A.M.
After moving in to our new home this spring ours started doing that. I mean come on they are new!! Well we even ended up calling the company that made them because we tried different batteries and they still chirpped all throu the house! I was going nuts...they would not stop even when we shut the breaker off that supplied power. The company told us to look in the battery door, it will contain a battery description and it will be either duracell or energizer. Well i did, there it was, carved into the plastic. DURACELL. I was like you have to be kidding me, you have to use a certain battery for the smoke/carbon monoxide detectors, well sure as sh*t, it worked!!