Mrs Frog has a two car garage. On the ceiling was a 5 year old CO monitor, sealed battery unit, and 10 year warranty. Recently it started beeping. It wouldn't reset, so I figured it was dying an early death.
I went and bought a new one and installed at the same place on the ceiling. This one has a recorded voice that repeats what kind of alarm is triggered in between the alarm sounds. Around 2 in the morning the little lady wrapped in plastic starts yelling "Carbon Monoxide Alarm". I stagger into the garage scratching my head, for there are no ICE engines parked in the garage, no gas water heaters, nothing that burns. I open the garage doors and it stops. I close the garage doors and a few minutes later it starts again. No sleep for the weary.
I go to Google. It says that hydrogen can set off certain makes of CO monitors. A light starts to come on. Only in the past few weeks has Mrs Frog started parking her battery powered golf cart in one bay of her garage. Yesterday it was driven a lot, so the charger had a lot of work to do that night. Hydrogen is lighter than air (think Hindenburg). Seems the batteries were bubbling off hydrogen and it was piling up on the ceiling setting off the alarm.
I left the alarm on a bench in the garage and it quit going off. Now I'm thinking of pulling the old one out of the trash to see if it acts the same.
As a side note, the manufacturer states that the alarm is only certified for up to 100 degrees F. On these 115 heat index days It feels like the air on the ceiling of that garage is way over 100. Another thing to consider.
