.

    It is nice to remind people that neither Intel nor Qualcomm created this situation, and they are happy to support both their optimized charging standards (QC for Qualcomm and PD for Intel), and both at least USB-C’s baseline 15W charging.

    This could boil down to marketing dollars. Google may have declined to engage in the QuickCharge requirements to post advertising stickers, and also possibly pay extra certification costs to Qualcomm, to license the QuickCharge standard. Intel and the USB-IF, do not charge any fee to use USB-C Power Delivery, though cable and manufacturing costs may increase if you need 16-100W of power.

    But even that isn’t enough of an explanation. Qualcomm says the standard is open and royalty-free, provided certification is met. The QuickCharge support cost should be negligible… a few cents for a charging circuit.

    Unfortunately, unless Google is willing to speak more on the subject – or even better, try to work around this in baseband firmware – we may never know why Google chose to opt-out of QuickCharge 2.0. It doesn’t make sense to us.

    While it is possible that Google is still supporting QuickCharge 2.0, albeit, unofficially – we won’t be able to confirm until the devices ship. It just isn’t very likely.

    Who This Hurts

    Ironically, those that bought Nexus 6’s last time around, are likely to be the ones worst impacted by Google’s move to not include the QuickCharge 2.0 support.

    Arguably, Google may have felt that extra effort to support QuickCharge 2.0 on a marketing basis, was not needed, since USB-C provides 15W of power natively. Though this does dramatically impact consumers (like myself) who already own a series of QuickCharge 2.0 gear that predates USB-C. I already own a QuickCharge 2.0 portable charger (10,000 mAh), as well as two AC adapters, and two car adapters. Now, with Google’s move, all of those will likely throttle down to USB 2.0 (5V, 2A) speeds.

    Qualcomm’s original vision was that I would simply have to buy a couple of USB-A to USB-C cables, and all my QuickCharge 2.0 gear would keep charging at 15W… even that expensive 10,000 mAh portable charger. It was a standard built to be future proof. But, that required Google to opt-in on its new devices… which it didn’t.

    By blocking, or at least, not implementing QuickCharge 2.0 on the new Nexus devices, Google is forcing consumers like me to purchase all new, USB-C aware chargers. The thing is, there’s no benefit had QuickCharge 2.0 been implemented, both standards charge at 15W. This means people like me just blew upwards of $ 100 on QC 2.0 chargers, and now have to blow $ 200 on cutting-edge USB-C aware 15W portable chargers and AC/DC adapters. It’s a waste. A gigantic waste of money, time, effort, and e-waste.

    One Last Time

    Thankfully, while this is yet another costly technology/hardware migration, it likely will be the last one. The USB-IF has caught up with the demands of modern technology, and USB-C, USB Power Delivery, and QuickCharge 3.0, all appear to act together in harmony. With consumers focused on devices that last for very long periods, rather than consuming high-wattages of power, it’s unlikely we’ll need to buy new chargers again… for a much longer time to come.

    Full Disclosure: I run an Android-enabled startup that enhances Intel technologies. I’m also a distinguished developer with Intel. Intel didn’t ask me to write this article.

    Copyright 2015

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