Usually the data cable and the charging cable are run with four wires in the USB interface. The charging cable uses two wires with a relatively long outer metal contact, which are the positive and negative electrodes. The data cable is in the USB interface. Four lines, two of which are used for power transmission, so the data line can be used as a power line, but the power line cannot be used as a data line; use a multimeter to touch the two electric pens to the USB pin and the connection line to determine the power connection And data connection; the main function of USB is to transfer data and charge.
In theory, the USB charging cable only uses two wires for power supply (VBus) and ground (GND), and does not involve data transmission, so basically the USB charging cables are similar. But in fact, there are differences, because the cores of different quality USB cables are very different.
High-quality usb transmission lines, USB cables, the core is made of pure oxygen-free copper copper wire, and the quality of the lesser quality line is much worse, there are few copper wires in the core, and even some USB cables have only the core specifications One or two. If the quality of the cable core is poor, it will inevitably have an impact on charging, especially now that the output current is more than 2A power bank, poor quality wire resistance will be larger, and there is a risk of overheating and fire, and poor wire charging speed also It will be slower.
Different USB cables will affect the charging efficiency. The main reason is the wire core material, the number of wire cores, and the wire core specifications and length. For the same material and length, the more wire cores and the larger the wire cores, the faster the charging. When the wire core material, wire core number and wire core specifications are the same, the shorter the USB cable, the lower the charging loss and the faster charging.
