I have a portable power bank and I can charge devices via USB on it. Is there an adapter to change a 3 prong charger to a USB, so I can plug my Mac into my power bank? A Mac air charger that can plug into a USB port would work as well.

2 Answers 2


Most MacBook use MagSafe charging which doesn't operate on the same voltage as USB - so the vast majority of battery banks that charge anything USB won't work. There are some inverters that would power the adapter using 120 or 240 VAC but those are quite large.

Only the new MacBook with USB-C connector is low power enough to charge over the new power delivery specification for USB 3.1 that generally is supported along with the change to USB-C connector. Any charging bank would need increased power than what is used to charge most any mobile devices made in 2015 and earlier.


Standard USB ports can not handle the load of power that a Macbook Air/Pro draws. So no, it is not advisable even if you could find an adapter. (Note that if you have the new ultrathin Macbook—not the Air or Pro—you can use a USB-C to USB2 cable to charge it from a power bank.)

You can get a special power bank (like this one) that can charge your Macbook Air via Magsafe.

  • Is that possible? The new MacBook uses the 20V lines on The USB-C. I'm not aware of a standard step-up circuit for USB-A to USB-C for power transferral. May 8, 2016 at 21:19
  • The special bank linked above inverts DC battery to 120 VAC and then powers the normal adapter. Those electronics are common. I have seen some attempts to provide DC directly to the magsafe adapter or DIY splicing of the wiring - but those are far less common.
    – bmike
    May 9, 2016 at 11:11

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .