There are actually dedicated detector for detecting charger compatibility or faulty cable. And they are surprisingly not that expensive (rage from 20 to 40 usd

There are actually dedicated detector for detecting charger compatibility or faulty cable. And they are surprisingly not that expensive (rage from 20 to 40 usd depends on spec and vendor). Something like, test the cable and get a resistance of 0.6Ω ? Let's just toss it away. This will definitely fail the usb protocol and stop devices from working properly when charge at full speed. I actually found a few problematic cables with that. These are pretty hard to find out normally because they only fail when charges at full speed (cause the voltage to drop too much) and transmits data at same time. Or test a charger that labels fast charging but don't actually get any at all? The resistance changes a lot when you touched the cable(probably the connection between board and plug breaks)? Toss it away. They are broken or fake, why bother keep them.