BFL13 wrote:
A trailer has no engine so you don't have a CO detector either :)
The LP alarm will sound if the DC 12v power to it gets low. Usually from low battery when not on shore power. After the power gets too low to run the alarm at all, it does nothing till it gets its 12v back.
A truly dead battery may come back to life but it will not be the same good as new!
No, it became code here for all RV's to have a CO detector in about 2006 (give or take). I suspect it was because our furnaces can emit it and there have been many deaths associated with CO coming from generators and other vehicles idling nearby.