Jim, Here is an article describing the challenges associated with betavoltaic batteries. The recent buzz over the 30 year battery, while intriguing, is overly optimistic. As stated in the article I linked to, betavoltaics currently have low efficiency, require heavy shielding, and the energy absorption media tends to degrade due to the high energy bombardment. I think it would be great if they could overcome these issues, but it looks like it may be 30 years before we see anything like a 30 year battery. – Mark D. in Utah Mr Rawles, Firstly I would like to say that after …