Originally Posted by travelin texans
Have never had a CO/LP detector with 9 volt battery power, all have been hardwired to 12 volt rv system. Typically the beeping is as mentioned low battery or out of date detector.
Ours is strictly a CO detector and was original to our rig. It is powered by a 9 volt battery. There are 12 volt hardwired units also, in addition to combination units that have LP and CO detectors. Regardless of how they are powered, if the sensor or sensors go bad, there is nothing you can do to fix these except to junk them and install new ones. I have replaced the CO detector once, probably will be due for a new one soon, the smoke detector I replaced a couple years ago, installed one of those 10 year units that you just replace when they signal end of life, and the LP detector I just replaced in January while at Quartzsite, and this was the second replacement.