I bought this 3GS when it first came out. So it's kinda old. Ever since I updated to iOS 6, there have been a few times when it just suddenly shut down in the middle of something. Sometimes I had to just restart it, and other times I had to charge it for a while to turn it back on, even though there had been at least 30% battery left when it crashed. Yesterday it died again, again with the battery still 30% or so left. My USB cable is 3rd party, but it had been working just fine, so I don't think it's the problem. I can't get to a Genius Bar and don't want to mail this for repair, so I'm trying to figure out if I can hopefully fix this on my own. So my question is, have you guys heard of cases of 3GS batteries suddenly dying? I had always thought that iPhone batteries slooooowly give out in a more "noticeable" manner. I'm basically wondering if putting in a new battery might be the fix. Thanks for your comments in advance!