9

Always on USB ports will provide power to a device even when the laptop is shut down. Obviously this can be problematic for battery issues, but sometimes a user wants this capability all things considered.

Do the Macbook Pro offer this on any of the USB ports and if not is there any chance its wired and just has to be enabled?

2
  • 2
    FYI, as an alternative, you could try using a USB plug adapter to the end of the USB cable and plug the helicopter into the wall.
    – ckpepper02
    Jul 25 '13 at 15:31
  • i think my iPhone charger has that.
    – chovy
    Aug 5 '13 at 23:40
17

Apple has a support document on this topic.

http://support.apple.com/kb/HT4049

To meet requests for additional power from these Apple peripherals and devices, some Apple computers and displays can provide up to 1100 mA at 5 V through the port to which the Apple peripheral or device is connected. This power is available under certain conditions:

  1. An Apple peripheral device must be plugged directly into an Apple computer or display. Apple peripheral devices connected to hubs will not have access to extra power above the standard USB specification of 500 mA.
  2. Your Apple computer or display must be powered on and must be awake. If your Apple computer or display is asleep, all ports will provide a maximum of 500 mA at 5 V. If your Apple computer or display is powered off, no power will be provided.
  3. The port providing extra power is determined by the first Apple peripheral or device to connect to the Apple computer or display that requires power beyond 500 mA at 5 V. The remaining ports will continue to offer 500 mA at 5 V. Some Apple computer and displays may offer the ability to operate more than one USB port at 1100 mA at 5 V. On those computers, the second or third port is enabled when an appropriate device is connected.
  4. An Apple computer started up to Windows via BootCamp will not provide extra power.
3
  • ghoppe - that's the most awesome answer I've seen on which ports provide extra power while awake for things like iPad and iPhone charging. Power to charge iOS devices flows from the MacBook Pro if it goes to sleep with the device connected or if there is magsafe power and the device gets connected while the mac is sleeping (which actually wakes up the mac). Basically sleep power to USB depends on wall power, display lid up/down, and the order in which events happen.
    – bmike
    Apr 19 '11 at 17:28
  • 2
    Um, how does this answer the question? Extra power has nothing to do with sleep or "always on". Feb 2 '16 at 15:21
  • 1
    @PeterDavis I don't understand the point you're making. My answer, which references Apple's support document, clearly states that extra power will only be supplied if the device is awake.
    – ghoppe
    Feb 2 '16 at 18:45
5

my macbook pro 2014 has a always on usb on the right side. the left one will lose power when the screen shuts off.

1

Results on my experiment:

None of the 3 USB ports on my MacBook Pro 17 inch early 2011 will charge when the computer is off. All of the USB ports will charge A NON APPLE PHONE (HTC One V, the only device I tested) when the computer is asleep.

This is true both when the charger is connected and when the charger is not connected. Be aware that when the charger is not connected the charging power is coming from the laptop battery, depleting it.

See the comments to the answer by donlaur, below for information on charging Apple phones, which work differently.

0

My Macbook Air does this, I assume that the Macbook pro is the same. Have the lid already closed and plug it in.

Some PC's do this, but for laptops, it would be a good way to drain a battery. It depends on the power this thing drains if you need a low or high powered USB.

3
  • My (newish, less than a year old) Macbook Pro does not charge USB devices when off. I've been unable to find any preference that might enable it to charge them either. Very annoying since I don't turn it on very often, but would like to use it to charge my iPad. Jan 14 '13 at 15:29
  • 2
    My MacBook Pro will charge the iPhone while the lid is closed and it is sleeping. But that's not what you call "off" I guess.
    – GEdgar
    Jun 24 '13 at 17:39
  • In order to charge USB devices when your Mac is off/lid is closed the power adapter must be connected to your Mac.
    – Stan
    Sep 6 '13 at 5:09
0

Empirical evidence from my experiment:

None of the 3 USB ports on my MacBook Pro 17 inch early 2011 will charge when the computer is off. All of the USB ports will charge A NON APPLE PHONE (HTC One V) when the computer is asleep. I read that for Apple phones the Apple Company has set them to require that the computer be turned all the way on, not sleeping. Could someone who has an Apple phone please test this?

1
  • My MacBook Pro 15" 2014 will charge my wacom tablet and bluetooth headphones and iphone when sleep with the lit shut but not when shutdown. Oct 31 '14 at 3:01
0

The USB ports on any relatively recent MacBook will provide power while the computer is asleep, but I doubt they would while it is shut down.

You must log in to answer this question.

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