SaferProducts incident

Failure type

Fire / ignition

Incident narrative

SaferProducts.gov consumer incident report 20231115-526A6-2147343997. Severity: Incident, No Injury. Product: Nest Topaz-2.7 (Nest Protect Gen 2, Smoke and CO2 Alarm, Battery Powered, see 2nd Gen on this page: https://support.google.com/googlenest/answer/9232605?hl=en). Incident: Google Nest Protect Gen 2 Smoke/Carbon Monoxide alarm battery overheating. Second time this has happened in my Nest Protects, I have 7 of them. November 2022 issue: Nest Protect reported no issues in regular testing since installed in 2019. Suddenly, it loudly chirped and the app popped up with a low battery warning. I popped it off the ceiling and opened up the battery compartment to swap the batteries and was greeted by the faint smell of what I can only describe as hot plastic/burning rubber. I pulled the batteries out and one of them was BURNING hot. Like boiling water hot - could barely touch it. Battery took hours to cool down outside. Google replaced the device through their safety program. November 2023 issue: Same exact issue, different device. Contacted Nest and am awaiting contact from the safety team again. I used a thermal camera and the hot battery, an [REDACTED] Ultimate Lithium AA battery, was around 150 degrees. Other batteries in the device and the other 6 devices I checked as a precaution were only 70 degrees. Extremely concerning since this is a fire detection device and this could have the potential to cause a fire if the battery got hot enough. After having this happen twice to me and seeing many reports on Google Nest's forum, I felt it appropriate to report to CPSC. See this page for lots of similar reports through the forums: [REDACTED]