AA Temperature and Humidity Sensor based made with Sonoff Zigbee Sensor

This is a custom-modified Sonoff temperature and humidity sensor that replaces the original coin-cell power source with an external AA battery holder. I am not affiliated with Sonoff in any way; this is a third-party modification and resale of a standard Sonoff device.

The modification is intended for environments where the original coin cell performs poorly, such as unheated garages, sheds, or other cold-weather locations. AA batteries provide significantly better capacity and cold-temperature resilience compared to CR2032-style coin cells, resulting in longer runtime and more reliable operation during winter months.

Key Features

Original Sonoff temperature & humidity sensor electronics

Custom-installed AA battery case (single AA)

Improved cold-weather reliability

Longer battery life versus coin-cell configuration

Ideal for garages, basements, workshops, and outdoor-adjacent spaces

Important Notes

This is a modified device, not a factory Sonoff product

No warranty or support from Sonoff applies

Modification is performed to improve real-world usability in cold environments

Battery Comparison (AA vs Coin Cell)

Battery Type Cold Weather Performance Runtime Maintenance Recommended

Lithium AA (Li-FeS₂) Excellent (down to ~-40 °C) Longest None Yes — Best Choice

NiMH AA (Low Self-Discharge) Good Medium Recharge required Yes (acceptable)

Coin Cell (CR2032 / similar) Poor (voltage sag in cold) Short in cold / Moderate indoors None No (for cold locations)

NiCd AA Poor–Fair Short High No