Maybe the nice cable did something wrong to the iPad
December 17, 2015 1:07 PM Subscribe
Curiosity question: one of my charger cables won't charge my iPad but will charge my iPhone. What could be the cause?
I have two Apple 30-pin charger cables, an iPad 3, and an iPhone 4s (that I no longer use, but that's beside the point). Cable A charges both devices just fine, but the sheath is splitting at the head of the connector. Cable B is in great condition, but while it charges the iPhone fine, it refuses to charge the iPad. The iPad would just show "Not Charging" next to the battery icon. This is regardless of the charging source, whether it be the blocky iPad charger or my laptop.
I have caught Cable B charging the iPad maybe once, before the iPad throws up the "Not Charging" before full. Yes, I'm pretty sure it's actually not charging, rather than just saying that.
Both cables are Apple stock. So why would my iPad (or Cable B) pick favorites?
(This isn't a question of "should I get a new cable or repair the fraying one?", since I might get a newer iPad that has the Lightning port sometime in the near future anyways. But man, this cable behavior is so WEIRD.)
I have two Apple 30-pin charger cables, an iPad 3, and an iPhone 4s (that I no longer use, but that's beside the point). Cable A charges both devices just fine, but the sheath is splitting at the head of the connector. Cable B is in great condition, but while it charges the iPhone fine, it refuses to charge the iPad. The iPad would just show "Not Charging" next to the battery icon. This is regardless of the charging source, whether it be the blocky iPad charger or my laptop.
I have caught Cable B charging the iPad maybe once, before the iPad throws up the "Not Charging" before full. Yes, I'm pretty sure it's actually not charging, rather than just saying that.
Both cables are Apple stock. So why would my iPad (or Cable B) pick favorites?
(This isn't a question of "should I get a new cable or repair the fraying one?", since I might get a newer iPad that has the Lightning port sometime in the near future anyways. But man, this cable behavior is so WEIRD.)
iPads draw significantly more power than iPhones (as a side note, because of this you need to use an externally powered USB hub to connect multiple iPads to a single computer, otherwise they won't charge). Normally the cable wouldn't make any difference in how much power is being delivered to the device (that would come down to the power source, not the cable), but it might be damaged in such a way that it's not delivering full power to the plugged in device, which leaves it enough power for an iPhone but not enough for an iPad.
posted by Itaxpica at 1:26 PM on December 17, 2015
posted by Itaxpica at 1:26 PM on December 17, 2015
Best answer: but it might be damaged in such a way that it's not delivering full power to the plugged in device
Yeah, in my experience this is the natural life-cycle of the charger cord - the more that it has been handled (the longer it has been in use), the more breaks and surface oxidation in the copper fibres* accumulates and so the higher the internal resistance of the cord becomes, meaning less power for the device being charged, and this just increases over time until the device cannot be charged with that cord and the cord is thrown out and replaced with something new and the life-cycle starts again.
OEM cords are high quality (lots of copper fibre) and work much much better for much much longer. The ever-increasing resistance is much more rapid and noticeable on cheap cords.
The iphone throws up its "not charging" at a lower threshold of current than the ipad. Given enough handling, the iphone will stop charging on cord b too.
* I'm not sure of the mechanism by which the cords gain resistance with age of being handled, but damage to the fibres happens and seems to fit the bill, so seems like the obvious candidate to me.
posted by anonymisc at 2:06 PM on December 17, 2015
Yeah, in my experience this is the natural life-cycle of the charger cord - the more that it has been handled (the longer it has been in use), the more breaks and surface oxidation in the copper fibres* accumulates and so the higher the internal resistance of the cord becomes, meaning less power for the device being charged, and this just increases over time until the device cannot be charged with that cord and the cord is thrown out and replaced with something new and the life-cycle starts again.
OEM cords are high quality (lots of copper fibre) and work much much better for much much longer. The ever-increasing resistance is much more rapid and noticeable on cheap cords.
The iphone throws up its "not charging" at a lower threshold of current than the ipad. Given enough handling, the iphone will stop charging on cord b too.
* I'm not sure of the mechanism by which the cords gain resistance with age of being handled, but damage to the fibres happens and seems to fit the bill, so seems like the obvious candidate to me.
posted by anonymisc at 2:06 PM on December 17, 2015
Apples chargers use weird resistor values on the data lines of the USB cable to signify how much power can be drawn. There's a 1A(iphone charger) value, and a 2.1A value.
If the cable is messed up, or yea, there's lint in the socket and it cant tell then it'll throw that error.
And yes, i've seen them get to 80% and throw that error on several devices. It's pretty much always a bad cable. Like 99% of the time.
posted by emptythought at 3:16 PM on December 17, 2015
If the cable is messed up, or yea, there's lint in the socket and it cant tell then it'll throw that error.
And yes, i've seen them get to 80% and throw that error on several devices. It's pretty much always a bad cable. Like 99% of the time.
posted by emptythought at 3:16 PM on December 17, 2015
Response by poster: Ooo, I never thought about the internal resistance bit. Both cables are OEM though. Well, I have accidentally yanked on Cable B a few times because I forget it's still plugged in, so maybe...
Gonna try the lint-cleaning when I get home just to check :)
posted by curagea at 4:53 PM on December 17, 2015
Gonna try the lint-cleaning when I get home just to check :)
posted by curagea at 4:53 PM on December 17, 2015
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posted by norm at 1:14 PM on December 17, 2015 [5 favorites]