Sparkfun used to carry something similar: https://www.sparkfun.com/products/retired/14773 https://www.sparkfun.com/products/retired/14773 Hackaday also have a

Sparkfun used to carry something similar: https://www.sparkfun.com/products/retired/14773 https://www.sparkfun.com/products/retired/14773 Hackaday also have a post about making your own: https://hackaday.com/2016/12/01/make-your-own-nuclear-battery/ https://hackaday.com/2016/12/01/make-your-own-nuclear-batter... Obviously tritium will not give you 50 years of power, but it also won't cost anywhere near as much.