I have the iPhone 5...I was down to about 8% when I plugged it in several days ago. There was no lint and no obstructions in the port whatsoever, and then I went to make a phone call. As soon as it started ringing on my end, I heard a "low battery" noise play through the earpiece (creepy noise, too - reminded me of the noise in the movie "Crank" when the guy was dying). I looked at the phone, and it had stopped charging, even though it was charging fine when I had just plugged it in. So, I decided to do what anyone else would do - switch cables/sockets/USB power adapters, etc. Nothing worked, except, RANDOMLY, and only once, my wife's Belkin Apple-Certified USB-to-Lightning cable. The next morning, I had full battery, but was unable to charge the following night, no matter what. What's even stranger is that, if you leave it plugged in all day, it trickle-charges about 1% an hour, but with no "lightning bolt" symbol visible. Apple is admitting it's a hardware issue, and has ordered a new iPhone 5 for me. In the meantime, I'm without a phone, and on a waiting list. Be aware, though...there's definitely some glitch they're going to have to address. It's not necessarily lint, a bad power adapter, nor a bad cable.