Ted Yapo has designed a multi-year always-on LED replacements for gaseous tritium light sources.
TritiLEDs are always-on battery powered LED glow lights for general night-time marking use. Radioactive gaseous tritium light sources (GTLSs) are allowed in the United States in several consumer product categories, including watches, compasses, and gun sights, but general-purpose markers are considered “frivolous” and are prohibited. Levaraging advances in LED efficiency, battery capacity, and microcontroller technology, TritiLEDs run from 1 to 15 years depending on battery choice, and while larger than typical GTLSs, can replace expensive and sometimes illegal tritium lighting in a variety of applications (including the fivolous). Version 1.0 of the hardware and software is complete and released under an open-source (CC-BY-SA) license. Versions 1.1 and 2.x are works-in-progress and will be documented here as they are developed.
TritiLED – Multi-year always-on LED – [Link]