From an earlier thread which is now closed...
"We all seem to experience the alarm when plugged into shore power - a condition necessary for battery overcharging and outgassing to occur."
I am rekindling this thread to add some additional info and solicit some suggestions to prevent the hydrogen gas alarms.
I recently had a progressive industries converter installed. When I got the coach home, the coach batteries had been switched off for about a week and a half. As a result the battery was in need of charge.
fyi - I have 2 group 27 Trojan batteries.
I topped off all of the cells and connected to shore power. Not long after, the CO alarm went off.
The Progressive Dynamics converter has a pendant that indicates charge mode. At the time it was in "bulk" mode, meaning it was delivering max current to the batteries to shorten the charging time.
In an attempt to better ventilate the battery box to the outside I drilled a couple of additional holes near the top of the box at the end near the gas detector. I then resumed charging in bulk mode. Again it alarmed a short while later.
After resetting the alarm, I got a small hand held fan and propped it up in line with an existing 2 inch hole on the outside of the battery box. ( near the bottom with fan facing under the coach exhausting air from the box).
Now the bulk mode charging did not set off the gas alarm.
Next, I removed the fan and used the pendant to manually select "normal" mode charging which lowers the charge voltage and current to the battery.
Now no gas alarm.
So now I am in pursuit of a way to provide positive ventilation of the battery box. I ideally it would only be active when the charger is active. We don't need any more parasitic drains.
An additional footnote to this ventilation thing. I think it has something to do with the airflow near the battery box. If its fairly windy i think the holes in the battery box for the battery cables provide enough ventilation, but when the wind stops the hydrogen, which is lighter, than air can collect under the step and be released to the gas detector.
2011 Solera 235S