Carbon monoxide alarms going off

[OrangeCrush]

Hello,

Living on the mooring these days and just came back to my boat to find two out of two carbon monoxide alarms going off. They are battery powered and separate from each other. There was absolutely nothing on that I can imagine would put off CO, all switches off, nothing burning or running. The boat was buttoned up pretty tight so there might not have been much ventilation, but this shouldn't cause carbon monoxide or even a drop in oxygen levels as far as I know. Everything smells and looks normal. The propane solenoid was off and the propane alarm is still active and not going off. As soon as I opened up some hatches both alarms stopped. What could cause a false alarm or is there a source of CO that I'm not thinking of? Thanks in advance...

[Pizzazz]

Gassing from overcharged lead acid batteries will trigger the alarms.

[a64pilot]

I have heard that batteries charging will do it, possibly the Hydrogen?
However this is rumor mongering if you will, but I have seen it reported more than once
I assume once you aired out the boat now all is well with the alarms ?

[foggysail]

Low alarm batteries, time for new ones

[OrangeCrush]

That is a likely culprit. My solar panels have been keeping my batteries fully charged and the dorade vents were turned backwards so I had almost no ventilation today.

Yes as soon as I opened up the boat the alarms stopped.

Hopefully the batteries aren't overcharging, though, as my solar panels are all on good controllers.

[deblen]

Hydrogen gas can set a CO alarm off.
https://www.safelincs.co.uk/blog/201...arms%E2%80%99/

Len

[Seymore]

Yeah, mine went off for no reason too. I bought one carbon monoxide alarm, installed it and, twice a week, it went off at three o'clock in the morning for no reason. I scrapped it.

[DeepFrz]

Check the fluid level in your batteries.

[OrangeCrush]

Since two of them went off simultaneously yet independently of each other, I'm actually pleased with how well they work (albeit for the wrong gas, hydrogen).

I will check the fluid levels, but is there a reason why the electrolyte being low would cause the batteries to outgas more than normal?

I have a bank of 6 golf cart for a total of 690ah. I run it down about 50ah every night and the solar gets them full by the time I get home. Without much ventilation, it makes sense that the gas would be unable to escape and also in higher concentrations at the ceiling where the detectors are.

[geoleo]

Anything will set the damn things off! I took the batteries out and just have them fake!

[DeepFrz]

Low fluid will give you an indication that they need water. Likely in the event that they have been overcharged and were off gassing.

[Roy M]

Remove the CO alarm unit from the wall, by pulling off the cover, unscrewing the fasteners holding it to the bulkhead, and turn it over. This is for units that operate off a boat power circuit. There will be a small print date and the words REPLACE UNIT AFTER THIS DATE. I just did this for someone last week. They don't last forever.

[OrangeCrush]

Originally Posted by DeepFrz

Low fluid will give you an indication that they need water. Likely in the event that they have been overcharged and were off gassing.

Gotcha, both the hydrogen gas and low fluid would be symptoms of the same problem if they are overcharging.

I have three 100 watt panels, each on a separate Genasun controller. After a day of charging (after the sun has gone down) I find them resting at around 13.1v. I turn on some lights, etc. and they stay at 12.9 for an hour or two before eventually stabilizing at 12.8 where they will stay almost indefinitely. Does this sound right or are these voltages too high for a lead-acid bank?

When I installed my system I thought I was going to need to be careful with my consumption, but after a whole season of usage including running the refrigeration nonstop with minimal battery drain, I've now gone so far as to switch most of my fixtures back to incandescent bulbs. The lowest I got the batteries all summer was 12.5v with a -100ah deficit. Is it possible I have too much solar?

[conachair]

Originally Posted by OrangeCrush

Gotcha, both the hydrogen gas and low fluid would be symptoms of the same problem if they are overcharging.

I have three 100 watt panels, each on a separate Genasun controller. After a day of charging (after the sun has gone down) I find them resting at around 13.1v. I turn on some lights, etc. and they stay at 12.9 for an hour or two before eventually stabilizing at 12.8 where they will stay almost indefinitely. Does this sound right or are these voltages too high for a lead-acid bank?

When I installed my system I thought I was going to need to be careful with my consumption, but after a whole season of usage including running the refrigeration nonstop with minimal battery drain, I've now gone so far as to switch most of my fixtures back to incandescent bulbs. The lowest I got the batteries all summer was 12.5v with a -100ah deficit. Is it possible I have too much solar?

What batteries? Voltages sound fine compared to trojan T105's. This is from living aboard in Portugal..2 x T105 & 300w solar. Complete yesterday with a mini equalise up to low 15v, I find doing that now and again keeps the specific gravity of all the cells equal and high.
Thing to bear in mind, if you're batteries aren't gassing a bit then it's unlikely that they will ever get up to full charge on solar alone, not enough hours in the day. A bit of bubbling doesn't mean over charging, more that the absorption voltage is high enough to get a good charge back in without taking forever. (Obviously sealed are a different ball game..) Just keep an eye on the water, I'll put some in about once a month but nothing major.

My alarm will go off with a 20A mains charger sometimes. Solar won't set it off though that might well be as much with the good breeze coming in from the forepeak as much as anything else.

The graph shows just how useless trying to use voltage as a measure of state of charge is when actually using a boat.

As for too much solar?? Impossible

[thinwater]

Originally Posted by OrangeCrush

... I find them resting at around 13.1v. I turn on some lights, etc. and they stay at 12.9 for an hour or two before eventually stabilizing at 12.8 where they will stay almost indefinitely. Does this sound right or are these voltages too high for a lead-acid bank?...

It depends on temperature and whether there is any load or charging. If it is warm (the battery is warmer than the air due to charging) the voltage could be correct. You may also want to check whether the charger is set for the battery type you have.