FLA Batteries outgas & Cabin CO2 Alarm

[jefndeb]

Hello,

After a few hours this past weekend of putting around the local waters yesterday we got back to the dock and got all the lines etc connected back up.

My Mom is staying on the boat by herself and called me later that night saying all 3 of the 3 month old Kiddie CO sensors were beeping and the display was showing number in the 90's.

I asked her to place them outside and they cleared. Placed them back in the boat cabin and they slowly crept up and when the AC was turned back on they climbed higher still.

I told her to come to our house to spend the night and we will investigate the next day.

We have no propane or gas of any type on the boat, nothing that I read that would cause this issue.

The only thing I could think of is that our start battery is a FLA 8D, it was pretty hot and while it was being recharged it outgased and I read that sometimes that can cause the CO sensors to go off.

Anybody else had this happen?

 

[DavidM]

First I think you mean CO detector.

You say it was pretty hot. Does that mean the battery case or the general air temperature? If the former then the battery is bad and needs to be replaced.

If the battery is off gassing that may mean that something is wrong with the charger- too high a voltage and it is disassociating ("boiling") the electrolyte to O2 and H2. That may trigger the CO alarm. Do you use the same charger for the 8D starting battery and your house batteries? That may be why the 8D is off gassing as the parameters are set for the house batteries which provides too high a voltage for the 8D.

All of the above is speculation. I have never had a FLA battery off gas to the point that it was noticeable, or dangerous.

David

 

[jleonard]

My detector used to go off sometimes but only in the spring right after launch when the batteries were down from the winter and being charged a lot.
It would only last a day then never again for the season.

 

[jbabs]

Yes, I had this same issue occur on my previous boat. We had installed a NEST wireless smoke/CO monitoring system on board. Three units - engine room, salon, stateroom. Had a cell go bad in one of the 8D house batteries which started outgassing. The unit in the engine room detected the gas and all three of the units started notifying us in the middle of the night that "CO was detected in the basement"(ie engine room). Checked to see what was going on and while not noticeable in the living areas, the engine room had a bit of that acidic/sulfuric battery smell. So, bottom line is "Yes". An overheated gassing battery can set off your CO detector.

 

[jefndeb]

Our start 8D has its own Xantrex 40A TrueCharge unit, set for FLA.

Our House is 2 8D AGM charged with seperate Victron MultiPlus unit, programmed for an AGM profile

It was a pretty hot day but I didnt go down to feel the battery for its temp.

I read there have been issues with golf carts being charged in peoples house garages that has caused the CO alarms to go off so I was just thinking this might be same situation maybe

 

[firehoser75]

My guess with the limited info available, would be some kind of problem with either the charger or battery, especially if this issue "just started" and nothing has changed.

Maybe the battery now has a bad cell causing overcharging????

 

[Bacchus]

I have seen / heard of batty charging setting off CO alarms.
Check water levels as a bad cell boiling will likely be low.
Check specific gravity of each cell to pinpoint the problem cell.
Is the charger temp compensated?
If not the ER was hot it could have overcharged all cells.

 

[Taras]

Yes. This exact thing happened on my boat. Old battery. Charger kept pumping juice to it, off gassing and that set off the CO alarm.

 

[High Wire]

Yes it will. Check the electrolyte levels and Specific Gravity in ALL battery cells, including generator and thruster batteries if you have them. At least one cell is going bad or the charger voltage is too high.

 

[AusCan]

If they are AGM batteries, there are no levels or liquid to check specific gravity.

Either they have a shorted cell or the battery charger is out of control to produce high levels of CO. Ideally, you should have a temperature sensor on tour battery which will reduce the charging when this happens. Give them a feel. If one is hot, it's likely that is has a shorted cell.

 

[Pmcsurf1]

mine is doing the same thing. Two nights in a row at a marina. Left the ac running and the battery charger on but opened some windows and the alarm went off.
Been reading about it and it is common. Flooded lead acid batteries will off gas hydrogen and some CO detectors will alert on it.
I have a bilge blower on the boat. Its a diesel, so I've never understood the blower but I've installed new duct tubing and we'll see tonight if the alarm goes off.
BTW, seems only to go off when charging my house bank. I've got six Trojan 105 golf cart 6 volt batteries. My charger is a Mastervolt inverter charger combo. I also run three 100 watt solar panels.

 

[High Wire]

See post 9.

 

[FlyWright]

This happened on my boat this year when I overlooked a battery service (or two ) and the electrolyte got too low, frying the 5-yr old batts. Two of my CO detectors went off a week apart as a result.

 

[Pmcsurf1]

See post 9.

Common issue is poor ventilation for charging batteries. Read many storys about home co detectors going off because golf cart batteries charging on garage. Industrial plants with battery back ups must install ventilation systems for the off gassing. Think about how small a space you bilge is compared to 6 or 8 golf cart batteries charging. Way smaller space then a garage.

 

[Pmcsurf1]

Not saying you couldn't have a bad cell but normal charging does off gas hydrogen which sets off many co alarms.