This reminds me of my post from a few months ago on a nuclear powered laptop. The BetaBattery would be different as it only creates a small amount of power but can do it for years.
I know that you can buy emergency signs lights that are powered by tritium gas that will last decades. These work by converting the beta radiation into photons via phosphour on the inside of the bulbs.
The Soviets used to use RTGs to power remote radio beacons but those turned out to be quite a problem for some people. As long as the BataBatteries are to be placed in areas that are very hard for someone to work at it with a hammer un-noticed these should pose little risk to the general public. Plus as its power source is a gas, and not a lot of it is in each unit, it would disipate quite quickly in the atmosphere. (like a drop of food colouring in a lake).
The battery’s staying power is tied to the enduring nature of its fuel, tritium, a hydrogen isotope that releases electrons in a process called beta decay. The porous-silicon semiconductors generate electricity by absorbing the electrons, just as a solar cell generates electricity by absorbing energy from incoming photons of light.
New ‘BetaBatteries’ May Provide Power for Decades