Going further, I much prefer a sloooow trickle charge for my macpro. The more common case is a forgotten charger, or being in an airplane seat with only a USB-A available. That high capacity allows for charging the battery very quickly, even while using your Mac to the fullest. I'm bucking the 'gotta have 61 or 90 watts of power!' trend. MacPro USB-C can be charged with old style USB-A power sources Works fine, and doesn't 'drain your mac' as some people incorrectly guessed.

Someone did a nice youtube video on exactly that- charging your macbook via usbc from the regular old style usb sockets. Your best bet is to get a proper USB-C travel charger and hopefully the airplane will have the 12V sockets (car cigarette lighter port) rather than USB ports.Īs for the cables you need, if it's a USB-A port, just the USB-C to A adapter you already referenced and a USB-C cable which you should already have. As for the power draw, it will draw what it can - if the airplane only supplies 5W that's all you'll get. It will go faster if it's a 12W or 15W port, but still be quite slow. So, if you use a 5W charger (airplane, car, etc.), it will take forever to charge that MacBook (you'll drain battery if you attempt to use it while charging), but it will charge. Otherwise, it will simply draw the maximum which is no more than 12W (5V at 2.4A) If it can negotiate up (to a max of 20V) it will do so.

The default charge that comes from a USB-PD device starts out at 5V - this, coincidentally is the same voltage that legacy USB chargers output. The Type C ports on your Mac conform to the USB-PD (Power Delivery Spec) meaning it will negotiate for the maximum charge. I read somewhere that the new MacBook Air computers (the ones with USB-C) can be charged slowly from any USB source using a USB-C to USB-A adapter.

Charging cable for macbook air