Having worked in the battery industry for 11 years, people who know me often say "I read or saw on the news about this great new battery that's been invented, where can I buy it?". I have to explain each time that it's only a theory or perhaps a prototype and the publicity is all about asking for money to develop it. There have been so many such as the one based on piss. Yes, you actually piss on it to make it work. Then there was the one that is the size of a CD case you can start a car from. Oh yes and the dodgy Russian who tried to kid us they could make one out of piezoelectric material which you embed in your shoe and when you walked it recharged. They never came to anything, surprise surprise!!