A heads up about CO detectors

[Beneteau381]

Got back on the boat last night. The CO detector was pinging occassionaly. Nothing on board being used that could produce CO so I took the batteries out and went to bed. Checked them this morniing and still at 1.49 volts so not that. Then I noticed that there was a sticker on the detector. Basically after 7 years the thing is toast and has to be replaced.
So I took it off the roof and binned it.
This afternoon I came down in to the saloon and smelt a familiar smell similar to 3 years ago! It was toasting battery! The BM1 was showing 14 plus volts and 13 amps charge! Off with the charger and solar controller and in to the battery compartment. The end battery was hot, very hot!
I let it cooll a bit then disconnected it and removed it. It was stinking and v hot.
The moral of the story? If your CO detector goes off and the internal batteries are ok, then a check of the main boat batteries might be in order!

 

[lustyd]

So basically, if an alarm goes off you should listen to it instead of going to sleep? Unfortunately I think a majority would do the same in your situation, humans generally assume things are OK for some reason.

 

[Plum]

Got back on the boat last night. The CO detector was pinging occassionaly. Nothing on board being used that could produce CO so I took the batteries out and went to bed. Checked them this morniing and still at 1.49 volts so not that. Then I noticed that there was a sticker on the detector. Basically after 7 years the thing is toast and has to be replaced.
So I took it off the roof and binned it.
This afternoon I came down in to the saloon and smelt a familiar smell similar to 3 years ago! It was toasting battery! The BM1 was showing 14 plus volts and 13 amps charge! Off with the charger and solar controller and in to the battery compartment. The end battery was hot, very hot!
I let it cooll a bit then disconnected it and removed it. It was stinking and v hot.
The moral of the story? If your CO detector goes off and the internal batteries are ok, then a check of the main boat batteries might be in order!

Yes, CO detectors may also detect a gassing leadacid battery. I had the same before I swapped my old fashioned charger for a smart 4-stage one.

Www.solocoastalsailing.co.uk

 

[VicS]

Don't overlook the fact that it is the electrochemical cell which limits the life of a CO detector . I'd expect the battery to be still OK for longer.

A smart charger may not prevent B 381's experience. If cell shorts and the charger reverts to "bulk charge" the result may well be the same..

 

[PaulRainbow]

Got back on the boat last night. The CO detector was pinging occassionaly. Nothing on board being used that could produce CO so I took the batteries out and went to bed. Checked them this morniing and still at 1.49 volts so not that. Then I noticed that there was a sticker on the detector. Basically after 7 years the thing is toast and has to be replaced.
So I took it off the roof and binned it.
This afternoon I came down in to the saloon and smelt a familiar smell similar to 3 years ago! It was toasting battery! The BM1 was showing 14 plus volts and 13 amps charge! Off with the charger and solar controller and in to the battery compartment. The end battery was hot, very hot!
I let it cooll a bit then disconnected it and removed it. It was stinking and v hot.
The moral of the story? If your CO detector goes off and the internal batteries are ok, then a check of the main boat batteries might be in order!

This was incredibly dangerous !

You should never, ever, disconnect a hot or gassing battery. The smallest spark can ignite the hydrogen and cause an explosion. Let the battery cool, the gas vent and cover with an old towel or something, just in case, as you remove the terminals.

 

[PaulRainbow]

Before someone comes along and tells me batteries do not explode:

 

[Refueler]

This was incredibly dangerous !

You should never, ever, disconnect a hot or gassing battery. The smallest spark can ignite the hydrogen and cause an explosion. Let the battery cool, the gas vent and cover with an old towel or something, just in case, as you remove the terminals.

Or pull the main or supply lead to the charger that is well away from the battery ....

Just a comment ... all chargers I have had - the instructions have always said when connecting to battery - power lead LAST ... when disconnecting from battery - power lead FIRST ... to have battery connectors basically 'dead' to avoid any sparks etc.

 

[Refueler]

I have to add to to Pauls exploded battery .....

I am still not sure why one of my on-board batterys split its case ... maybe the plates were so bad - the charger led it to rupture or it might have been battery had discharged over time and winters -30C froze the now low density electrolyte ...

But the point is - THEY DO explode ... they do fracture.

What really got me though - the trouble and care needed to clean up after. All that acid waiting to eat your gloves / clothes ... anything it can get to .... it took ages for even the aroma to go - even though I'd washed out with alkali base etc. I wish it on no-one ..

 

[Beneteau381]

I

This was incredibly dangerous !

You should never, ever, disconnect a hot or gassing battery. The smallest spark can ignite the hydrogen and cause an explosion. Let the battery cool, the gas vent and cover with an old towel or something, just in case, as you remove the terminals.

I switched everything off including mains and solar charger and main battery switches. I also had ventilated it with a fan prior to starting work.
Stu

 

[Beneteau381]

So basically, if an alarm goes off you should listen to it instead of going to sleep? Unfortunately I think a majority would do the same in your situation, humans generally assume things are OK for some reason.

I knew there wasnt a CO producer working so it wasnt CO, I checked the batteries in the detector at 1.49v so was puzzled. The sticker that was on the bottom said replace detector after 7 yrs and that it would start chirping at or around that date to warn to do so. Assumed that was the cause of the noise. Interesting that it was picking up hydrogen sulphide? before I could smell it as I did the next day afternoon. I am au fait with H2S by the way having worked offshore on a production platform with large quantities of produced H2S gas.

 

[Refueler]

I knew there wasnt a CO producer working so it wasnt CO, I checked the batteries in the detector at 1.49v so was puzzled. The sticker that was on the bottom said replace detector after 7 yrs and that it would start chirping at or around that date to warn to do so. Assumed that was the cause of the noise. Interesting that it was picking up hydrogen sulphide? before I could smell it as I did the next day afternoon. I am au fait with H2S by the way having worked offshore on a production platform with large quantities of produced H2S gas.

You should know that H2S deadens the sense of smell .... that the threshold limit has been passed if you can smell it ...

Its a killer due to that deadening sense of smell ... people get a whiff of it ... then it seems to go away ... people believe its clear ... then 'its all over'.

 

[Forty_Two]

Boats on either side of me have experienced disastrous battery failure. It's more common than we would like i think. Not happened to me yet thank goodness.

Ive been all AGM for the last 16 years.

So far as i can tell failures seem to be lead acid. Has anyone experienced catastrophic failure with AGM batteries?

 

[thinwater]

Cross sensativity with detectors is well known. This is true of propane and CO2 detectors as well (but different gasses and levels). As you can see, H2 is a top offender. For us, this is a good thing.

 

[Beneteau381]

You should know that H2S deadens the sense of smell .... that the threshold limit has been passed if you can smell it ...

Its a killer due to that deadening sense of smell ... people get a whiff of it ... then it seems to go away ... people believe its clear ... then 'its all over'.

I am au fait with H2S by the way having worked offshore on a production platform with large quantities of produced H2S gas.

 

[Beneteau381]

Boats on either side of me have experienced disastrous battery failure. It's more common than we would like i think. Not happened to me yet thank goodness.

Ive been all AGM for the last 16 years.

So far as i can tell failures seem to be lead acid. Has anyone experienced catastrophic failure with AGM batteries?

Isnt AGM lead acid?

 

[Refueler]

I am au fait with H2S by the way having worked offshore on a production platform with large quantities of produced H2S gas.

I was pointing out that if you can smell H2S ... a) you've only just entered the affected area, b) its way over TLV if smelt.

I've been in Petroleum game game for ~50yrs ... actually passed out after suffering H2S + Hydrocarbon poisoning ...

Corner Point Valera Safety Course - actually had to 'quietly' correct the course instructor about TLV etc. of H2S ..... which later he 'quetly' thanked me for highlighting the errors.

 

[Leighb]

LPG detectors are also sensitive to overheating batteries. Just after we had sold our boat, but before hand over, I was walking down the pontoon to get some last minute personal items. As I approached I could hear an alarm and remember thinking “That sounds like a gas alarm” as I got near I realised it was our boat!!
I could smell the H2S in the cockpit, batteries under a hatch in the floor, I went on board, disconnected the shore power, shut off the main battery switches and then lifted the cockpit floor hatch. I then left it for half an hour or so. On return I cautiously opened the battery compartment cover and could see one of the pair of domestic batteries was very hot and bulging slightly. I had to fit a brand new battery for the new owner.
Possibly if I had not sold her I might have replaced both?

 

[Forty_Two]

Isnt AGM lead acid?

Yes they are. I just wondered as they are sealed, the electroyte not free flowing but suspended in the glass matt, if that made a difference in practice to the overall risk of a cell failing.

 

[Beneteau381]

Yes they are. I just wondered as they are sealed, the electroyte not free flowing but suspended in the glass matt, if that made a difference in practice to the overall risk of a cell failing.

I suspect that the problem of toasting batteries is caused by bits dropping off the plates and shorting them out, the bad one was a cheapo bought in haste as a stop gap three years ago. I have been getting sulphation symptoms since last year and again, I suspect my Victron super duper controller with its monthly rqualisation charges, knocked some sulphation off to cause a short in one of the cells. AGM wouldnt suffer from this

 

[Refueler]

I suspect that the problem of toasting batteries is caused by bits dropping off the plates and shorting them out, the bad one was a cheapo bought in haste as a stop gap three years ago. I have been getting sulphation symptoms since last year and again, I suspect my Victron super duper controller with its monthly rqualisation charges, knocked some sulphation off to cause a short in one of the cells. AGM wouldnt suffer from this

I would suspect buckled plate .... not uncommon - especially in leisure batterys called on to deliver high ampage too often.