Headphone charging UX 🎧

My wireless headphones have a battery that lasts for ages. Hooray! But eventually it goes flat, and then two things happen.

• I have to find the right USB cable. For some reason it's picky and they don't all work.
• I have to look up how to tell when it's fully charged. Am I waiting for the light to flash, or go out, or stop flashing? What I really want is for the state to change, but that would mean remembering to look at the light as soon as I plug it in. I never remember.

And while I was typing this the light went out. That must be it.