My 6year CO alarm has been going off and it requires a special battery for replacement.I tried duracell but it still did not quiet it down. Calls for a Ultra alkaline battery, but have not seen any. ...
Problem is probably not the battery. Replace the CO detector. If battery is bad, it will just beep occasionally. If it is going off with full alarm, (AND THERE IS NO CO PRESENT). it has gone bad and needs to be replaced. For your safety, just replace it. Ours did the same thing. Replacement has't gone off since.