What battery shall it be for you? Alkaline? Metal Hydrid? Litium?
Nuclear...?
I really wish this to become true, if only for havign Greens all over the place falling into deep depression and laughing about their mimimi.
https://www.notebookcheck.net/Westin....787535.0.html
Mind you, small reactors are in use since decades on SSN and SSBN submarines and Russian ice breakers.