Here is a camera I learned about recently on a dashcam forum.
It does have an internal battery good for 1.5 hrs max.
Impressive part is that it has a Sony Exmor sensor, and WiFi, and sells for just $120.
https://www.gitup.com/cameras/78-git...on-camera.html
I use a Replay XD Prime X on my helmet, which is just a small black cylinder that most people mistake for a light.
They have been out of production for several years.