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tutux

macrumors member
Original poster
May 4, 2015
80
8
I noticed somethig with my usb c to usb a cable when using my ipad charger at home:

On the usb a side no choice to plug it.
On the usb c if i plug it with the brand of the cable on the top the charger deliver 2W. If i plug it with the the other way, it delivers 10W...

I tried it several times and now i understand why it was not charging completely over the night few times....

Now i can use my anker power bank to charge it while i'm using the laptop!

Can someone test it with another usb c usb a cable!??

If this is true i think this info is valuable for all of us!
 
Since USB-C is supposed to be reversible that is very strange.
Possibly some of the connections on the pins are bad on one side of the OP's connector? I'm not sure if that would end up having the result they are getting or not.
 
So one month later, still the case, I'm looking for a longer USB C - USB A cable.

So now my config is: Ipad charger + USB A- USB C cable + lighting cable. One charger for all, small form factor!

It takes longer to charge the macbook, but I charge it as I charge my iphone, overnight :)
 
How long does it take to charge your MacBook with the iPad charger? Is it the 10W or the 12W version?
 
10W charger, got it with ipad air 2.

And can't really say how long it takes as i'm not facing it when charging... i'll say 5/6 hours
 
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I have a couple of cheap cables from ebay and they both only charge in one orientation. I'd say it's probably simpler to just pass the wires through in a single orientation, so the cheap ones don't bother doubling the power lines. A little irritating, but I've been plugging in USB cables one way for years, I can live with it for some $3 cables. Good to hear the better ones don't do that though!
 
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I'm having a similar problem. My external drive won't mount on my macbook unless my adapter is right side up. Very strange
 
Not too strange when you think about it. These cables are adapting a connector that is unidirectional to one that is bidirectional. In order to make it fully functional in either direction, all of the pins coming from the usb-a port have to be duplicated on the usb-c side. Not surprising that these first generation, inexpensive cables aren't always fully implementing that.
 
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