Carbon monoxide alarm going off

[daveb]

Sure you're not hearing the 9v battery operated smoke detector?

[DerPo]

Originally Posted by neatvan

DerPo: Are your batteries in the living space as well?

Wow great info neatvan.
My battery is in the living area, to the rear of the passenger side. I've been fiddling with everything lately and the battery was not sealed whie it was charging. Maybe this was the cause? The van is going to be gone for a few weeks so I won't be able to look into properly sealing the battery compartment before charging. But as soon as I get it back ill attempt to recreate it.

[daveb]

There are several chemicals that will set off a CO detector so I'd be looking in that directions as well. I would be a bit concerned about the battery but the percentage to air & lower explosive limit needs to be right for a hydrogen kaboom. Still I have never liked the idea of standard wet cell batteries inside w/o proper venting. I'd feel way safer with AGM (VRLA) batteries mounted inside as they really need to be pushed to vent during normal charging. I don't know how Hydrogen reacts to a carbon monoxide detector but know older CO detectors were not as responsive to CO gas as newer ones are and that they fail over time. I'm not sure if they become more or less sensitive to specific gasses. We have to be schooled in entering large substation battery rooms at work and I do know that hydrogen detectors also go off when exposed to other gasses but generally they're more sensitive to hydrogen than other gasses. Unfortunately the class is on hydrogen rich atmospheres and those type detectors...not CO detectors plus I'm the student, not the instructor.

From the internet concerning battery rooms:
Sulfuric acid is contained in the lead/acid batteries used in the backup power source for the facility. Substations typically have two battery rooms, each containing 30 to 40 car-type batteries. Each battery holds five to 10 gallons of acid with a 30- to 40-percent concentration. Exposure to sulfuric acid under normal conditions presents a dermal hazard, but more significant issues arise when the product is exposed to heat. Sulfuric acid mist can produce serious, if not fatal, injuries to responders who fail to protect against respiratory exposure.
(4) Take note of posted warning signs.
Note that the carbon monoxide (CO) detectors used by the fire service have shown false CO readings in battery rooms. The sensors in these units are cross-sensitive to the hydrogen released when the batteries charge. In one case, personal monitoring devices indicated 50 parts per million (ppm) of carbon monoxide in a substation’s battery room. Additional testing revealed that it was actually hydrogen with a concentration of 1,500 ppm. (The lower explosive limit for hydrogen is 30,000 ppm.)
I wouldn't actually call them "car type batteries" but it's fairly accurate.

Perhaps you can purchase a new CO detector and see if that one goes off as well. I'd still be careful.