Battery Fumes like rotten eggs!

[Morganboy1]

I have had our Swift Bolero at home on the drive for several days on EHU. A couple of days ago as I walked past the MH I heard the Carbon monoxide alarm chirping, but didn't at that time notice any smell of gas, so as a precaution I fitted new batteries to the alarm before we depart for Spain on Sunday from Poole. Today when I opened the hab door I immediately noticed a pungent strong smell like 'rotten eggs'. I thought at first I had a gas leak remembering the problem with the carbon monoxide alarm a couple of days earlier. The gas was turned off, and after checking all over the MH no apparent leaks were evident, however the smell seemed to come from the battery area which is mounted under the lounge seat at the rear near side. I then noticed the battery was quite warm, and the posts quite warm to touch. I immediately disconnected the EHU and opened the roof vents. Once the fumes had dispersed, I removed the 100amp battery as I imagined it had problems and had been overcharged somehow. As we are crossing over to Cherbourg on Sunday and then onto Spain for 6 weeks I thought it best to replace the battery with a new 110amp one. I did not want to leave our young springer locked in the MH for 4.5 hours during the ferry crossing with a battery fault, or indeed use the MH ourselves as the fumes could have been highly inflammable and quite dangerous.
So why had the EHU cooked the battery in the first place, (we also have a solar panel fitted), does the onboard charging system not regulate the amount of charge being put in the battery?. Was the battery on its last legs and in need of replacing anyway. It's a sealed battery so I cannot check the levels inside to see if the plates are covered like you used to be able to do. Do I have a problem with the charging unit on the MH? We've never experienced problems before leaving it on EHU for periods of time. Any thoughts?

 

[tonyidle]

One of the many ways a battery can die is when one cell short-circuits internally. You then have a 10v battery being charged as though it was still 12v. The rest of the cells eventually dry up and as they're doing so the rotten egg smell is given off. You took the correct steps when you found the dying battery.

I wouldn't suspect the charger at this stage. Just keep an eye on battery voltage as it charges. The voltage shouldn't exceed 14.5ish volts and should settle to 13.8ish. Don't get hung up on precise voltages -- if the charger is faulty it will be nowhere the voltages I've mentioned.

 

[TheBig1]

the battery was already failing so got cooked as it did not reach the correct charged voltage. hydrogen sulphide is the part you smell but the big danger is the explosive hydrogen produced

 

[Minxy]

They don't half stink don't they!

We had a battery fail within 2 years and it was replaced by the manufacturer without a problem, it does happen but quite infrequently fortunately.

Without knowing how old your battery is it's difficult to say for sure but I suspect its just reached the end of its life and needed replacing.

Personally I wouldn't leave the EHU on all the time, IMV it's better to have it coming on every now and then each week, rather than on continuously.

 

[PeteH]

You did all the right things, get a new battery fitted, keep an eye of the charging regime for a few days or so until you are sure there is not a fault there. Carry on enjoying the `van.

Leaving the EHU on when parked up long-term, is something that has been debated for years, I tend to do it, have done for many years, long before "smart" chargers, as do many others, so long as the Charging unit is sophisticated enough to detect when a battery wants charge (or not), it does not seem to affect battery life as much as NOT having at least periodic charging. The large majority of "modern" vehicles have built in "drains", Clocks, Alarm and Tracking systems, even some EMU`s, so battery "maintenance" is essential. BTW, some of the "cheaper" Solar chargers can allow overcharge, fortunately not such an issue in a "British" winter!.

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[Camdoon]

We have an inboard battery for the first time and it is a gel. Are they not more suitable or does it not matter?

 

[Gromett]

This can also happen if you have one of those smart solar controllers that work on both 12 and 24V.
If the controller gets disconnected from the batteries, you need to disconnect the solar panels before reconnecting the solar panels.
If you don't then some of them will read the incoming voltage from your solar panel and then assume because you have over 15v that you have a 24V system.
Then when you connect your batteries they pump 24V into the 12v batteries.

Not all dual voltage controllers do this, but I have seen this happen two times so far on different vans.

 

[Gromett]

PS: it is also possible the solar controller has failed and is pushing the 17+ volts directly into the batteries.

 

[Southdowners]

We had that happen in a caravan we owned. The smell was vile. It turned out to be the battery dying. You did the right thing.

 

[PhilandMena]

You don't say what type of battery it is, how long it has been in use, so it's difficult to make an accurate estimate of the cause of failure. If your replacing with a Lead Acid battery make sure your on board charger is set for Lead Acid and you check your electrolyte levels every so often and top up as necessary.

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[scotjimland]

Personally I wouldn't leave the EHU on all the time, IMV it's better to have it coming on every now and then each week, rather than on continuously.

Agree..

I followed that rule for many years with no problems.. then just after Christmas I checked the batteries and the starter battery was almost dead.. I suspected not enough sunshine for the solar to keep up with the drain of the Strikeback alarm... but no matter ..

I put them on charge and checked after a couple of days.. all is well.. all back to full voltage, so left the charger on and thought no more about it .. a couple of weeks later I was back out checking and there was a loud chattering from the EBL and it wasn't charging.. (I did a thread about having it repaired at Apuljack )

Coincidence .. perhaps , it's an old EBL so perhaps on it's way out and I just hastened it's demise.. who knows, but Schaudt give the same advice.. I emailed Udo for advice, put on charge for a couple of days a month.. leaving on permanently can shorten the life of the EBL.

 

[DavidG58]

Hope your new battery solves the problem

But just to refer back to a comment in the first post, carbon monoxide has no smell, if the alarm goes off you will not smell gas

It could be that your chirp was a coincidence and was just low battery voltage, I always suggest a CO monitor / alarm with display so you know how big the issue is

 

[Spriddler]

It could be that your chirp was a coincidence and was just low battery voltage,

Agreed. If it's activated it should make a lot more noise than just a 'chirp'.
There should a 'Test' facility which produces the alarm volume.

 

[Terry and Jan]

Same happend to me a couple of years ago, luckly being ex electrician i knew what the smell was.

 

[Just smiffy]

Also to add, if your battery has a vent tube outlet, always make sure you put a vent tube on and vented to the outside...
Even if it states no vent necessary, if it’s got an outlet then put one on...

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[Revolvor]

Personally I wouldn't leave the EHU on all the time ...

I didn't want to keep my MH on permanent charge from the EHU, so have wired an intelligent Battery Maintainer to the Cab Battery. The advantage of that is that with my B2B Charger, it also charges the Hab Batteries too. Only a very low current, shared between three batteries, but overcomes any drain from Radio/Alarm/Tracker etc. The Hab batteries also get a boost from the Solar Panel if the sun shines!

 

[Speve]

When on a campsite pitch for longer stops the hook up is on all the time without problems I suppose you could say you are using the power more then than when van laid up for winter but never had problem leaving on hook up for long periods.

 

[PhilandMena]

When on a campsite pitch for longer stops the hook up is on all the time without problems I suppose you could say you are using the power more then than when van laid up for winter but never had problem leaving on hook up for long periods.

Ditto! and when on the drive at home.

 

[gus-lopez]

It's a sealed battery so I cannot check the levels inside to see if the plates are covered like you used to be able to do.

You can lever the one piece top up with a large knife .

 

[Minxy]

I didn't want to keep my MH on permanent charge from the EHU, so have wired an intelligent Battery Maintainer to the Cab Battery. The advantage of that is that with my B2B Charger, it also charges the Hab Batteries too. Only a very low current, shared between three batteries, but overcomes any drain from Radio/Alarm/Tracker etc. The Hab batteries also get a boost from the Solar Panel if the sun shines!

When we have our camper on EHU it charges both the hab and cab batteries, as does the solar panel. We have our EHU lean on a timer in the garage so just set it for how often and how long we want it on and then we can just forget about it as it'll look after itself.

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[Revolvor]

When we have our camper on EHU it charges both the hab and cab batteries, as does the solar panel. We have our EHU lean on a timer in the garage so just set it for how often and how long we want it on and then we can just forget about it as it'll look after itself.

I have to manually select Cab or Hab battery on mine. The CTEK Solar Controller will trickle charge Cab battery when Hab is fully charged, but MH is parked in total shade in the Winter, and never fully charges.