CO detectors sounding alarm

[Viper]

Qr Bbpost....Thought I saw 3 separate feeds coming off the OEM ACtoDC charger to the three OEM batteries....

Correct, but when you set the selector switch to "BOTH" you are connecting "both" banks together electrically, that's what the switch is designed to do in that position. When you do that, it's like having one big battery, but now the two banks aren't isolated, they are combined. It won't matter where the charger legs are connected, it all becomes part of the same circuit no matter where in the circuit things are hooked up. It would be like hooking up 2 charger outputs to one battery. This confuses some chargers as the two outputs now hooked to the same bank electrically may conflict with one-another. While the two outputs are trying to output a charge of say 14V, each may see 14V already there from the other leg thus think that the battery/bank is charged. Some chargers may be able to deal with this, but some go into a float mode right away or keep cycling on and off, while some chargers shut down completely (all outputs) because of the conflict. The cycling on and off is like trying to start your car on a dead battery. The clicking you hear is the starter solenoid engaging, when it does, the voltage drops even further and causes the solenoid to disengage. When it disengages, the voltage rises again engaging the solenoid again, when it does, the voltage drops again, and so on.....cycling on and off.

[Midnight Sun]

Problem is when you select both, you connect the batteries together as mentioned however you also connect the battery charger leads of independent banks together so you have just defeated the separate charging of banks at the same time.

IMHO, both selection should never be used unless you have a single engine boat and 2 battery banks and want to charge while under way. Then again an ACR does the same thing without fumbling and forgetting switches.

This is my first boat with no combining possible. On/off switch only for each engine, generator, bow thruster, stern thruster, generator and finally house bank. Was rather concerned at first since my last three boats all had multiple selections possible but soon realized the concern was more from habit than anything else. That being said, I prefer things this way as there is no mistake possible which could bring down the entire system such as selecting both/all. I could easily swap a battery physically if one were to short out as there are no less than 5 group 31 units of which only 2 are dedicated start batteries. Then there is the generator that can always charge thing up if required and on top of that I carry one like this https://no.co/gb150 on board for the WTF moments that have never happened yet and serves more to help others than anything else.

[Viper]

Qr Bbpost Problem is when you select both, you connect the batteries together as mentioned however you also connect the battery charger leads of independent banks together so you have just defeated the separate charging of banks at the same time.....

BINGO!!
Give that man a cigar.

Qr Bbpost.... I could easily swap a battery physically if one were to short out....I carry one like this https://no.co/gb150 on board.....

The only thing I would caution here in a gasoline application is that when you hook up ANYTHING to a battery at ANY time, you MUST ensure there are no gas fumes in the bilge in case a spark is generated...so ventilate, ventilate, ventilate. This is why booster cables have always been a bad idea on board. In a panic situation, people often overlook what they'd normally be cautious with. While some booster packs claim not to generate a spark, most do, and personally I would err on the side of caution with the ones making the claim as well. A lot of booster packs now have ON/OFF switches which helps minimize the risk, just make sure they are OFF when hooking up. Having said that, if you don't make a good connection with the clips, you may still generate a spark. For safety, the best way to combine is to have a hard wired combining system in place. A booster pack should only be an absolute last resort when the redundancy of a combining circuit fails....IMO!

[Midnight Sun]

The only thing I would caution here in a gasoline application is that when you hook up ANYTHING to a battery at ANY time, you MUST ensure there are no gas fumes in the bilge in case a spark is generated...so ventilate, ventilate, ventilate. This is why booster cables have always been a bad idea on board. In a panic situation, people often overlook what they'd normally be cautious with. While some booster packs claim not to generate a spark, most do, and personally I would err on the side of caution with the ones making the claim as well. A lot of booster packs now have ON/OFF switches which helps minimize the risk, just make sure they are OFF when hooking up. Having said that, if you don't make a good connection with the clips, you may still generate a spark. For safety, the best way to combine is to have a hard wired combining system in place. A booster pack should only be an absolute last resort when the redundancy of a combining circuit fails....IMO!

I though the most prudent of mariners always open the bilge and smell for fumes before starting? You would need to be in the bilge with hatches open in order to boost anything so fumes should not be an issue IMHO. No cigar for you.

[Viper]

Qr Bbpost .....I though the most prudent of mariners always open the bilge and smell for fumes before starting?

Now THAT'S funny

Qr Bbpost... You would need to be in the bilge with hatches open in order to boost anything so fumes should not be an issue IMHO....

No more cigar for you Under the right conditions, simply having a hatch open isn't enough. Believe me, I've seen first hand what can happen. I have a friend that let his guard down while working on a boat, an experienced mechanic. All I heard was a big bang. He sustained serious injuries but recovered. He got off lucky (I mean really lucky) but the boat was a right off. Hatches open!!

[AaHubb]

Ok sorta related to the OP. Seems odd there isn't a detector for gasoline vapors.
..Aaron

[Midnight Sun]

Qr Bbpost Ok sorta related to the OP. Seems odd there isn't a detector for gasoline vapors.
..Aaron

All my previous gas boats had a gas sniffer connected to the blowers for automatic operation. Tested it every spring to make sure it was operational. Saved my life and my family many years ago but that is another story.

[bud37]

Qr Bbpost Ok sorta related to the OP. Seems odd there isn't a detector for gasoline vapors.
..Aaron

There are detectors for pretty much anything......the sniffer MS is talking about I believe like the Xintex is basically looking for explosive gas of any kind ( explosimeter ), we had one in previous boat ( also tested regularly )....fuel vapours fall into that category and the sensors have to be installed in the correct location for what you are looking for....heavy vapours down low and lighter up higher in the compartment.......

[405driver]

Here is the fix for my CO problem.

I replaced all of the CO detectors, all three batteries and the battery charger. I installed a new Promarine charger and so far it's great. Maybe overkill but all needed to be replaced due to age.

Not sure which one fixed it, but the CO detectors are now silent…..

Thanks for all help.

[Viper]

Thanks for following up and letting us know how you solved the problem. I got your back; I don't think it's overkill. The CO detectors have a limited lifespan, if the batteries where questionable then you made the right move by replacing them so they don't let you down, and it's not wise to spend a large sum of cash on batteries, then charge them with an older charger or one you're not confident is working properly.