USB C 15inch 2017 MacBook Pro not delivering enough power

Discussion in 'MacBook Pro' started by jgbr, Aug 19, 2017.

  1. jgbr, Aug 19, 2017
    Last edited: Aug 19, 2017

    jgbr macrumors 6502a

    Sep 14, 2007
    Has anyone experienced a scenario where you are hitting your CPU and GPU so hard that charging is suspended?

    I've noticed that when I was converting some video files Mac OS reported the machine had switched from charging to power adapter plugged in and not charging.

    Thinking I had one of the dreaded battery problems, I messed around with cables, ports etc to discovered it only did this when the CPU and GPU were maxed out.

    In some cases where many USB C devices were also plugged in, it had started to drain the battery as well. [I seem to remember some of the older MBP's also having this issue?]

    I noticed the CPU was pulling up to 37W and GPU up to about 33W. [I can only imagine how much more if you have SSD's, devices, USB key fobs and all that plugged in too].

    It also seems when their is 'spare power' to charge, the charge time changes.

    To verify this, when the machine went back to 'normal operations' and finished exporting video , high speed charging was resumed.

    I'm starting to think that 87W adapter is simply not enough...considering USB C is rated to 100W.

    I did wonder if a dock would solve this by anything plugged in using its power supply and the adapter that comes with machine used solely for powering the machine.

    Any thoughts?
  2. Brookzy macrumors 601


    May 30, 2010
    This has been the case for a long time with many generations of 15" MacBook Pro.

    If you just ignore it, you're very unlikely ever to notice it impact functionality. It's pretty hard to get the power consumption to exceed 87W constantly for an extended period.
    Good idea. :)

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