# Exploding Battery Warning



## luckyshot (May 1, 2005)

For the last few weeks there was a smell of hydrogen inside the van, couldn't figure it out, today one of the leisure batteries exploded.

On looking for the reason we found that if you have the switch on the Elekroblock on the wrong battery type i.e. lead acid and you have a gel battery or visa versa it can possible cause this to happen.
A build up of hyrdogen due to overcharging.

So if you change your batteries from lead to gel or have bought a second hand van - check your switch is on the right type of battery.

We bought the van 2nd hand and the previous owner must have put new gel batteries on and not changed the switch over.

If you have a problem with battery acid - bicarbonate of soda with neutralise it.


----------



## JeanLuc (Jan 13, 2007)

I am not an auto-electrician, so the following should not been taken as absolute advice. However, it may be of use and I am sure another poster will point out anything I may have got wrong.

Hydrogen is an odourless gas, so what you have been smelling is hydrogen sulphide. I had this problem when one of the cells in a gel battery failed last year. Whilst it is of course important to set the switch on an Electrobloc to the correct setting, on my EBL99 at least, the setting does not affect the charging voltage. That is capped at 14.3V which is below the gassing voltage for both gel and flooded lead-acid types. What does change is the length of time the charger operates in stage 2 of the charging cycle (8 hours for gel; 1 hour for LA). So, if your EBL was set to LA but had gel batteries fitted, the effect would have been to consistently undercharge the gel batteries.

I would suspect a failed cell was the cause of your problem. I replaced my Exide Gels with 2 x Elecsol 110Ah. The switch for these should be set to LA (Blei-Saure). To prevent the risk of gas leaking into the interior of the motorhome in the event of another cell failure, I have the batteries fitted with vent tubes to the exterior.

Philip


----------



## gromett (May 9, 2005)

I was going to say you can't smell hydrogen it was probably hydrogen sulphide ie rotten egg smell. but was beaten to it.

General rule of thumb is if you smell something you shouldn't check it out unless you have a dog or smelly other half then hydrogen sulphide is normal.

Good advice on checking that the settings on your battery charger are correct though. makes quite a bit of difference.

Karl


----------



## sallytrafic (Jan 17, 2006)

The first smell you get from an over charging but otherwise serviceable battery is more a prickling sensation and taste rather than a smell. It's caused by the minute bits of Sulphuric acid borne into the air by the gassing. As others have said Hydrogen (and Oxygen) have no smell. By the time you smell hydrogen sulphide its indicative of a much worse problem. Hydrogen Sulphide is a very poisonous gas luckily we can smell it in concentrations lower than the lethal dose.


Before trying to neutralise battery acid a wash down with lots of water is recommended. 


Note also that battery acid is fairly dilute but the water part will evaporate over time and the tiniest part will eventually become concentrated enough to eat fabrics. Ask anyone who has worked in a battery shop overalls peppered with holes.

Oh and some chargers give a different end voltage for LA and Gel.


----------



## CliveMott (Mar 10, 2008)

Irrespective of the battery type it is always best if the battery compartment is vented outside. I know that a pair of batteries crammed under the front seats make this difficult but the advice remains.
C.


----------



## luckyshot (May 1, 2005)

*Exploding battery warning*

Thanks for your advice am just off now to replace battery


----------



## DABurleigh (May 9, 2005)

CliveMott said:


> Irrespective of the battery type it is always best if the battery compartment is vented outside. I know that a pair of batteries crammed under the front seats make this difficult but the advice remains.
> C.


I disagree, Clive!

But only in the fact it is not difficult  A minute with a drill, a grommet or hot glue gun, windscreen washer tube from Halfords, and venting is sorted 

Dave


----------



## CliveMott (Mar 10, 2008)

Nice one Dave.
C.


----------



## pippin (Nov 15, 2007)

So, how to know if there are battery problems looming in the first place so that you can pre-empt explosions?

Monitoring!

It may be rather impracticable to feel the temperature of or to sniff around a battery as it is being charged.

What you can and should do is keep an eye on the voltmeter.

Check the voltage when it is on mains hook-up charge - it should be around 13.8V to 14.0V after a while.

Then switch the mains off and watch what happens to the battery voltage.
It should drop fairly quickly, even without a load, down to 12.8V-ish.
If it drops much lower - the battery has problems.

Switching on a load of a few amps (lights, pump - whatever) should not cause the voltage to drop significantly in the immediate short term.
If it does then the battery has problems.

If the battery is accessible, try feeling all along the side when it is being charged.
If there is a warm spot then that cell is on the way out.

The only equipment needed for the above checks is MK1 nose, MK1 hand and MK1 eyeball to look at the built-in voltmeter in the van.

Me? If I was really keen and the battery is wet-acid (even gells are lead-acid) I would be taking specific gravity readings of each cell once a month and keeping a log of them.

Which is what I had to do with two banks of 24V 144AH cells that were the emergency radio batteries on board the merchant ships I sailed on in the 60's-70's. 
A right old chore that, a total of 48 readings each month as we had to do it before and after charge!


----------



## Stanner (Aug 17, 2006)

pippin said:


> MK1 eyeball to look at the built-in voltmeter in the van.


 :? What voltmeter :?


----------



## pippin (Nov 15, 2007)

You should get a Hymer - the instrument panel has one!


----------



## TDG (May 26, 2009)

pippin said:


> ........The only equipment needed for the above checks is MK1 nose, MK1 hand and MK1 eyeball to look at the built-in voltmeter in the van......
> ...Which is what I had to do with two banks of 24V 144AH cells that were the emergency radio batteries on board the merchant ships I sailed on in the 60's-70's....


Ah! The Mark I eyeball - the first tool out of my tool box but unfortunately often is not too much use for people with no technical inclination.
Big battery banks still exist on ships. I'm currently involved building some powerful tugs and we use 2 x 24 volt 400 AH batteries to start the 2000hp engine. The instantanous starting current is >2500A when the engines are stone cold!
Best regards (to an ex R.O. ?)


----------



## gromett (May 9, 2005)

My battery charger has a separate wire which goes to the negative terminal to monitor the temperature I am pretty sure that this along with the voltage monitor will keep me safe with the sealed batteries  (crosses fingers just in case)

Karl


----------



## Stanner (Aug 17, 2006)

pippin said:


> You should get a Hymer - the instrument panel has one!


Is that the same with Burstners?


----------

