I would like to prevent my iPhone draining power from my MacBook Air while the laptop is not plugged in and relying on battery power. How would I do this? Note, there doesn't seem to be any "unpowered USB ports" on the MacBook Air, both of them seem to charge my iPhone even when the laptop is not plugged into a power socket...


I don't know if there is a software way to do that, but there is an hardware way:

  1. Use an unpowered USB cable (some company makes it, targeting audiophiles), might need an adapter to male lightning.
  2. Tape/Remove the power plugs on your USB cable.

Also, not exactly an answer to your question, but maybe to your use-case: Build a binary, then export it to iTunes, then upload via wifi. No debbuger and much less convenient tho.

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  • Using an unpowered USB cable or blocking the power wires could result in damage to the device. – Gavin S. Yancey Dec 9 '18 at 21:08
  • @g.rocket Blocking the power wires improperly might, but using an unpowered USB cable definitely would not. – Antzi Dec 10 '18 at 5:34
  • The iPhone was never designed to be connected to USB without the power and ground attached, so it could damage the lightning interface (or possibly the entire device). – Gavin S. Yancey Dec 10 '18 at 20:39

Assuming the only other reason that you would connect your iPhone to your MacBook Air other than charging would be syncing. As far as I know there is no way to disable to charging aspect although you can work around it by syncing over WiFi rather than cable. Hope this helps!

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  • 3
    Thanks, there's another reason, to test apps you are developing. – Victor S Jun 9 '14 at 21:57
  • Oh yeah, surprised I forgot that being a developer myself. Sorry about that. – rcobelli Jun 10 '14 at 1:14

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