Charge retina MacBook via USB A to C cable and Digital AV Adaptor

Discussion in 'MacBook' started by jb8748, Jan 14, 2016.

  1. jb8748 macrumors newbie

    Joined:
    May 5, 2015
    #1
    Hello,

    Has anyone been successful charing the retina MacBook when using Apple's Digital Multiport AV Adaptor and a USB A to C cable?

    I've got an Anker 5 port charger and a new Anker USB A to C cable.

    If I plug the MacBook directly into the charger using the cable I get 12W of power - as expected.

    However if I plug the MacBook into the Digital AV Adaptor and then the charge cable into the adaptor I only get 2W of power.

    So it seems the negotiation for higher power is not working through the adaptor - but what I don't know is if this is true of all Apple's Digital AV Adaptors or if mine is just faulty.

    Interested to hear from anyone else what your experiences were if you've tried it.

    James

    [Note: when connected to Apple's charger via the supplied USB C-C cable the adaptor provides 23W power.]
     
  2. zhenya macrumors 603

    zhenya

    Joined:
    Jan 6, 2005
    #2
    I know that the adaptor needs to be powered itself so you lose something even with the standard charging brick. The only way you are getting 12w out of the Anker is if the MacBook is charging while totally shut down or asleep, otherwise there is typically only 3-6w left over for charging. After the additional load of the adaptor, there may only be those 2w remaining.
     
  3. jb8748 thread starter macrumors newbie

    Joined:
    May 5, 2015
    #3
    To be clear the 12W (or 2W) is the total reported to be coming from the power adaptor (according to coconutBattery) not the amount left over for charging.

    So, connected directly to the Anker charger the MacBook receives 12W - of which, as you rightly say, there's around left 6W for charging.

    But you're right about the adaptor power - I hadn't checked how much power it takes. So, MacBook direct to Apple's power supply gets 29W. MacBook to Apple's power supply through the Digital AV Adaptor only gets 23W.

    That suggests the adaptor needs at least 6W and probably accounts for all the losses from the 12W supply.

    Oh well, my hopes for a tidier desk and a free electrical socket will have to wait. :)

    Many thanks for your help.

    James
     

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