USB-C and powering devices USB-C and powering devices
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  1. #1

    TykeLike

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    Default USB-C and powering devices

    My new MBP charges via USB-C, it comes with a 60w adapter, as I usually have a few (one for home, one for the office and one to carry with me if I travel) I’ve been looking at Power Banks with Power Delivery so I have a portable source of power, but they only out put at 30w.

    Checking the average input on my MBP it only rarely goes about 29.7w with the occasional spike to 45/50, if I power it from a 30w device could it cause any damage, or just charger slower?

    Also I’m reading conflicting advice about cables, all seem to be ok for data transfer, but as a rule of thumb cheaper cables can’t do the full power transfer
    “Live a good life. If there are gods and they are just, then they will not care how devout you have been, but will welcome you based on the virtues you have lived by. If there are gods, but unjust, then you should not want to worship them. If there are no gods, then you will be gone, but will have lived a noble life that will live on in the memories of your loved ones.”

    ― Marcus Aurelius

  2. #2

    Prof Cunning @ Oxford Uni

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    Have you looked at Anker?

    Anker

    • Compatible with the new 12-inch MacBook, 2015 (USB-C cable needed),
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  3. #3

    TykeLike

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    Quote Originally Posted by WTFH View Post
    Have you looked at Anker?

    Anker

    • Compatible with the new 12-inch MacBook, 2015 (USB-C cable needed),
    That is the exact one I’m looking at, but I have a MacBook Pro which comes with a 61w power adapter where as the MacBook and MacBook Air comes with 29/30w adapters which is the same output as the Anker device you mention
    “Live a good life. If there are gods and they are just, then they will not care how devout you have been, but will welcome you based on the virtues you have lived by. If there are gods, but unjust, then you should not want to worship them. If there are no gods, then you will be gone, but will have lived a noble life that will live on in the memories of your loved ones.”

    ― Marcus Aurelius

  4. #4

    Prof Cunning @ Oxford Uni

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    Ah, it would help if I read the question more closely!

    Sorry, I can't help - it might work slowly. Going the other way is fine - I frequently charge my iPad Pro using ClientCo's Thinkpad power supply (65W)
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  5. #5

    Nice But Dim

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    Quote Originally Posted by SimonMac View Post
    My new MBP charges via USB-C, it comes with a 60w adapter, as I usually have a few (one for home, one for the office and one to carry with me if I travel) I’ve been looking at Power Banks with Power Delivery so I have a portable source of power, but they only out put at 30w.

    Checking the average input on my MBP it only rarely goes about 29.7w with the occasional spike to 45/50, if I power it from a 30w device could it cause any damage, or just charger slower?

    Also I’m reading conflicting advice about cables, all seem to be ok for data transfer, but as a rule of thumb cheaper cables can’t do the full power transfer
    It will work but at a slower rate, in thew same way that it does with phones. The USB Power Delivery standard allows the device being charged to negotiate the optimum power output with the charger. If the charger doesn't support that then the device defaults to a maximum safe power draw.
    "Being nice costs nothing and sometimes gets you extra bacon" - Pondlife.

  6. #6

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    Quote Originally Posted by DaveB View Post
    It will work but at a slower rate, in thew same way that it does with phones. The USB Power Delivery standard allows the device being charged to negotiate the optimum power output with the charger. If the charger doesn't support that then the device defaults to a maximum safe power draw.
    Cheers, that is what I thought, but I just wanted to double check!
    “Live a good life. If there are gods and they are just, then they will not care how devout you have been, but will welcome you based on the virtues you have lived by. If there are gods, but unjust, then you should not want to worship them. If there are no gods, then you will be gone, but will have lived a noble life that will live on in the memories of your loved ones.”

    ― Marcus Aurelius

  7. #7

    Still gathering requirements...


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    It will charge fine, albeit slower, but bear in mind that if you're using your Macbook while charging it, it may charge slower or not at all, depending how hard you're running your machine at the time.

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