Loading iPhones (5 and 6) to fast - annoying beeping when no device is tuned.

It does what it should and that too very fast (felt better than with the original Apple power supply). BUT:
If the device has finished loading or no device is connected, the charger whistles in the socket in a shrill tone and audible even without much effort. Yes - I know - you should take power supplies after use in principle from the socket. But: If one hangs his smartphone before bedtime at the outlet, and then wakes up in the middle of the night and roars a whistle from the socket, which is already uncomfortable.

The power supply is convenient and cheap. But the "Whistle-feature" in conjunction with the not exactly handy size would let me tend in future to another model.