I'm having the exact same problem!
It's doing my nut in and i almost threw my iPhone through the window as a result of this frustration.
I've never had any problems charging my iPhone 5 before, I got it in January so its not even that old.
Now after updating it, it won't charge at all.
I've tried it in every single socket in the house, 2 different macs and one computer. Nothing seems to be working.
So I now have a dead phone, which I need as I've just moved half way down the country and have no idea the surroundings so rely on my phone a lot!
When phone gets plugged into a mac I get the following message:
"Because a USB device was drawing too much power from your computer, one or more of your USB devices have been disable
To prevent damaging your computer, the USB device drawing too much power has been disabled. Other devices may have also been disabled. When you disconnect the device drawing too much power, your other USB devices will be enabled again."
Theres nothing else plugged into the mac and the iphone is off so theres no power anywhere!
I'm baffled!! Anybody manage to sort theirs out?