iPhone charges really slow with MBA but not iMac

Akuratyde

macrumors regular
Original poster
Feb 7, 2011
249
1
I have an iPhone 4 that charges ridiculously slow when plugged into my Macbook Air (even when MBA is plugged in w/ full charge). I'm talking like 3-4 hours to fully charge. However, when plugged into my iMac at work it charges really fast, approx. an hour for full charge. Why is it different?
 

Applejuiced

macrumors Westmere
Apr 16, 2008
40,672
6,404
At the iPhone hacks section.
Different USB power output strengths.
On windows computers you can change that setting by using a program called ASUS AI Charger. Now I can charge my ipad 3 using my computers USB ports where before it displayed "not charging".
Not sure about macs.
 

Akuratyde

macrumors regular
Original poster
Feb 7, 2011
249
1
Right, I figured the USB ports were outputting power at different strengths. I'm curious as to why that would be the case though? It makes sense that they'd be the same across all Apple products but that's clearly not the case.
 

Applejuiced

macrumors Westmere
Apr 16, 2008
40,672
6,404
At the iPhone hacks section.
Right, I figured the USB ports were outputting power at different strengths. I'm curious as to why that would be the case though? It makes sense that they'd be the same across all Apple products but that's clearly not the case.
Configuration or maybe the power supply used is not that strong to power up everything. The mac air is very thin so they have to make compromises.
 

chambone

macrumors 6502a
Dec 24, 2011
969
24
Netherlands
Right, I figured the USB ports were outputting power at different strengths. I'm curious as to why that would be the case though? It makes sense that they'd be the same across all Apple products but that's clearly not the case.
No, it's not the case. My first gen MBA for example supplies 1 A though USB (because it needs to be able to power the optional optical drive) and my MBP only supplies 500 mA, charging my iphone at a slower rate. I wouldn't know about newer machines, but you can check how much power it gets in the USB section of system profiler or system info or whatever it's called when the phone is attached.