On a similar note: I have a second generation iPod nano. Years ago I took a spare cable for it and cut the data wires, hoping to be able to plug it into a compu

On a similar note: I have a second generation iPod nano. Years ago I took a spare cable for it and cut the data wires, hoping to be able to plug it into a computer to charge while still being able to play music. (I saw this tip somewhere online.) It worked with my brother's iPod classic (maybe 5th gen?), but not my nano; later I saw something on Adafruit about how the iPhone needed specific voltages on the data pins to charge, and I figured that was what was going on. But recently, I got a battery pack, which can output to microUSB, iPod, or some other things. It works with my iPod, the same one I had years ago. But the cables it came with have swappable ends, I think 2.something mm jacks. At any rate they only have two points of connection. Here's what it looks like: http://i.imgur.com/8TliS.jpeg http://i.imgur.com/8TliS.jpeg So, how does this work? As far as I can tell, this should be exactly the same situation as a standard USB-iPod charger with its data cables cut, but it's not behaving the same. It's possible I'm getting some details wrong, but can anyone shed some light on this?