Looking to buy a watch with a durable band
Keep your robe handy.sweet dreams.
All of mine are hard wired but they do have a battery backup. I have not seen any that don't. Look again for the battery, I'm sure it has one. There are 7 in my house. If you goes off they all do. I had this happen a couple of times. The battery was dieing in one and it would go off setting off the others. I make it a point to change all of the battery's at the same time of course. Are yours also Carbon Monoxide sensors? Mine are. That was what concerned me the first time since like you I had no smoke.
Any standard 9 volt battery will work.
