Tried changing them since it's recommended that you do so every year. I'd written 12/15 on the batteries in them so they were definitely due but not beeping. Well, now with the new batteries they ARE beeping. I've run into this every time I have ever changed the batteries in these stupid f*I&*ing things. I've done the whole, unplug it, take out the battery, hold the button down for a long time, put the battery back in, thing and they still always beep. Am I the only one with this problem? At this point I'm pretty much ready to just gamble that our building is not likely to burn down.