One thing you can do is check battery health by observing the charging process with a power meter that supports charge counting. Another use case was when the

One thing you can do is check battery health by observing the charging process with a power meter that supports charge counting. Another use case was when the battery in my laptop was completely empty, which made it switch to some emergency charging mode that didn't like the normally fine USB-C power supply. I found that it did accept charge from an external battery, so I charged it using that for a while until it booted. I have a cheap device that costs about 2€ on AliExpress. It is not a cable but a little box.