# strong smell from batteries



## dcummin (Jan 21, 2008)

Got an imense pong coming from my leisure batteries. Im assuming had it and was just going to replace them both as they are probably pretty old

I did a quick google first and even though it is possible its just the batteries that have had it - it could also be that that they are being overcharged.

(Currently I leave my motorhome hooked up to mains - as I have a small oil rad on a timer for the cold evenings)

How do I tell if there is too much charge going to the batteries - I would hate to buy new ones and the same thing happen again

many thanks


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## rosalan (Aug 24, 2009)

Batteries do give off a smell which is harmful!
They should be vented outside of the van at all times unless they are the fully sealed type.

Alan


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## erneboy (Feb 8, 2007)

First of all turn your charger off. Then do not do anything for several hours till the smell has gone. You may cause an explosion if you work on them while they are still gassing.

Then you will need to test the batteries to determine their condition. A drop test would be best. Search on here for how to do it, Alan.


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## centrefire (Apr 23, 2007)

It sounds as if they have been " cooked" that is overcharged. Vent out the van as already stated. It happened to me when the charge unit became faulty and pumped too much charge into the one leisure battery I had at the time. I got a severe sulphur smell and the walls of the battery swelled out . I was very lucky it did not explode. That is one of the reasons I do not leave the van on continous charge. I only give it a charge for a few hours before any trip. Be very careful and do not work on the terminals until that smell has cleared. I am not an expert but that is my advice.


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## dcummin (Jan 21, 2008)

centrefire said:


> It sounds as if they have been " cooked" that is overcharged. Vent out the van as already stated. It happened to me when the charge unit became faulty and pumped too much charge into the one leisure battery I had at the time. I got a severe sulphur smell and the walls of the battery swelled out . I was very lucky it did not explode. That is one of the reasons I do not leave the van on continous charge. I only give it a charge for a few hours before any trip. Be very careful and do not work on the terminals until that smell has cleared. I am not an expert but that is my advice.


many thanks

Is there any easy way to tell if it is my charger or just a duff battery? - my vehicle is a bit on the large side just to pop down to a local garage etc


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## BillCreer (Jan 23, 2010)

Most common problem that causes overcharging is when one or more of the cells becomes defective. As the voltage then never reaches a level where the charger turns itself off the charging continues and will boil the battery dry.

Have you any way of checking the battery voltages?


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## dcummin (Jan 21, 2008)

BillCreer said:


> Most common problem that causes overcharging is when one or more of the cells becomes defective. As the voltage then never reaches a level where the charger turns itself off the charging continues and will boil the battery dry.
> 
> Have you any way of checking the battery voltages?


ive not im afraid - and to be honest im a bit waring of doing anything with these batteries other than remove them and safley dispose.

They look like theyve been there for some time - and ive been a bit daft and left them charging for weeks - so im thinking that your defective cell suggestion is a verly likely cause.

Ive ordered a couple of identical replacements (to be on safe side) which ill pop in when they arrive - and then be careful on charging etc until im next at the rv dealer in the spring - think ill have one of the more advanced battery chargers installed


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## BillCreer (Jan 23, 2010)

Just for the record:-

> 12.80 V 100% 
approx. 12.55 V 57% 
approx. 12.32 V 50% 
approx. 12.18 V 25% 
< 12.00 V 0% 

The measurements should be performed several hours after completion of charge when the charge state has stabilised.


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## dmet (Mar 25, 2013)

And never smoke near or expose you battery to a naked flame

Dave


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## listerdiesel (Aug 3, 2012)

If you can get over to us at Rushden, I will check the charger out for you.

Peter


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