As you might expect, the build quality of these counterfeit Lightning-to-USB cables is light years behind that of the original. However, the folks at Toxic Cables – the ones who got to take a knock-off apart, say that the particular kind they ordered actually worked just fine: their device would connect to a computer, sync and charge without any problems. The only issue with the cable was the presence of noise in the connection due to the lack of any shielding whatsoever. Something had to give in order to make the accessory so cheap.
But just because this particular Lightning-to-USB cable worked, there is no guarantee that other fakes will. Keep that in mind if you ever plan on buying a knock-off.
source: Toxic Cables via Apple Insider