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View Full Version : Can a MBA charge a phone via usb when it is off?




theoretician
Nov 4, 2010, 02:13 PM
Am looking into the new MBA. Some laptops (eg toshiba) have a powered USB port which can charge external devices even when the laptop is off.
Can the new macbook air do this?
Can it do it in sleep mode?
Can it do it with either usb port?
Also do you know what the maximum current draw on the USB ports is - my phone needs more than 500mA to charge when switched on.
Thanks



SashaFierce
Nov 4, 2010, 02:41 PM
Unfortunately it will not charge anything while asleep. I had my iPhone 4 plugged in and as soon as I shut the screen it stopped charging.

theoretician
Nov 4, 2010, 02:45 PM
That is bad news. So I'd have to take another power supply with me when travelling....
How do you mac users cope with all the extras you need to carry around?

maflynn
Nov 4, 2010, 02:48 PM
The ports are not energized when the laptop is asleep or off, so you'll not be able to charge anything while in that state.

LinkMx
Nov 4, 2010, 03:55 PM
How do you mac users cope with all the extras you need to carry around?

The same way PC owners do since most laptops won't charge any usb device when they're sleep or turned off.

jamone13
Nov 4, 2010, 03:59 PM
Am looking into the new MBA. Some laptops (eg toshiba) have a powered USB port which can charge external devices even when the laptop is off.
Can the new macbook air do this?
Can it do it in sleep mode?
Can it do it with either usb port?
Also do you know what the maximum current draw on the USB ports is - my phone needs more than 500mA to charge when switched on.
Thanks

Simple, just hit the screen brightness key to turn off the backlighting, and leave the Air running. Why carry extra stuff with you?

robby818
Nov 4, 2010, 04:05 PM
Even if it could, I wouldn't do it. Constantly using a USB port on your laptop for charging devices is asking for trouble. Burning out a port is a possibility and then you are talking about a very expensive fix.

astrorider
Nov 4, 2010, 04:06 PM
Unfortunately it will not charge anything while asleep. I had my iPhone 4 plugged in and as soon as I shut the screen it stopped charging.

Are you sure this happens even when the macbook air is plugged in? My previous experience with apple laptops was:
if plugged in and alseep, usb ports provide power
if not plugged in and asleep, usb ports do not provide power

The macbook air might be different, though.

theoretician
Nov 4, 2010, 05:01 PM
The same way PC owners do since most laptops won't charge any usb device when they're sleep or turned off.

Not true in my experience. My last two laptops (sony vaio and lenovo) will charge in sleep mode and the lenovo will when switched off as well. Toshiba's will also charge when switched off.

Even if it could, I wouldn't do it. Constantly using a USB port on your laptop for charging devices is asking for trouble. Burning out a port is a possibility and then you are talking about a very expensive fix.

Seems unlikely on the above machines which have this as a design feature. Have never owned a Mac so perhaps they can't handle charging through the usb.

Are you sure this happens even when the macbook air is plugged in? My previous experience with apple laptops was:
if plugged in and alseep, usb ports provide power
if not plugged in and asleep, usb ports do not provide power

The macbook air might be different, though.

Would make sense not to power the usb when there is no external power - so I'd be interested if someone can really confirm that the new macbook air cannot do this when plugged in.

wingnut8
Nov 4, 2010, 05:13 PM
I charged my phone via USB while the computer was asleep and plugged in the other night.

freitas
Nov 4, 2010, 05:17 PM
Yes it can.

Just confirmed with 11.6 MBA with both the iphone and ipad. 11.6 behave like the MBP and will charge the devices when supplied power by the AC adaptor. Albeit charging the ipad may take a while.

koobcamuk
Nov 4, 2010, 05:27 PM
My MBP charges my phone when it's asleep and plugged into the mains.

Curious about the air...

theoretician
Nov 4, 2010, 05:39 PM
Excellent - thanks for checking that out.

iag48
Jan 19, 2011, 02:59 AM
Freitas,

Does your macbook air 11.6 charge the iphone if plugged from the right hand side USB port?

Just asking because my air is not recognizing, nor charging, my iphone while being plugged into the right side USB port.

telemark948
Jan 19, 2011, 10:38 AM
MBA 13"

Charges my Phone 'Nokia E72' from both ports while plugged in and lid closed asleep. It does not charge while on battery with the lid closed, It stops charging approximately 5 seconds after the lid is closed. As soon as you plug the power lead back in keeping the lid closed it continues the charge. Thats as far as I tested..