I purchased the First Alert 10-year battery life model P1210 in 2015 thinking I wouldn't have to worry about it for a long time. Ooops. Within one year, it died and the company sent a replacement. I installed the 2nd one (same model) on 6/25/16. Now, in November of 2018, this one is also dead. It started beeping at 3:15 AM, of course, so I took it down. I have to find a new smoke detector. Why advertise a 10-year battery that lasts 28 months before it dies? Piece of ***