CO alarm in the night - Unsure of cause

[Tony Brooks]

15 minutes ago, DShK said:

Update to this - batteries continue to gas when charging from a moderate discharge state. I just fitted 1500W of new solar panels and these are now causing the alarm to go off.

 

I began to wonder if the previous owner had set the voltage wrong - so reached out to the battery supplier for info.  They are monbat GC2B 6v cells. I can't quite make heads or tails of the datasheet they gave me though - the graph given for voltages doesn't match my understanding for a IUI charge profile. It looks like 12v raising to 14.4V for bulk/absorption. But then it raises even further to 15.9? I don't understand why this graph doesn't drop to a float voltage. 15.9 Seems extremely high. The charger is currently set to 14.8V which is higher than that 14.4V value - perhaps this is causing the gasing? Or do my batteries just need replacing?

 

As a perhaps point of note - it seems to me that the alarm is always getting set off when the smartguage has hit 100% - not sure if just latency, but I did turn on the charger when the batteries were already at 100 (I think I accidentally turned the charger off, unless the switch on it is also somehow a breaker?) and the batteries began to gurgle quite loudly.

 

My comment would be that the "Final Charging" section is what we mostly call equalization that should not be an everyday occurrence, maybe once a week at the most and under manual control.

 

The 14.4 volts makes me think the batteries are lead antinomy rather than leat calcium that start to gas at a higher voltage but as long as you can keep lead acids topped up can tolerate more equalization.

 

I think you definitely need to check the charging voltage set on the Solar controller and any battery charger. Do you have a decent digital voltmeter to monitor the battery/charging voltage. You need to find the actual voltage when the cells are gassing.

 

Have you at any time had the panels connected to the solar controller, but the battery isolated from it. If so it may be very confused. Disconnect the panels, disconnect the batteries, let stand for half an hour, then reconnect the batteries first and panels second.

[DShK]

Yeah I guess that would make sense about equalisation. But then it makes no note of what float should be set to.

 

The charger is set to (by the previous owner) 14.8V, so I set the solar controller to be the same. Is this voltage difference enough to cause the gassing? 

 

So I should measure the voltage across the batteries when they hit their peak voltage (reads as 14.8V on shunt/solar controller)?

 

No, I was aware that having the panels connected to the controller without it being connected to the battery could fry the controller. I connected the controller to the batteries first, then wired in the panels. I have a breaker to isolate the panels between the controller and the panels (which I'm using now to stop the gassing!).

 

In any case I don't think there is anything going wrong with the solar - it's doing the same as I would get with a shoreline. I just think the old panels/controller were not powerful enough to keep up with power consumption to get to this point (400w vs 1500w).

Edited July 29, 2022 by DShK

[Tony Brooks]

26 minutes ago, DShK said:

Yeah I guess that would make sense about equalisation. But then it makes no note of what float should be set to.

 

The charger is set to (by the previous owner) 14.8V, so I set the solar controller to be the same. Is this voltage difference enough to cause the gassing? 

 

So I should measure the voltage across the batteries when they hit their peak voltage (reads as 14.8V on shunt/solar controller)?

 

No, I was aware that having the panels connected to the controller without it being connected to the battery could fry the controller. I connected the controller to the batteries first, then wired in the panels. I have a breaker to isolate the panels between the controller and the panels (which I'm using now to stop the gassing!).

 

In any case I don't think there is anything going wrong with the solar - it's doing the same as I would get with a shoreline. I just think the old panels/controller were not powerful enough to keep up with power consumption to get to this point (400w vs 1500w).

 

14.8V float or absorption will definitely cause lead antinomy batteries to gas and will probably cause lead calcium ones to do the same. It is 0.4V above the typical  LAn gassing voltage and 0.1V above the LC gassing voltage.

 

I would set the normal absorption) voltage to 14.4 if LAn or 14.6 is LC. Typically the float voltage will be about 13.6 volts or so, I would set to 13.7V.

 

Yes, measure the voltage when it reaches the maximum. I think that you have just found out why they are gassing.  It looks to me as if it is just mis-setting the charger and controller.

[DShK]

12 minutes ago, Tony Brooks said:

 

14.8V float or absorption will definitely cause lead antinomy batteries to gas and will probably cause lead calcium ones to do the same. It is 0.4V above the typical  LAn gassing voltage and 0.1V above the LC gassing voltage.

 

I would set the normal absorption) voltage to 14.4 if LAn or 14.6 is LC. Typically the float voltage will be about 13.6 volts or so, I would set to 13.7V.

 

Yes, measure the voltage when it reaches the maximum. I think that you have just found out why they are gassing.  It looks to me as if it is just mis-setting the charger and controller.

 

Okay great, this sound really hopeful then! Now I worry what other stuff the previous owner (who did the fit out) might have done wrong elsewhere 🙃 

 

I checked the spec sheet and they are Antimony, so I will set the absorption/bulk to 14.4V and the float to 13.7V. Fingers crossed this solves the issue! Thanks so much for the help, hopefully this is the end of this saga!

[DShK]

My problem is hardwired into my alternator regulator 🙄 These don't look to be sold anymore - looks like you can get them cheap enough on ebay but no mentions of voltage unlike my one. What's my best bet for alternator regulation?

 

Oh and I'll just pop this in here so I don't make another thread for it - I have a smart bank for split charging, and the relay it connects to makes a constant loud squeeeeeeeeeeeeeee noise when it's connected - is it supposed to do this? Is there an option that won't drive me as mad??

[AndrewIC]

9 minutes ago, DShK said:

My problem is hardwired into my alternator regulator 🙄 These don't look to be sold anymore - looks like you can get them cheap enough on ebay but no mentions of voltage unlike my one. What's my best bet for alternator regulation?

 

Oh and I'll just pop this in here so I don't make another thread for it - I have a smart bank for split charging, and the relay it connects to makes a constant loud squeeeeeeeeeeeeeee noise when it's connected - is it supposed to do this? Is there an option that won't drive me as mad??

Standard Adverc cycle is 14.0-14.4V, temperature compensated. They are still available: https://adverc.co.uk/collections/adverc-battery-systems/products/adverc-battery-systems. Give them a call and see if they will tell you how to adjust yours back to the standard settings?

See also here: 

 

Edited July 30, 2022 by AndrewIC

[DShK]

4 minutes ago, AndrewIC said:

Standard Adverc cycle is 14.0-14.4V, temperature compensated. They are still available: https://adverc.co.uk/collections/adverc-battery-systems/products/adverc-battery-systems. Give them a call and see if they will tell you how to adjust yours back to the standard settings?

 

Ah okay! Yeah that's worth a go, I'll get in contact with them and see if it's possible for me to modify it.

 

I really feel like I'm missing something - clearly some effort has been put in to charge these batteries at 14.8V. I wonder why? The batteries are about 4 years old, but the boat is 12. Perhaps they replaced the batteries with something different and didn't think to update this stuff. After all they told me they "did gas sometimes, but we just increased ventilation" (which I read as opening the hatches). 

[ditchcrawler]

3 hours ago, DShK said:

 

Ah okay! Yeah that's worth a go, I'll get in contact with them and see if it's possible for me to modify it.

 

I really feel like I'm missing something - clearly some effort has been put in to charge these batteries at 14.8V. I wonder why? The batteries are about 4 years old, but the boat is 12. Perhaps they replaced the batteries with something different and didn't think to update this stuff. After all they told me they "did gas sometimes, but we just increased ventilation" (which I read as opening the hatches). 

There is a pot inside them to adjust the voltage, I think @dmr can tell you exactly where, I modified mine externally. In the meantime just pull the plug out of the bottom of it and disable it

Edited July 30, 2022 by ditchcrawler

[DShK]

48 minutes ago, ditchcrawler said:

There is a pot inside them to adjust the voltage, I think @dmr can tell you exactly where, I modified mine externally. In the meantime just pull the plug out of the bottom of it and disable it

I had a little search now you've mentioned this, and I found a thread where, who I believe to be the original owner of the boat was asking how to adjust it! Also mentions you can send them back to Adverc to adjust if required. Seems it can be a little bit tricky to do, as you have to watch the voltage and only adjust it when it's hit a certain part of it's cycle. Thanks for the info. I assume pulling the plug out just means the alternator won't fully charge my batteries - no real problem at the moment.

[dmr]

3 hours ago, DShK said:

I had a little search now you've mentioned this, and I found a thread where, who I believe to be the original owner of the boat was asking how to adjust it! Also mentions you can send them back to Adverc to adjust if required. Seems it can be a little bit tricky to do, as you have to watch the voltage and only adjust it when it's hit a certain part of it's cycle. Thanks for the info. I assume pulling the plug out just means the alternator won't fully charge my batteries - no real problem at the moment.

 

Its not difficult, you will need to watch the voltage till it changes, then you know whether it is in the high or low part of the cycle, then turn a preset to set the voltage.  You will need something to measure voltage at the batteries if you don't already have that.

The Adverc does go into a long rest period which is tedious, but otherwise watching the voltage for about 20 mins shoud be enough.

 

Do note that the Adverc can only increase the voltage so best to set the voltage in the high part of the cycle, if the alternator regulator is higher than the Adverc low voltage then you won't measure the correct low cycle voltage. Easy to unplug the Adverc to understand what is going on.

 

The Adverc is now a bit dated but still good.

[DShK]

1 hour ago, dmr said:

 

Its not difficult, you will need to watch the voltage till it changes, then you know whether it is in the high or low part of the cycle, then turn a preset to set the voltage.  You will need something to measure voltage at the batteries if you don't already have that.

The Adverc does go into a long rest period which is tedious, but otherwise watching the voltage for about 20 mins shoud be enough.

 

Do note that the Adverc can only increase the voltage so best to set the voltage in the high part of the cycle, if the alternator regulator is higher than the Adverc low voltage then you won't measure the correct low cycle voltage. Easy to unplug the Adverc to understand what is going on.

 

The Adverc is now a bit dated but still good.

 

That's great info thank you! I will give it a go - is the pot to change the voltage easy to get to?

[dmr]

10 minutes ago, DShK said:

 

That's great info thank you! I will give it a go - is the pot to change the voltage easy to get to?

 

take the Adverc of whatever its screwed to, unscrew 4 screws at the back to open the box, just one preset pot towards a corner of the PCB. I have some photos somewhere but might struggle to find them 😀

[DShK]

34 minutes ago, dmr said:

 

take the Adverc of whatever its screwed to, unscrew 4 screws at the back to open the box, just one preset pot towards a corner of the PCB. I have some photos somewhere but might struggle to find them 😀

 

I should be able to figure it out from that! Thank you! I ordered some crocodile clip leads for my multimeter so when those arrive I'll give it a go.

[DShK]

Update: Adverc were very helpful, they sent me a document with images on how to do it, or they could do it for me while servicing the unit for £30+PP. I appreciate that they gave both options, great customer service (given technically I am not even a customer!).

 

My CO alarm has not been set off by either my charger or my solar since changing the voltages, so I think this problem has been solved. Thanks to everyone who posted suggestions and help!

[ditchcrawler]

1 hour ago, DShK said:

Update: Adverc were very helpful, they sent me a document with images on how to do it, or they could do it for me while servicing the unit for £30+PP. I appreciate that they gave both options, great customer service (given technically I am not even a customer!).

 

My CO alarm has not been set off by either my charger or my solar since changing the voltages, so I think this problem has been solved. Thanks to everyone who posted suggestions and help!

 

1 hour ago, DShK said:

Update: Adverc were very helpful, they sent me a document with images on how to do it, or they could do it for me while servicing the unit for £30+PP. I appreciate that they gave both options, great customer service (given technically I am not even a customer!).

 

My CO alarm has not been set off by either my charger or my solar since changing the voltages, so I think this problem has been solved. Thanks to everyone who posted suggestions and help!

When I bought my Adverc I had a long chat with them on the phone as my alternator was self exciting with no warning light. very helpful 

[DShK]

I've been out and about a lot so haven't been using my charger - back in the marina now and it is still gassing 😔 I don't think the solar is causing gassing, certainly I haven't experienced the CO going off - but there are a lot of variables at play that may effect that. Am I missing anything in my charger settings? They look fine to me but perhaps I am missing something.

 

Edit: Are values like min bulk time wrong? This is the starting bulk voltage. Given the graph on the previous page, should this be 12V? Although how does that work if the batteries are already above 12V?

 

As a point of note, in my victron app for the panels, it lists the highest battery voltage and it is above 14.4V on some days - although I am not sure how accurate this is as it lists the max PV watts which doesn't match it's own graph.

 

My worry is that as winter comes, I will be using the charger a lot more to push my batteries to 100% and making them gas every single day.

 

 

Edited August 19, 2022 by DShK

[cuthound]

3 hours ago, DShK said:

I've been out and about a lot so haven't been using my charger - back in the marina now and it is still gassing 😔 I don't think the solar is causing gassing, certainly I haven't experienced the CO going off - but there are a lot of variables at play that may effect that. Am I missing anything in my charger settings? They look fine to me but perhaps I am missing something.

 

Edit: Are values like min bulk time wrong? This is the starting bulk voltage. Given the graph on the previous page, should this be 12V? Although how does that work if the batteries are already above 12V?

 

As a point of note, in my victron app for the panels, it lists the highest battery voltage and it is above 14.4V on some days - although I am not sure how accurate this is as it lists the max PV watts which doesn't match it's own graph.

 

My worry is that as winter comes, I will be using the charger a lot more to push my batteries to 100% and making them gas every single day.

 

 

 

With lead acid batteries the 12 volt refence is nominal voltage.

 

The actual voltage will range from about 10.5 (completely flat) to 16.0 (the highest voltage you will see at the end of an equalising charge).

 

The chart below shows approximate state of charge for 12 volt lead acid batteries when they are off load and have been for a few hours after being charged.

 

Your bulk charge voltage and time are fine. The battery will continue to charge during the absorption phase and the float phase will hold the battery at a steady state of charge.

 

 

 

 

Edited August 19, 2022 by cuthound
Clarification

[DShK]

2 hours ago, cuthound said:

 

With lead acid batteries the 12 volt refence is nominal voltage.

 

The actual voltage will range from about 10.5 (completely flat) to 16.0 (the highest voltage you will see at the end of an equalising charge).

 

The chart below shows approximate state of charge for 12 volt lead acid batteries when they are off load and have been for a few hours after being charged.

 

Your bulk charge voltage and time are fine. The battery will continue to charge during the absorption phase and the float phase will hold the battery at a steady state of charge.

 

 

 

 

I understand that yeah, I have a decent grasp on battery charging. I'm just trying to understand if the max bulk time is important, and if so what it should be set to.

 

Saying that, I guess when it goes on charge it's going to quickly be above this voltage, so will set the timer off (I misread what this value does, it's the voltage to start the max bulk time timer rather than the voltage to start charging at).

 

My next troubleshooting steps:

 

I'm going to leave my engine room unventilated for a few days when it's sunny and just confirm that the solar getting the batteries to 100% and keeping them there doesn't set the Alarm off.

 

I will get the batteries to discharge more deeply and see if the solar alone causes gassing charging from 50% or so.

 

I will plug in the charger when the solar already has the batteries on float and see if that causes gassing.

 

Hopefully this will help confirm if it's the charger alone causing the gassing, or if it's charging the batteries from a deeply discharged state causing it. Should eliminate a few variables.

Edited August 19, 2022 by DShK

[cuthound]

2 hours ago, DShK said:

I understand that yeah, I have a decent grasp on battery charging. I'm just trying to understand if the max bulk time is important, and if so what it should be set to.

 

Saying that, I guess when it goes on charge it's going to quickly be above this voltage, so will set the timer off (I misread what this value does, it's the voltage to start the max bulk time timer rather than the voltage to start charging at).

 

My next troubleshooting steps:

 

I'm going to leave my engine room unventilated for a few days when it's sunny and just confirm that the solar getting the batteries to 100% and keeping them there doesn't set the Alarm off.

 

I will get the batteries to discharge more deeply and see if the solar alone causes gassing charging from 50% or so.

 

I will plug in the charger when the solar already has the batteries on float and see if that causes gassing.

 

Hopefully this will help confirm if it's the charger alone causing the gassing, or if it's charging the batteries from a deeply discharged state causing it. Should eliminate a few variables.

 

Gassing begins when when almost all almost all of the lead sulphate which hasn't become permanently hard through undercharging has been converted back to lead and lead dioxide. This happens at little over 14 volts, i.e. towards the end of charging.

 

If this happens soon after charging commences it is a sure indication that your batteries are goosed through persistent undercharging.

[Tony Brooks]

12 hours ago, cuthound said:

 

Gassing begins when when almost all almost all of the lead sulphate which hasn't become permanently hard through undercharging has been converted back to lead and lead dioxide. This happens at little over 14 volts, i.e. towards the end of charging.

 

If this happens soon after charging commences it is a sure indication that your batteries are goosed through persistent undercharging.

 

I agree that gassing to a level liable to trigger a CO alarm is more likely to indicate battery problems but suspect it is more likely to be a shorting cell or cells rather than sulphation. I would put shorting cells down to either just plain old age or excess cycling rather than persistent under charging.

 

I have experienced solar hiding the early stages of a shorting start battery so presume similar could happen to the domestic bank,  specially if the hours of darkness electrical loads are few.

 

I will repeat this for the benefit of those new to battery topics, but boaters do need to monitor the state of charge of their batteries early morning and soon after engine shutdown/stopping charging over a period of time so they can spot variations they can not explain by use. Using rested voltage is near enough for this.

 

Sulphation is the same as loss of capacity so you get a fast charge but also a fast discharge. Any gassing will be H & O with minimal smell and little or no acid splatter around the vents. The ends of the battery case may well have bowed outwards because the sulphate takes up more space than the oxide of lead. The state of charge derived from rested voltage and from a hydrometer will differ, the greater the difference the more sulphation.

 

Shorting cells will give a slow charge and a fast discharger. Any gassing is likely to be excessive on individual shorting cells and is likely to smell of rotten eggs. Individual cells are likely to be dry and may be locally hot when under charge.

[Tracy D'arth]

As far as my knowledge extends, only hydrogen and oxygen are released when a charging lead acid sell is gassing. Hence it loses water.

Neither of these will actuate a carbon monoxide detector.

What will cause activation is hydrogen sulphide, the bad eggs smell, which is poisonous. This is released when a damaged ( shorting ) cell is charged and becomes overheated.

 

If your CO alarm is being activated by H2S, you have a failed battery, period.

[AndrewIC]

24 minutes ago, Tracy D'arth said:

As far as my knowledge extends, only hydrogen and oxygen are released when a charging lead acid sell is gassing. Hence it loses water.

Neither of these will actuate a carbon monoxide detector.

A quick Google turns up a number of sources which disagree with you, and assert the CO detectors can have cross-sensitivity for hydrogen. Some of them are even reputable

 

But you are right about the H2S, and detectors can be cross-sensitive to that as well.

[Tony Brooks]

8 minutes ago, AndrewIC said:

A quick Google turns up a number of sources which disagree with you, and assert the CO detectors can have cross-sensitivity for hydrogen. Some of them are even reputable

 

But you are right about the H2S, and detectors can be cross-sensitive to that as well.

 

The only thing that makes me less inclined to blame hydrogen is that it should be up under the roof and not where  they advise you fit CO  alarms. No idea about the density of H2S though.

[AndrewIC]

1 minute ago, Tony Brooks said:

 

The only thing that makes me less inclined to blame hydrogen is that it should be up under the roof and not where  they advise you fit CO  alarms. No idea about the density of H2S though.

Yeah, H2 doesn’t hang about.

[Chewbacka]

1 hour ago, Tracy D'arth said:

As far as my knowledge extends, only hydrogen and oxygen are released when a charging lead acid sell is gassing. Hence it loses water.

Neither of these will actuate a carbon monoxide detector.

What will cause activation is hydrogen sulphide, the bad eggs smell, which is poisonous. This is released when a damaged ( shorting ) cell is charged and becomes overheated.

 

If your CO alarm is being activated by H2S, you have a failed battery, period.

Just for interest I copied this from the Honeywell web site regarding CO alarms - “The electrochemical CO sensors used in the majority of our products do have a cross-sensitivity to elemental hydrogen (H2) gas, with the precise degree of cross-sensitivity depending on the model in question.”