I purchased my iPhone 5S in December. My 2013 Chevy Spark has both a built in USB port that acts as a power supply and I also have a power inverter with a 2A and 1A USB plug, and just for back up, a USB plug for the lighter.

For one month, I was able to charge my iPhone 5S using the provided cord that came with my phone in either the built in USB, the power inverter or when needed the USB plug when I used another vehicle for work. No problems charging.

Then this past Saturday, I got the notice, "this accessory may not be supported" and the phone refused to charge, (although the lightning arrow would appear next to the battery symbol and the phone indicated it was charging) using the provided USB cord in the power inverter. So I unplugged from the power inverter and into the cars USB port and the phone fully began to charge again. So I thought something was wrong with the power inverter.

The next day, I went to plug in my phone into the same cord, plugged into the USB port in the car and the message appeared again. Now I could not charge using this method. So, I brought the cord back in the house and plugged it into the white box and into the wall and the phone would charge.

Now today, again, the USB lighter adapter would not charge the phone with the same cord.

What strikes me is that the phone would charge until I received these notices (for over 1 month) and now I can no longer charge the phone via any USB port. I have a friend who has the same phone and is able to charge his phone using either of the 3 options given above with the same cord.