How phone batteries measure the weather
This is the story of the most surprising thing we have yet discovered at OpenSignal. Eighteen months ago we began gathering data on battery performance from our Android app - the metrics available on Android include charge level, voltage and battery temperature.
Context & Ripple Effects
Batteries have been treated as a benchmark subject in mobile coverage — LAPTOP Mag ranked handset endurance back in August 2010, and researchers spent 2011 putting smartphones on a power diet to stretch charge life. OpenSignal's finding flips that framing: the battery temperature, voltage and charge metrics its Android app has quietly gathered for eighteen months double as an environmental dataset, because handset thermals track ambient conditions.
The scale is what makes it more than a curiosity. With Kantar putting Android at 51.7% of US smartphone sales through April 2013 and Canalys estimating it powered a third of all mobile phones shipped in Q4 2012, OpenSignal's app sits on one of the largest fleets of temperature sensors ever deployed — syndication to GigaOM and TechHive suggests the observation landed well beyond its own audience.
First-order effects
- OpenSignal gains a second product line at near-zero marginal cost: every Android user running its app becomes a passive weather-reporting station, extending the company beyond network-signal mapping.
Second-order effects
- Meteorologists and weather-data buyers gain a dense ground-level sensor layer no station network can match in granularity, pressuring incumbents to treat crowdsourced handset telemetry as a legitimate input rather than noise.
Third-order effects
- If the pattern holds, the smartphone installed base becomes ambient infrastructure — any app with sensor access is a potential data broker, which sharpens the platform-trust questions already raised by Android's position as the sole actively targeted platform for mobile malware.
The trend: The smartphone is evolving from a device people carry into a distributed sensing platform, where the installed base itself — here via Android battery telemetry — becomes the infrastructure for whole new data markets.