The batteries were recently dying on the smoke detector in the flat. I tried to take it down but one leg on my stool is slightly shorter than the other and so I didn't try very hard. The beep is quite loud on it but I got used to it and started ignoring it because I thought the batteries would die soon enough. Not the case. I didn't really notice it after a week or so but apparently the sound was very annoying to my neighbours. I arrived home the other night to find a note taped to my door. As a result of this, I tried to take it down again. I pulled it off the ceiling and got the battery out of it. But it kept beeping! It's like the undead! There seems to be a back up battery in there. I wrapped it in a towel but it still continues to beep in the drawer. At least it is quieter. I am now seriously thinking about replacing the battery before I move out and gluing it back up on the ceiling. No guarantees though,ha ha.