Charge other things (like Switch) with MBP 15 USB-C charger

Discussion in 'MacBook Pro' started by aevan, Mar 15, 2017.

  1. aevan macrumors 68000

    aevan

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    #1
    Ok, so I just got my Nintendo Switch (a.k.a. the Zelda machine), and it can charge fine with my MBP 2016 15" power brick, since it's USB-C. It's the future! Hurrah! And it's very practical, since I carry my MBP and its charger with me anyway.

    However - I'm still reluctant to charge something as small as the Switch with an 87W power adapter. Ryan from Anandtech replied to my question via Twitter, saying that there's no harm in charging the Switch with the MacBook's Power Adapter, as it won't pull more power than it needs.

    Still - and I'm sorry if I asked something similar around here already (can't remember, really) - is this.... safe? Is it ok? I'm the kind of guy who won't even charge his iPhone with the iPad charger :) Everything I read so far says it's safe, but then again, maybe people just don't care that it shortens battery life or something.

    So, thoughts?
     
  2. Sanpete macrumors 68020

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    #2
    It's designed to be used with a 39 W charger, right? Doesn't seem safe to me, but I'm no electrician.
     
  3. thesaint024 macrumors 6502a

    thesaint024

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    #3
    Funny. I was wondering the same thing about my MBP 65w charger and my Gopro Session. I did it anyway because there was no warning not to. Charged up fine, but I was a little hesitant to keep it on there for more than a couple hours. I also welcome a definitive answer about this new usb-c frontier of universal charging.
     
  4. aevan thread starter macrumors 68000

    aevan

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    #4
    Supposedly, it draws just how much it needs, not more.
     
  5. jerryk, Mar 15, 2017
    Last edited: Mar 15, 2017

    jerryk macrumors 68020

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    #5
    That is how chargers work. If not the charger for a 15" MBP could not be used for a 13 MBP. And people do this all the time. Same with the older Magsafe chargers, and charging a phone with charger that came with a tablet, which people do all the time.

    In fact, many of the wall sockets in my house have a 5V, 2.5 Amp USB A chargers built in. We charge phone that came with 5V 0.5 watt chargers, and tablets that came with 5V 2.1 watt chargers all the time.

    USB-C just has an expanded power capability. See this page for more info https://en.wikipedia.org/wiki/USB#PD
     
  6. Sanpete macrumors 68020

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    #6
    Those are at the same voltage. The MBP charger can go over 20 volts, the Switch is designed for 15.
     
  7. jerryk macrumors 68020

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    #7
    Valid point, but the Apple charger should support PD according to the wikipedia page.

    But the issue may be the switch. People on reddit are having issues with chargers because the switch is not sending the proper power request. https://www.reddit.com/r/nintendo/comments/5x7445/psa_nintendo_switch_uses_usb_pd_power_delivery/ This references some Anker charger. But then say "At the moment, I cannot recommend any Type C battery to power a docked Switch, as there are no spec compliant chargers that I know of that can do 9V, let alone 15V."
     
  8. Sanpete macrumors 68020

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    #8
    Ah, I see. Well, if that works as described at the Wiki page, it should be fine, I suppose. The chart there shows the charger should offer 15V at 3A, which should work. But as you say, the Switch may also have to be compliant, and that we don't know about.
     
  9. aevan thread starter macrumors 68000

    aevan

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    #9
    I understand that some chargers are not capable of charging the Switch while playing, as they do not provide enough power. But there's no talk about them actually damaging the console.

    I already tried the MBP charger and it works fine. I was just worried that it could damage the battery. But it would seem that's not going to happen for the reasons you mentioned.
     
  10. jerryk macrumors 68020

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    #10
    Usually if the was a voltage incompatibility you would know pretty quick. Just check it as you charge and see if the charger or Switch is getting hot. Of the all the companies out there, the one I would trust most to fully, and correctly, implement USB-C Power Delivery would be Apple.

    BTW, how is the switch? All the old titles available?
     
  11. Obagleyfreer macrumors member

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    #11
    Volts get pushed to the device via charger. You MUST make sure the voltages are the same or you risk damage.

    Amps are different, the device draws the amps from the charger, so the device will only use what it needs.
     
  12. aevan thread starter macrumors 68000

    aevan

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    #12

    And still I'm getting contradictory information! Some people say - sure, it's fine, others (like you) say it could be dangerous.

    I know there was this big thing on the Internet how the best charger for the iPad Pro is the MacBook USB-C charger. Serious websites measured the increase in charging speed, lots of recommendations left and right, people have been using them on iPads without issues. And the MacBook USB-C charger is 14.5V while the iPad Pro charger is 5.1V

    I'm not saying that different voltage can't damage equipment - I have no idea. But - isn't there some type of smart charging involved, where the charger is "smart" enough, and the device is "smart" enough to use everything properly?
    --- Post Merged, Mar 16, 2017 ---
    Well, I like it a lot as a secondary console. I think a PS4 is much better value for the money and certainly the better choice, but if you already have it and want something on the go - the Switch is really, really cool ;) It feels good. Really good.

    As for the games - I haven't seen old titles, but I'm not even sure what those titles are, since I'm not a Nintendo gamer. Like most people, I bought this to play Zelda, and new Super Mario games (when they are out) and I'm hoping we'll see some new Metroid and other Nintendo games. Basically, this is my entrance into the Nintendo world.

    BTW, the games store is just sad :) It reminds me when I had my old Nokia N900 and browsed the few games they had for the Maemo OS :) However, I do believe we'll see a lot more soon, and I knew what I was getting this for (as I said - a secondary console for a few titles to take with me).
     
  13. Gav2k macrumors G3

    Gav2k

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    #13
    The charger complies with USB 3.1 standards so a negotiation takes place when it's plugged in and the correct wattage and amperage are delivered. It's as simple as that.
     
  14. aevan thread starter macrumors 68000

    aevan

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    #14
    Yes, I just heard the same from a friend - basically, the USB 3+ takes care of regulation, both voltage and amperage and wattage so it's safe to attach any proper charger to anything. Worst case scenario: it won't charge, or it will charge slowly. But it won't damage the device.

    In other words - you can charge the Switch with the MBP charger :D
     
  15. xWhiplash macrumors 65816

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    #15
    How is getting hot an indication that something is wrong? My iPhone gets hot when I charge with the Apple supplied charger, or even on the slow USB 2 charging.
     
  16. Obagleyfreer macrumors member

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    #16
    I guess with the new usb-c protocol things could be different, and you're right, they very well could be "smart" now.
    I'm old skool, so my knowledge could be obsolete with new technology.
     
  17. hallux macrumors 68020

    hallux

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    #17
    I believe it's actually USB-C's PD spec, not USB 3.1. But, yes, it's part of a new USB spec.

    Here's some reading about it from USB.org USB.org - USB Power Delivery
     
  18. LunchMercenary macrumors newbie

    LunchMercenary

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    #18
    I've been charging my Google Pixel with my MacBook charger and it's been fine so I'd imagine it's fine for a Switch as well.
     
  19. aevan thread starter macrumors 68000

    aevan

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    #19
    Nope, after some digging and a few confirmations, I can say it's definitely and USB 3+ spec, USB-C is just the port type. So, any USB 3 port will regulate charging. USB-C, however, brings some benefits like reliability and universality (and in a few years, ubiquity).
     
  20. hallux macrumors 68020

    hallux

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    #20
    Care to cite your source for that?

    Here's a Google engineer explaining the USB-PD spec as it relates to charging Nexus 6P and 5x phones, both of which have USB 2.0 (spec sheet to show that:Huawei Nexus 6P - Full phone specifications) over USB-C: What are USB PD Power Rules? A lot of my readers have pored over the USB PD ...

    BTW, per USB-PD rules, even on a USB 3.0/3.1 port on USB-A (even if USB-C is on the phone/device end) you can still only charge at 2.4A max.

    BTW, ALL USB ports would "regulate charging", or at least NEGOTIATE charging. However, to get the FULL speed of USB-PD charging your device is capable of you MUST have USB-C ports through the entire chain, you can't just use any old USB port, even a 3.1 USB-A port.
     
  21. SteveJUAE macrumors 68000

    SteveJUAE

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    #21
    I think you will find it also has to be "Power Cable" USB-C which have 2 ratings 60w and 100w and not just any old USB-C cable

    However aevan was on the right track USB-C is the port how the port is configured is up to the OEM eg the MB USB-C is only USB 3.1 Gen 1
     

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