I was the sole firmware engineer on this sensor across two hardware generations. I joined when the first ESP32-C3 prototypes (V1) had been fabricated, and through systematic power profiling I found that the platform could not be pushed past a roughly 9-month battery life. That was below the product's hard 1-year requirement and made V1 effectively unsellable. I made the technical and supply case for moving to a Nordic Semiconductor nRF52832, rebuilt almost the entire firmware from scratch, and worked closely with the hardware team on the V2 design. The shipped sensor is rated for 3+ years, and units installed in late 2022 are now 3.5 years in with good remaining battery capacity. This provides field-backed evidence that the battery life will likely be at least 4 years.
