Apple needs to fix this soon!
Using genuine Apple cable and USB port on my MacBook Pro (8.1) my ipad 4 will no longer charge after upgrading to IOS 8.4. Using same Apple USB to Lightning cable the same iPad works fine using an Apple charger. So the problem is not the cable - it is the fact that IOS 8.4 does not recognize an Apple MacBook Pro as being a valid power source.
Last week I upgraded my iPhone 6 plus from 8.3 to 8.4 and had a similar problem. USING A GENUINE APPLE USB TO LIGHTING CABLE my Iphone 6 plus went crazy when plugged into my Belkin 12v car charger. IPhone starts beeping and charging indicator flashed on and off rapidly. I thought there was something wrong with the Belkin charger and was about to replace it. BTW, my iPhone 6 plus charges fine with same USB cable when plugged into my MacBook Pro.
So Apple has some SERIOUS issues. 8.4 causes iPad not to charge with genuine Apple cable when plugged into MacBook Pro. And iPhone can't be charged using genuine Apple cable and Belkin 12v car charger. Not good news since Apple does not make a 12v charger and my iPhone 6 plus battery won't make it through the day without me plugging it into my car charger.
Apple - are you listening? Good! Looking forward to a fix.