I've had these cords for about 3 months now and use a 3ft cord to charge my phone every night. I keep it on my desk so it never moves, spins or unwinds. But now it only charges when the Lightning connector is installed one way. If I swap the plug, it won't charge. This happens every time I charge my phone at night. Guess correctly and the phone will indicate charging, if you get it wrong the screen will remain blank until you flip the plug. Expect a cable you can take with you and put in your backpack, this isn't what you want, it won't last very long.