"BetaBatteries" Could Last for Decades
Because the tritium, a radioactive hydrogen isotope, is embedded in the battery's plastic, there's no risk of radioactive contamination from the device. And though they might be a hard sell to people looking to juice up their iPods or cell phones, BetaBatteries have clear applications in hard-to-service devices such as satellites and climate-monitoring equipment. An added benefit to BetaBatteries is their ruggedness, operating in temperature extremes from -148°F to 302°F.
Because the tritium decays so slowly, BetaBatteries can theoretically provide power for decades -- possibly outliving the devices they were meant to run.
Sources: Eurekalert, Roland Piquepaille's Tech Trends