Running the onboard generator while you sleep can be a VERY bad idea, unless you have some means (Genturi or similar) to run the exhaust well away from the living area!
You could wake up very sick, or possibly even not wake up at all!
I certainly would not do it in my coach, and I am fairly certain the generator exhaust system is in good shape, but I don't trust electronic gadgetry well enough to bet my life that the carbon monoxide detector will work!
The very first Class A that we bought had a Group 8D battery for the coach. The outside temp was about 35 degrees, and the thermostat was set for 60 degrees. The battery went dead at 3 o'clock in the morning! I had to get up and start the engine to get enough power to start the generator! that was not a fun night!
What made it better was that the fishing in that Montana mountain pothole lake was GREAT!!