Leaky Squirrel!

[ditchcrawler]

5 hours ago, blackrose said:

 

  only an idiot would block all their vents while running a stove. The OP certainly doesn't sound like the type.

People have died doing it and I feel the BSS is partly to blame with there requirement, lots of boats feel as they have a gale blowing through them at times. 

[MtB]

8 hours ago, blackrose said:

only an idiot would block all their vents while running a stove

 

Not true. 

 

"Only an idiot who knows why the vents are there, would block them up while running a stove" might be more accurate.

 

As a gas technician I routinely encounter perfectly intelligent and resourceful people who have blocked up their air vents, fitted to supply combustion air to their open flue gas boilers. Blocked up to get rid of the draught, not being aware of their true purpose. 

 

Not unreasonably, people tend to think the air vents are there simply to provide ventilation to interior of the boat or the house, and it is within their gift as owner of the place to decide there is too much and close them off. 

 

 

 

 

Edited March 10 by MtB
Add the last para.

[LadyG]

I have to say that carbon monoxide is a deadly and insidious gas.

My boat has plenty of ventilation, the standard vents in doors, mushroom vents, and in addition I have the rear sliding hatch cracked open, there is also a side window which is cracked open.

However the other day when the stove was struggling to ignite new coals, it was a windless day. I cracked the door open,  and I also had opened it a few times to empty ashes etc, both alarms went off, i had to put them outside to stop them, and open all doors and windows to change the air.

I think that carbon monoxide is most likely when the coals are glowing red rather than when the fire is being lit with kindling etc.

[Richardcn]

Hi again all.

 

For some reason I stopped getting notifications on this thread so I apologise for not replying at all. There has been some progress however!

 

Whilst I was unable to properly access the rear plate to check for leaks due to the temperature of the stove (and the desire not to make the manageable situation any worse while the stove was still a critical system) I thought I'd double check something, just to rule it out 100% and I think I've discovered the culprit.

 

Although I still have to prove my theory (without any doubt) by deliberately recreating the problem it appears that it was a false positive caused by hydrogen from the batteries gassing. I really don't know how the gas is making it all the way up the boat from the engine room, avoiding tripping the CO detector in the back cabin (which is open to the engine room), avoiding tripping the CO detector in the bedroom (behind a closed door with brush seals but on the other side of the room) but since I've dialled down the solar charging voltage to 14.4v from my Winter setting of 15v we have had absolutely ZERO CO readings!

 

I did wonder much earlier if this was the cause, given the timing of the positive readings but I had discounted it by opening up the back end of the boat (sliding hatch & side hatch) when we had a reading of 20ish one day. The reading didn't go away as quickly I as I thought it should have but maybe I was a bit too hasty to discount it as a possibility. It certainly seems that way now, anyway.

 

It might be a week or two before I get to do the final test as we're out for blacking very soon but I will post back the result.

 

Thanks again for your suggestions in the interim.

 

Regards

Richard

 

PS. I should just add that our FLA batteries are pretty old now and also they are due to be topped up so, in addition to the high charging voltage, the gassing may well be much higher than the norm.

Edited March 15 by Richardcn
Added info

[ditchcrawler]

1 hour ago, Richardcn said:

 

 

PS. I should just add that our FLA batteries are pretty old now and also they are due to be topped up so, in addition to the high charging voltage, the gassing may well be much higher than the norm.

Are you on a shore supply?

[Tracy D'arth]

You have been very lucky to survive. It ain't hydrogen mate but toxic hydrogen sulphide gas which is a cumulative poison. Even low level exposure can do you serious damage.

[matty40s]

On 10/03/2024 at 04:18, blackrose said:

 

Is any canal boat cabin really sealed up tight? I know the bss rules on ventilation are now advisory rather than mandatory, but all the canal boats I've ever seen still have fixed non-closeable ventilation and only an idiot would block all their vents while running a stove. 

You would be amazed at how many boats we get in which have cardboard panels behind their vents, or even kingspan blocks. 

There is one local boat who seals all his hatches, mushrooms and doors with gaffer tape, it's a pig to do work on his boat as when he comes home he re-instates all the stuff and we have to remove it again next day!!

[Richardcn]

2 hours ago, ditchcrawler said:

Are you on a shore supply?

No

2 hours ago, Tracy D'arth said:

You have been very lucky to survive. It ain't hydrogen mate but toxic hydrogen sulphide gas which is a cumulative poison. Even low level exposure can do you serious damage.

Well that sounds highly unpleasant and I won't downplay something that I have little knowledge of but I don't know quite how much it takes to show a false reading on a CO monitor. We certainly haven't been getting any unusual symptoms so I'd hope that we've not suffered any harm. I'll certainly do some research though. I can't imagine that we're the only boat to ever suffer from this, IF this turns out to be the cause of our readings. We'll have to wait and see.

 

Thanks for the heads up though.

I will just add that the boat is in its original layout of many years, batteries are below the floor (with vent holes) in the engine room. There are lots of air gaps down that end of the boat and a fairly well 'sealed' door between that and the rest of the cabin space. It's always closed during the cold months and open (apart from overnight) during the warmer months as Harvey the cat loves sleeping down there when it's warmer. We've changed nothing between the batteries and us, just refurbished the fireplace. I can't really work out what has changed to create the situation but we are fairly risk averse so we will keep plugging away until we resolve the situation. We continually check our CO monitors and immediately ventilate whenever necessary which, apart from this new issue, is not that often. Having said about a year ago we realised that our grill needed servicing as it was also giving us CO readings but this is unrelated as we rarely use the grill in the day and it's been fixed anyhow.

 

Richard

[ditchcrawler]

55 minutes ago, Richardcn said:

No

 

I was wondering where your high voltage was coming from and thought maybe shore supply 

[Richardcn]

4 minutes ago, ditchcrawler said:

I was wondering where your high voltage was coming from and thought maybe shore supply 

No, it's from solar which (charge voltage) I adjust to suit the season. I've probably been a bit slow to dial it down this year but we have been moored in very open locations and we are overspec'd to keep us charged for as many months as possible, it saves running the dreaded genny (currently kaput!).

[Tracy D'arth]

13 hours ago, Richardcn said:

No, it's from solar which (charge voltage) I adjust to suit the season. I've probably been a bit slow to dial it down this year but we have been moored in very open locations and we are overspec'd to keep us charged for as many months as possible, it saves running the dreaded genny (currently kaput!).

But sealed lead acid batteries should be charged at 14.4 volts, open cells at 14.8 volts  Maximum!

Charging at 15 volts will boil the cells, create hydrogen sulphide and result in water loss and destroyed batteries.

[Alan de Enfield]

12 minutes ago, Tracy D'arth said:

But sealed lead acid batteries should be charged at 14.4 volts, open cells at 14.8 volts  Maximum!

Charging at 15 volts will boil the cells, create hydrogen sulphide and result in water loss and destroyed batteries.

 

Beat me to it - I was going to suggest that he is a closet 'bunny boiler'.

 

Even on 'open' FLAs the 15+V charge mut be at very VERY small current levels and not maintained for hours.

On my 1200AH battery bank I keep the 15+V charging to around 1 amp and only for a couple of hours.

(I have a power supply with which I can exactly control both the voltage and the supply current)

[Richardcn]

I don't think I said that they were sealed, did I? The only 'sealed' I mentioned was the door. I just said FLA IIRC.

Manufacturer recommends 14.1v - 15v charging (at 25C) held for 2-3 hours at the end and that doesn't even take into account any adjustment for the temperature, with ours generally sitting at about 10C or somewhat lower in mid Winter! As I mentioned, this is the Solar charge setting and as we all know there is precious little of that to be had in Winter. Hence that 15v is not often reached and if it is it's not for very long. To add to that the Manufacturer recommends that "if cycled daily, an equalisation charge of 15.6v should be applied every 2 weeks" (yes 2 weekly). I'm happy that I'm well within charging guidelines for our batteries thanks.

[Tracy D'arth]

4 hours ago, Richardcn said:

I don't think I said that they were sealed, did I? The only 'sealed' I mentioned was the door. I just said FLA IIRC.

Manufacturer recommends 14.1v - 15v charging (at 25C) held for 2-3 hours at the end and that doesn't even take into account any adjustment for the temperature, with ours generally sitting at about 10C or somewhat lower in mid Winter! As I mentioned, this is the Solar charge setting and as we all know there is precious little of that to be had in Winter. Hence that 15v is not often reached and if it is it's not for very long. To add to that the Manufacturer recommends that "if cycled daily, an equalisation charge of 15.6v should be applied every 2 weeks" (yes 2 weekly). I'm happy that I'm well within charging guidelines for our batteries thanks.

As the batteries produced H2S which is not normal, the charging regime is obviously wrong, end of.

[LadyG]

I've had all my batteries replaced or removed in the four years of cc off grid.

We did find another battery gassing H2S, which was still connected even after all the batteries were supposed to have been replaced.

Obviously it has now been removed. It was hidden well up in the bow, and required considerable effort to remove it, it was huge, probably twenty years old!

I am not a person who gets headaches, so if I ever feel one coming on i open all doors and windows to make sure the air is changed.

Edited March 17 by LadyG

[MtB]

13 hours ago, Tracy D'arth said:

As the batteries produced H2S which is not normal, the charging regime is obviously wrong, end of.

 

Curious now. I thought batteries gassing during charging produced H2. 

 

Are you saying the gas is actually H2S always, whenever the little bubbles are forming during normal charging?

 

Or is it only H2S during 'abnormal' charging? If the latter when dos it change over to H2S? 

 

I am also under the impression a CO detector will detect and sound if both H2 and H2S in enough concentration get into the sensor. 

 

Thanks.

[Richardcn]

1 hour ago, LadyG said:

We did find another battery gassing H2S...

How did you discover this?

14 hours ago, Tracy D'arth said:

As the batteries produced H2S which is not normal, the charging regime is obviously wrong, end of.

We have no way of knowing that the batteries were producing H2S, that is purely an assumption on your part. Indeed, from what I understand having done some research, H2S will tend to have the smell of rotten eggs which we have not had at all. Also, H2S is heavier than air (apparently) and thus would stay in the battery box/floor level and thus highly unlikely to reach our CO monitor. It is completely normal for 'open' lead acid batteries to produce some Hydrogen when charging (which is lighter than air) and that is sufficient to cause a reading on a CO monitor. Older batteries may produce significantly more Hydrogen, which I already knew (but had forgotten). 

 

I did already admit that I may have been a bit slow to come out of our Winter regime and maybe the batteries are 'older' (in terms of usage) than I realised so this may have been the cause of our CO readings.

 

It would have been nice to see an admission that you mistakenly identified our batteries as 'sealed' which seemed to be the point at which further assumptions were made (or escalated). Whilst I appreciate all advice given (always have and always will) I do wish people wouldn't see the need to blow things out of proportion based on assumptions.

 

Anyway, no hard feelings, life's too short and all that jazz.

 

Regards

Richard

[Tracy D'arth]

I did not assume the batteries were sealed, I gave both voltages for correct charging.

H2S will smell of bad eggs but it is an insidious gas as exposure to very low levels will cause the sense of smell over time to lessen so that eventually you cannot smell it.

 

Worry not, its the last time I will respond to any post of yours if you want to get so snotty when I give you the benefit of my experience and advice for free.

[Richardcn]

10 minutes ago, Tracy D'arth said:

I did not assume the batteries were sealed, I gave both voltages for correct charging.

H2S will smell of bad eggs but it is an insidious gas as exposure to very low levels will cause the sense of smell over time to lessen so that eventually you cannot smell it.

 

Worry not, its the last time I will respond to any post of yours if you want to get so snotty when I give you the benefit of my experience and advice for free.

No not at all. Feel free to post. Apologies if I misinterpreted or misunderstood you.

 

Regards

Richard

[Richardcn]

A brief update for anybody that still interested.

 

I topped up the batteries today and found that they were all at about minimum levels. Our early evening post-solar voltages always indicate to me the need for a top-up if we've not reached out scheduled check before that. However, one cell of 3 (they're 6v batteries), was below minimum with plates exposed. I do check routinely, moreso in the summer, so this appears to be a problem with that particular cell. It's very possible (likely) that this has led to extra gassing which was affecting our CO monitor. I'm still not sure how it's finding it's way into the front cabin when there are some many easier routes of ventilation in the engine room but I have to accept that it may well be doing so. Only time will tell if the low fluid is a sign of the beginning of the end for pair of batteries or if the low fluid itself has caused harm. I'll have to keep a closer eye on it but, for now anyway, the batteries are still performing the same as before. Yes, harder charging means more water but I'm used to that and usually well on top of it. This time, maybe because one cell is failing, I've been caught out but you live and learn I suppose. Hopefully others, with similar charging routines will benefit from our experience.

 

Regards

Richard

[Tony Brooks]

44 minutes ago, Richardcn said:

However, one cell of 3 (they're 6v batteries), was below minimum with plates exposed. I do check routinely, moreso in the summer, so this appears to be a problem with that particular cell. I

 

I agree, and individual cells dryer than the others tend to indicate internal short circuits, and it seems to me it is the shorting cells that produce Hydrogen sulphide. Probably time for renewal.

[Alan de Enfield]

50 minutes ago, Richardcn said:

This time, maybe because one cell is failing, I've been caught out but you live and learn I suppose

 

 

If a cell is failing and has an internal short you will find that the battery charger is working much harder (higher current) and for much longer that previously as it is, in effect, trying to put a charge in faster than it is 'leaking' (shorting) out,

The acid will be boiling away, the battery case will start to get warm, the battery terminals will get too hot too touch and the battery case ends will start to bow outwards.

The 'fumes' will start to corrode any metal in the vicinity and you may notice a 'greenish' tinge to the metal work, or even the start of a crumbly white powder coating (I'm sure you've seen it on old battery terminals).

 

The longer you leave it the worse it will get - the final indicator of an internal short is when the battery actually explodes spraying hot acid all around the engine room, and, onto anyone who is standing / sitting / working in the area.

 

Once you have identified (and accepted) you have a problem it can become quite dangerous, and very expensive to delay taking the battery out of the bank.

Not necessarily to replace it but just make sure you disconect it.

[Tony Brooks]

1 hour ago, Alan de Enfield said:

Not necessarily to replace it but just make sure you disconect it.

 

And its series pair - the OP says it is a 6V battery (3 cells).

[Richardcn]

Thank you for the wise advice gentlemen. I've seen no indication of external corrosion, excess heat or case distortion but I do have a temp probe fitted so I will monitor that more closely and carry out physical checks over over the coming weeks, once we're back in the water. Meanwhile charging voltages will be turned right down until we're back aboard.

 

There is the (small) possibility that I just underwatered that cell at the last top-up and so all may be well, if we're really lucky! However, I won't be taking any unnecessary risks and as we were on the verge of replacing them (due to reduced capacity) any sign of problems (now that they are fully watered) and they'll be off to the scrappy.

 

That will, of course, mean that I have to battle with SWMBO over cheap & 'consumable' versus not cheap & not so 'consumable'. Plus, if I were to win that particular 'discussion' then I'd have to consider Lead Carbon and revisit all that research. Do feel free to add your thoughts on that if you like.

[Tony Brooks]

My only comment is that with open cells you can use a hydrometer to check the state of charge of each cell, so in a day or two, once the acid and topping up water have mixed, if the cell readings differ by more than 0.030 across the cells then you have a faulty cell (Lucas said 0.025). If you get sealed cells then you can't use a hydrometer and boater testing involves fully charging, letting it sit overnight, then noting voltage, disconnecting, letting stand for a day or so and then comparing the voltages. Both should be almost the same.

 

Some here have been bitten by an earlier vendor of lead carbon batteries, so are likely to be somewhat biased. Carbon can't alter the chemical processes in lead acid batteries like sulphation, but it may well mask it.  especially with sub optimum charging.