CO alert without combustion?

[CapitalD]

We have Fire Angel CO alarms and one has just started to go off.  We are on our mooring and getting power from our bollard.  We haven't run the engine for a few weeks and have not yet lit our stove this autumn.  We're cooking (by gas) on the boat and on Sunday we made breakfast and went out for the day (by car).  When we cam back on Monday morning the alarm was going reading 38ppm over our bed.  Since then the recorded level has been going up and down from the usual 0 to as much as 41 ppm.  There is no gas coming into the boat unless the cooker is on (bubble tester).  There is a smell similar to rotten eggs (hydrogen sulphide) strongest near the stern bed area.  The forward (kitchen/living space) monitor is reading 0 to 13 ppm.    I can't locate the source of the smell which is obvious but not powerful.

 

Does anyone have any idea where to look next?  Are the monitors sensitive to anything other then CO?

[Guest]

Gassing batteries.

[Alan de Enfield]

VERY QUICKLY have a look at your batteries - I had this in the middle of the night, the batteries were minutes from exploding.

Feel if the batteries are warm (mine was so hot I could not touch it) disconnect all wiring to any hot batteries, let them cool down and gently lift them off the boat.

 

They may well be a peculiar shape with the ends bowed outwards and under a lot of strain.

 

Do you regularly check the water levels in the battery ?- usage of water is one of the 1st stages of a poorly battery'

Edited October 21, 2020 by Alan de Enfield

[TheBiscuits]

Batteries overcharging.

 

@Alan de Enfield will be along shortly ...

 

Add: ... Nope, he was ahead of me!

[GUMPY]

Yes overcharging batteries.

Suggest you check the temperature of your batteries individually by hand, if one is warmer than the rest disconnect it.

To slow again but we all agree

 

[Jen-in-Wellies]

CO monitors will also register Hydrogen. Badly gassing batteries will produce Hydrogen and Hydrogen Sulphide (rotten egg smell) from the Sulphuric acid electrolyte inside.

Jen

Edited October 21, 2020 by Jen-in-Wellies

[Mad Harold]

8 minutes ago, Loddon said:

Yes overcharging batteries.

Suggest you check the temperature of your batteries individually by hand, if one is warmer than the rest disconnect it.

To slow again but we all agree

 

My CO detector went off due to overcharged battery.

I have a small (10W) solar panel and no solar controller at the time.Only 10W,but it still overcharged the battery.

Now have a cheapie Chinese solar controller fitted,and no further CO warning.

[CapitalD]

Thanks guys.  One (of 4) running warm to touch, now disconnected.  They were due to be changed this year when cruising season is over ...