Good USB Cable ?
Most of us will have a few USB data and charging cables lying around but they don't usually work well with all devices. Most USB cables might look alike from external appearance but they might be different inside. And that is probably the reason why some USB cable are unable to charge your device while another can.
Regarding micro USB, there are 5 wires inside the USB 1.0 and USB 2.0 cables. The 5 wires are:
2x 28 AWG data lines
2x 20 - 28 AWG power conductors
1x drain wire
Those 5 wires are connected to the 5 pins in the micro-USB connector.
Besides, there are some printed codes on USB cables, such as "28AWG/2C and 24AWG/2C" or "28AWG/1P + 24AWG/2C". The first code is normally the specification of the data signal pair, which is normally 28AWG. "2C" means 2 conductors, and "1P" or "1Pr" means 1 pair. "2C" and "1P" are basically the same.
The second part of the code is the specification of the power distribution pair. According to standard, USB wire could fall between 20AWG and 28AWG. The minimum requirement for USB cable is 28AWG, and the lower the AWG number the better. This is because lower AWG wire is thicker, and therefore the electrical resistant is lower. We should also note that the longer the length of a USB cable, the higher the resistance. So a long cable would require a thicker wire if it wants to allow the same maximum current as a short cable.
In all, charging with a "28AWG/1P + 24AWG/2C" USB cable is normally faster than a "28AWG/1P + 28AWG/2C" cable.