The current state of the art is permanent batteries. The tech has been in use in black ops for at least two decades. I doubt it will be allowed to be commercial

The current state of the art is permanent batteries. The tech has been in use in black ops for at least two decades. I doubt it will be allowed to be commercialized for at least another two decades. Probably not even in our lifetimes. It would be too disruptive to the world slavery system.