I have a 10 foot USB extension cable on my 2.1ah 5v Apple USB charger for my iPad mini retina. ... If 20 AWG, then the power lost is 0.44 watts, if 24 AWG then we lose 1.1 watts ...

A: Don’t assume every extension cable is great at its job. My first reaction is that your cable is to blame. While you should theoretically be able to use up to a 5-meter long USB cable with ...