Avalanche Energy has secured a $5.2 million contract from the Defense Advanced Research Projects Agency to develop next-generation radioactive batteries designed for use in space and other demanding environments. The project is part of DARPA’s Rads to Watts program, which aims to significantly improve the performance and practicality of nuclear battery technology.
Radioactive batteries, also known as radioisotope power systems, are not a new concept. They have been used in applications such as deep-space missions and medical devices, where long-lasting and maintenance-free energy sources are required. For example, NASA has deployed such systems in spacecraft and planetary rovers. However, their relatively low energy density has limited broader adoption.
The new initiative seeks to address this limitation by developing batteries capable of delivering more than 10 watts per kilogram, a significant increase compared to traditional radioactive batteries, which typically produce around 2 watt-hours per kilogram. The goal is to create compact power sources capable of running laptop-class systems for extended periods, potentially lasting months without recharging, according to an official press release by Avalanche Energy.
Avalanche Energy plans to achieve this through the development of solid-state, microfabricated cells known as alphavoltaic devices. These systems convert the kinetic energy of alpha particles emitted by radioactive materials directly into electricity, similar in principle to how solar panels convert sunlight into power. By improving the efficiency and durability of these cells, the company aims to create more practical and scalable nuclear battery systems.
The batteries are being designed with extreme operating conditions in mind. Space environments expose electronics to high radiation levels, temperature fluctuations, and mechanical stress, all of which can degrade conventional power systems. The DARPA-backed project includes testing under such conditions, using particle accelerators and active isotopes to evaluate performance and resilience.
The development effort involves collaboration with multiple research institutions, including universities and national laboratories. These partnerships are intended to support both the engineering and materials science challenges associated with building durable, high-efficiency devices.
Although Avalanche Energy primarily focuses on fusion energy, the company views this project as complementary to its long-term goals. The technologies developed for alphavoltaic systems, particularly in radiation-resistant materials and direct energy conversion, are expected to contribute to future fusion-based power systems.
The company has already demonstrated early-stage fusion technology but has not yet achieved net-positive energy output. The DARPA contract represents a step toward building the technical capabilities required for portable and scalable energy systems, both for space missions and terrestrial applications.
If successful, the project could expand the role of nuclear batteries in areas where long-duration, reliable power is critical, including defense systems, remote infrastructure, and deep-space exploration.
