That may actually be not that far away: >first nuclear battery can deliver 100 microwatts of power and a voltage of 3V >plans to produce a battery with 1 watt

That may actually be not that far away: >first nuclear battery can deliver 100 microwatts of power and a voltage of 3V >plans to produce a battery with 1 watt of power by 2025 https://www.independent.co.uk/tech/nuclear-battery-betavolt-atomic-china-b2476979.html https://www.independent.co.uk/tech/nuclear-battery-betavolt-...