Nest Protect Smoke & CO Alarm (Battery)

The Nest Protect (Battery) is Google's WiFi-connected smoke and carbon monoxide detector featuring Split-Spectrum Sensing that detects both fast-burning and smoldering fires. This battery-powered version installs anywhere without wiring, using six AA lithium batteries with approximately 5-year life. The detector connects to your WiFi network for smartphone alerts and Google Home integration.

The Split-Spectrum Sensor uses two wavelengths of light to detect different fire types, while the electrochemical sensor monitors carbon monoxide levels. Pathlight illuminates your path when you walk underneath at night. Steam Check algorithm reduces false alarms from bathroom steam. Voice alerts announce the type and location of danger rather than just beeping.

The Google Home app provides emergency alerts, heads-up notifications before full alarms, battery health monitoring, and safety checkups verifying all sensors. Multiple Nest Protects interconnect wirelessly—when one detects danger, all alarms sound. Note that Nest Protect doesn't natively support Apple HomeKit, though third-party bridges like Starling Hub enable integration. The detector must be replaced after 10 years per safety certification requirements.