The Electric Viking just posed about the Betavolt nuclear battery. I disagree that this will end up in a car in your lifetime but it is real and it is interesting. It uses Ni-63 as a beta particle source. As that isotope has a 100 year half life, it is reasonable that it could last for 50 years. But, I wanted to know more about the science.
An article in Science Digest seems like a good compromise between decent technical information and something you can understand. The specific battery they are talking is not what Betavolt is producing but it explains how using Ni-63 as a source of low-energy beta particles works. It’s interesting and what I would expect in our lifetimes are TV remotes and possibly cellular phones that don’t need a battery change .