My iPhone 4 was down to about 3% so i plugged it into the (work) computer to charge and the charging symbol came up but it didn't go up from 3% and eventually ran out of battery. One thing I immediately noticed that was different when I first plugged it in was that the charging icon in the top right corner looked different, no longer the thunderbolt but a plug. I tried plugging it into the wall but still only the thunderbolt sign would show up. I tried the computer again and same thing; it wouldn't even recognize that it was plugged in, so I tried putting it into DFU mode, which then made iTunes recognize it, but it said I had to restore and download the latest iOS version, which I did, which didn't help. When I got home I tried plugging it in again, to the wall, with a different USB cord and it worked. Okay, problem solved, I thought... it's just a faulty USB cord. Well, a couple days later, it runs out again, so I plug it into the wall with the cord that worked and it no longer works. I tried using this same cord on my computer and still it doesn't work. I tried a bunch of other USB cords (I've accumulated a bunch over the years...) to no avail. I doubt it's an issue with the battery as I've only had this phone for a year, and it seemed to hold about the usual amount of charge in the last couple days that it was working again. I can't take it to the apple store. Any ideas? I'm thinking it's some sort of software issue, but have run out of ideas on what to do...