USB Cables

Many thinks a USB cable is a USB cable but that is not the real truth. A USB cable can work perfectly with one device and when used with a Raspberry Pi it causes undervoltage and/or instability. The main culprit for USB cables used for powering Raspberry Pis is two folded. - Area, a lot of low quality cables uses cables with less area. - Length. The longer a cable the higher resistance it has = Higher voltage drop. The basic Ohms formula, V = I x R is applicable for the USB cables. V is the voltage drop over the cable and it is depending on I = Current and R = Resistance. The current is the current the Raspberry Pi consumes and the resistance is determined by, area of the conductor, the length of the conductor and the material used in the conductor. The current can be reduced by tweaking the OS and by what kind of hardware you have added. The resistance is a result of the USB cables quality and length. The quality is hard to measure as you need a ohm meter with milli ohm precision, but the length is pretty easy 😉 More about this topic: https://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity #177 Avoid Surprises: How good are USB cables and how can you test yours? https://www.youtube.com/watch?v=n70N_sBYepQ Your USB-C Cable probably SUCKS! Sooo is that Bad? https://www.youtube.com/watch?v=vKJWwBXRPuI