Batteries on their way out???,

[sharpness]

Good evening

I visited the boat this morning, first time for 2 weeks, not to stay unfortunately. When I opened the slide there was a good whiff of bad eggs, hydrogen sulphide?, never had that before.

The set up is trad stern with 3 x 110ah batteries on the swim next to the engine. There is a Sterling 30a charger hard wired and permanently on shoreline when we are in the marina.

The batteries are Numax 110ah CXV sealed, 3 years old. The normal pattern of usage is lots of weekends & a few weeks away in the summer always leaving with a full charge, plugging back onto the shoreline on return.

Unusually this morning the Smartguage showed only 91% charge, a multimeter on each battery showed 12.64V but wouldnt I expect them all to be the same as they are all connected?

There was nothing outwardly visibly wrong with any of the 3 batteries, no leakage, bulges or splits visible. Two of the batteries were cold to the touch, one, the one "nearest" the charger was slightly, only slightly, warm. For what they're worth, not a lot I understand, the indicators were green on 2 of the batteries, nothing visible on the 3rd, the slightly warm battery.

Any suggestions please?

Thanks

 

Steve

[Hey Ho]

From your thread title I thought a miracle battery replacement had been invented. Wrong end of the stick there then...

 

On the Hydrogen sulphide smell, I've only ever experienced that when a battery has been seriously overcharged. It's unmistakable & it definitely stinks! Others will be along with better detail, but to me it sounds like overcharging.

[Taslim]

Others better informed than I will be along soon enough but I think you have answered your own question.

 

The battery that is the odd one out is prob Donald Ducked.

 

I've just had similar and, although the batt looked OK, a prod about with hydrometer and multi meter showed it was gone.

 

The others seemed alright so, being skint (what's new),I replaced it as like for like and all seems well so far. My fear is that the others could drag the new one down but I have done individual charges and checks on self discharge rates and they all compare so fingers crossed.

 

Have you checked electrolite levels in the individual cells on the 'suspect'. That will give you a clue.

[ditchcrawler]

I would suggest you completely disconnect the smelly warm one and I bet you will find its voltage at about 10.5 volts by the morning

[sharpness]

 

Have you checked electrolite levels in the individual cells on the 'suspect'. That will give you a clue.

Cant do that unfortunately, sealed & nothing I can remove to have a look.

Thanks for the thought though.

 

Steve

[PhilR]

Good evening

I visited the boat this morning, first time for 2 weeks, not to stay unfortunately. When I opened the slide there was a good whiff of bad eggs, hydrogen sulphide?, never had that before.

The set up is trad stern with 3 x 110ah batteries on the swim next to the engine. There is a Sterling 30a charger hard wired and permanently on shoreline when we are in the marina.

The batteries are Numax 110ah CXV sealed, 3 years old. The normal pattern of usage is lots of weekends & a few weeks away in the summer always leaving with a full charge, plugging back onto the shoreline on return.

Unusually this morning the Smartguage showed only 91% charge, a multimeter on each battery showed 12.64V but wouldnt I expect them all to be the same as they are all connected?

There was nothing outwardly visibly wrong with any of the 3 batteries, no leakage, bulges or splits visible. Two of the batteries were cold to the touch, one, the one "nearest" the charger was slightly, only slightly, warm. For what they're worth, not a lot I understand, the indicators were green on 2 of the batteries, nothing visible on the 3rd, the slightly warm battery.

Any suggestions please?

Thanks

 

Steve

 

IME, battery voltages vary quite a lot between manufacturers/battery types.

My starter battery reads just over 13 volts when fully charged.The leisure batteries read 12.75 volts.

 

Whenever I have fitted a new battery I have noted the voltage when fully charged to use as a base point. I have found this a reliable method of monitoring the batteries during their life.

Edited March 2, 2014 by PhilR

[Keeping Up]

I also believe that the warm one is useless, and that if you disconnect it from the others you would find that it falls to 10.5 volts within a few hours because one of its cells has become a short-circuit. The gas is coming from the remaining 5 cells of the battery which are being overcharged as they struggle to get to 2.53 volts per cell (12.64 divided by 5).

 

Beware that if you can smell the gas, there is almost certainly a build-up of an explosive mixture of hydrogen and oxygen gases, so apart from the risk of the faulty battery overheating and spilling acid everywhere there is also the risk of explosion if you continue to charge it. You should stop charging, ventilate until the smell goes away, and then disconnect the suspect battery. You should find that the other batteries can then be charged to well above the 12.64v that you are seeing

 

Note that it is perfectly OK to replace just the one faulty battery, the others may be low in capacity but would not damage the new one or prevent it from charging - unless and until one of them too develops a short-circuited cell. It is however better to change them all if funds allow

[Androo]

I would suggest you completely disconnect the smelly warm one and I bet you will find its voltage at about 10.5 volts by the morning

That's what happened to me. Disconnected it, measured the voltage (10.4) did a hydrometer test and it came up 1 cell dead.

[sharpness]

Thanks for all that, pretty well confirmed what I thought.

I went back to the boat this morning, its only 20 mins away. Same eggy smell & although the charger was on float the Smartguage only showed 51% charge. I've switched it all off for now & hopefully I'll be able to get down there for a few hours next weekend to sort it. I think I'll probably replace all three, if ones gone at 3 years it hasn't done too bad & the other 2 might not be far behind.

Thanks again.

 

Steve

[ditchcrawler]

Thanks for all that, pretty well confirmed what I thought.

I went back to the boat this morning, its only 20 mins away. Same eggy smell & although the charger was on float the Smartguage only showed 51% charge. I've switched it all off for now & hopefully I'll be able to get down there for a few hours next weekend to sort it. I think I'll probably replace all three, if ones gone at 3 years it hasn't done too bad & the other 2 might not be far behind.

Thanks again.

 

Steve

They will probably be flat by the weekend.

[billh]

From your thread title I thought a miracle battery replacement had been invented. Wrong end of the stick there then...

 

That's what I thought too.There is indeed a replacement for a starter battery used for diesel engines for railway applications, As I understand it, a super capacitor plus a mass of supporting electronics has been developed which can provide sufficient energy to start the engine. Don't ask me how it works , far too modern!

 

Google: MTU CaPoS

Edited March 3, 2014 by billh

[Androo]

 

. I think I'll probably replace all three, if ones gone at 3 years it hasn't done too bad & the other 2 might not be far behind.

 

 

That's the best option to replace the lot. If you mix match, a bad cell in just one of the old batteries can ruin your new one.