Review on 🔋 2-Pack Battery Operated FIRST ALERT CO400 Carbon Monoxide Detector - No Outlet Required by Rip Twin

Bought on March 30, 2017 and died just before the end of August. It started chirping like the battery needed replacing, so we put a new copper plate in. It was still beeping. We went outside to make sure it wasn't alerting us to CO levels. Battery empty, battery inserted, another new battery, third new battery, nothing changed. We ended up just removing the battery. Obviously this is the death knell for the expected lifespan of 7 years. Mine has the manufacture date "2016 Jun 07".