Charge from a desktop USB?

Discussion in 'MacBook' started by GrantMeThePower, Apr 22, 2015.

  1. GrantMeThePower macrumors regular

    Joined:
    Apr 12, 2011
    #1
    Hi guys,

    Can you charge the new Macbook from a computers' usb port (a to c cable)? I know they say you can charge from a portable battery pack, but what about from my imac or mac mini?
     
  2. newellj macrumors 601

    Joined:
    Oct 15, 2014
    Location:
    Boston, MA, US
    #2
    Pefect forum ID for this question. ;) The collective belief is that you'll get a trickle charge from a 5.2v USB port, enough to slowly charge if the rMB is off, but not enough to charge if you'r using it. The Apple AC adapter is 29W at 14.5V.
     
  3. willydimes macrumors regular

    Joined:
    Jun 8, 2014
    #3
    I honestly don't know enough about the thunderbolt display so excuse me if a stupid question. I know it USB ports don't charge at 29W or anything but would it charge the rMB faster than a normal 5v say for topping off a charge
     
  4. JTToft macrumors 68040

    Joined:
    Apr 27, 2010
    Location:
    Aarhus, Denmark
    #4
    - Probably not. I don't know what your intended use is, but just be aware that you can't use the Thunderbolt Display with a Retina MacBook, since it lacks a Thunderbolt port.
     
  5. willydimes macrumors regular

    Joined:
    Jun 8, 2014
    #5
    Yea I know, I was saying use the USB port to charge
     
  6. fatefulwhisper macrumors regular

    Joined:
    Jul 24, 2008
    #6
    I'm very glad you brought this up, because I never thought about this, but was curious, so I went ahead and tried this. I had already bought a usb cable (c<->a) from google, and I don't actually have a desktop, but I do have a MacBook Air.

    My rMB was at 85% when I tested this; the MacBook Air was at 99% battery (although having it plugged in would be the same thing, since it will draw power from somewhere). After plugging it in, it said that it would take 2:21 until it was fully charged.

    So, to answer your question, yes, you can charge the new Macbook from a computers' usb port.
     
  7. 5errated macrumors member

    Joined:
    Sep 17, 2012
    #7
    it's only a matter of time until there are usb power banks that support usb 3.1 / type-c for some high watt charging. an 18,000 mAH bank would potentially give you 36 hours of total laptop screen time. (could be a hair less given the mAH rating is usually of the battery inside, not accounting for voltage drop and power lost at the dc to dc converter)

    but still, this is a big deal. i hate how people got all butt-hurt about it only having one port but are missing the point on how awesome it is. i think they should've included ONE dongle... a splitter. one for charging, and the other to use while you're charging. that would be plenty for me and most users.

    need to print? airprint. need to move a file? airdrop. or cloud drive. or home network share. i never used the usb ports on my 15" retina. only time i recall using it was to install windows because it forced me to use a thumb drive
     
  8. GrantMeThePower thread starter macrumors regular

    Joined:
    Apr 12, 2011
    #8
    Sounds like the answer is "yes you can...but it's really slow!" haha

    Thanks guys!
     
  9. mikeray macrumors regular

    Joined:
    Jan 17, 2006
    Location:
    Brooklyn, NY
    #9
    Just a thought: You could use a Y-cable to speed up the time a bit. Something like this:

    [​IMG]
     
  10. GrantMeThePower thread starter macrumors regular

    Joined:
    Apr 12, 2011
    #10
    That just doubles the draw? If that is how it works...clever idea!
     
  11. mikeray macrumors regular

    Joined:
    Jan 17, 2006
    Location:
    Brooklyn, NY
    #11
    Yeah, it doubles it! You have to do this if you use an external HDD with the Nintendo Wii U.
     

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