Using USB A to C to Charge?

Discussion in 'MacBook Pro' started by ipodlover77, Jan 1, 2017.

  1. ipodlover77 macrumors 65816

    ipodlover77

    Joined:
    Jan 17, 2009
    #1
    bought a couple of these.

    https://www.amazon.com/dp/B0119EIHTG/ref=cm_sw_r_cp_api_HgBAybDDDBM59

    We have a lot of iPhones and iPads in the household so we have a multitude of chargers lying around in each room. Will I be able to charge my MacBook with a iPhone or iPad charger? I know it'll be a lot slower but I just wanted to make sure that the voltage disparity won't damage the laptop.

    Also. I have one of those wall plugs that consist of theee wall plugs but also has two USB ports that you can directly plug in USB cables to. Same question. Could I plug in the USB A to C cable and charge my MacBook or will is the voltage too much and short out my comp?
     
  2. konnyaku macrumors member

    Joined:
    Dec 4, 2016
    #2
    It will work, it'll just be really slow. USB-C is a really flexible port, the voltage will just undergo a conversion which it's designed to do.

    USB charging blocks, adapters, cables all come with different amps/volts ratings but ultimately your charge will move at the rate of the slowest link in the chain.
     
  3. thesaint024, Jan 2, 2017
    Last edited: Jan 2, 2017

    thesaint024 macrumors 6502a

    thesaint024

    Joined:
    Nov 14, 2016
    Location:
    Republic of California
    #3
    I tried this with my previous XPS usb-c port and a 2.1a charger. No joy. I am speculating it's either that the cable was no up to spec or that these usb-c chargeable computers need a minimum amount of power to charge. I haven't tried with my MBP but am interested to know as well.

    Edit: I just tried it with a regular 2.1a charger and a usb-c to usb-a cable and holy s**t it works. It is quite slow. I get anywhere from 0 to 4 watts charging, which could take 10 to 40 hours to charge while using. Rough math says it will take 5-10 hours while sleeping or off. It's a far cry from the less than 2 hours the regular brick charges, but hey this will work in a pinch! Man I love usb-c.
     
  4. BarracksSi Suspended

    BarracksSi

    Joined:
    Jul 14, 2015
    #4
    Now I want a FireWire-to-USBC cable so I can use the leftover iPod charger I still have from 2004. :p
     
  5. thesaint024 macrumors 6502a

    thesaint024

    Joined:
    Nov 14, 2016
    Location:
    Republic of California
    #5
    Haha. That's probably a one watt battery (guessing) and would buy you about 15 minutes of usage.
     
  6. sentential macrumors regular

    Joined:
    May 27, 2015
    #6
    I've tried using a number of cables and unfortunately at best you'll get is a trickle charge due to the wattage at least for my 15", the 12" works just fine however.
     
  7. BarracksSi Suspended

    BarracksSi

    Joined:
    Jul 14, 2015
    #7
    I went ahead and dug out out -- the old charger is rated for 12V and 0.62A per the label, so that's, what, just over six watts?

    Should top off a 15" MBP in a couple days. ;)
     

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