CO Alarm now…..

[Suregrip391]

Hi group,
Never had this issue till yesterday and today. The CO alarm started going off inside the camper yesterday afternoon. We had just returned from a trip three days prior (with no issues) and the camper is clean, empty, etc…..I replaced the batteries in it and it still went off alarming.

We brought the alarm inside the house and it stays quiet, all afternoon, night and day… I reinstalled it about an hour ago in the camper and now it’s going off again. So it’s not the alarm itself. Something in the camper causing CO?

What could cause the CO alarm to go off when the propane tanks are off and nothing is on or running? No furnace, no stove, etc……

I’m talking about the combo fire alarm/CO detector mounted high up by stairs/bed. Not the propane alarm down by the floor. Just so there is no confusion here.

Also black tank, gray tank, all empty and clean….

[rubicon327]

Do you have flooded lead acid batteries inside? Were they on charge via shore power and/or solar at the time? May be the hydrogen off-gassing setting off the alarm. The reason this happens is the sealed battery box really isn’t sealed.

[Suregrip391]

We are plugged in to shore at home and the batt was charging at 14.4v, it has always varied between 13.6 and say 14.5v in the past with no issues. Batteries can set off the CO also? My propane alarm has not gone off.

[rubicon327]

Yes, hydrogen can set off CO alarms. We never had false alarms until I moved batteries inside to make room for mini-split condenser on tongue. It would occasionally set off both our combo propane/CO alarm and combo smoke/CO alarm. Switched to lithium and it never happened again. Flooded lead acid batteries really shouldn’t be inside IMO. They should be in a truly separate vented compartment separated from interior space. AGM’s don’t vent under normal conditions and may be a middle ground if you are not ready/willing to switch to lithium. This is just my experience. You may have something else going on.

[Bill and Earline]

Here's how I'd approach it:

1) Disconnect from shore power and take down the CO detector

2) Make sure your trailer battery or batteries are full with the correct amount of water--assuming lead-acid.

3) Fully air out the trailer

4) Before re-connecting to shore power, put the CO detector back in place.

5) See if it goes off. If it does--either it's defective, out of date, or there is some outside source

6) Assuming it doesn't go off, take it out of the trailer. Before reinstalling the detector, plug into shore power and watch for amperage, meaning your battery/batteries are being charged by your converter/battery charger.

7) Once your batteries are charged and amperage drops down, and with the trailer aired out, install the detector. I can't imagine at that point that it would go off. It might then go off when the converter/charger kicks in later, and while it's going off, check the amperage to see if the converter is on, doing it's thing with the batteries. You might have to sit out there with a book or an iPad to watch all this or turn on something that would pull the batteries down a bit, causing the converter to kick in, but then you'd know.