Hi all
I went out and tried to start up my Mondeo today (97MY Verona)
and as I turned the key there was a loud bang and a plume of smoke emitted from the front left of the bonnet (where the battery is).
I had a look and the battery had literally exploded chucking/dripping acid around the inside of the engine bay - the securing bracket held what was left of the case in situ.
I called the RAC and 40 mins later they were out , and replaced the battery for me...he also flushed out where the battery had been with water.
RAC man said that he's seen this in about 1 in 300 cars and its usually the lead plates connecting and igniting the gas that causes it - any one else had experience of this?
As far as I can tell the old battery was the original one that came with the car when new.
I've had it two years now and todays "incident" is the only blot on an otherwise pretty clean copybook :0)
I had to adjust the pacemaker I can tell you!!!
Thanks
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A friend had a Montego diesel where the battery exploded on start-up, the thought then was either, the lead plates in one of the cells buckling/shorting, or possibly the internal cell connecting lead bars suffering a bad/sparking connection.
The eventual by-product was a very rusty engine bay even though the bay was more than 'swilled out with water'. The acid left behind would have to be neutralised carefully, perhaps one of our 'chemistry' contibutors could help here? (or a battery manufacturer?) Good luck.
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chances are a lot of it would need careful re-spraying and/or rust treatment as the paint would undoubtedly have been damaged. If paint and battery acid have a fight, I know who will win all of the time...
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To neutralise battery acid, I\'d recommend sodium bicarbonate (baking soda). It\'s weakly alkaline, so won\'t do any damage, but it\'s alkaline enough to neutralise acids. You\'ll be able to see when it\'s neutral beacause it froths like mad with acid.
Andy
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Scoreline:
Andy P 0, Swear Filter 2
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I don't know why the thing does that, I've argued with it until its edited me. I wish we didn't need the thing at all, but sadly we do.
However, I've changed it back.
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Mark
I take it that the swearword recognition IS set up to look for :
"(space)naughty word(space)" and NOT just "naughty word"
The incorporation of the leading and trailing spaces often sorts out misidentifications.
HTH
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I blew up a battery once, in about 1985. I turned over the engine of a Talbot Sunbeam having left a big spanner on the battery. The spanner moved, spark, bang.
The explosion rattled near-by windows. The big spanner landed about 40 feet away. There was about 4 inches of the bottom of the battery casing left, which was about the level the acid was at.
This was a 'sealed-for-life' type battery, so you weren't meant to check the electrolyte level. I think there was very little liquid in the battery, leaving a large space for an explosive mixture of hydrogen and oxygen to accumulate. Since then I've had a preference for the batteries with little screw on covers so you can see the level of the electrolyte in the cells.
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Scary stuff, that's why you should wear eye protection when handling/inspecting batteries
MG-Rover Questions? forums.mg-rover.org/
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In your case it was probably the spanner that shorted out the terminals. The instantaneous current draw could well have been in the 1000s of amps, causing the electrolyte to boil and the battery to explode under the pressure. This is normal if you put a spanner across a car batterys terminals!!!
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How do you know it's normal, Cyd, have you tried it too?
It would probably take several seconds to vaporize the 300 to 500 mls of electrolyte that seemed to be missing from the remains of the battery. The explosion was virtually instantaneously after I had turned the ignition key. The remaining electrolyte wasn't hot, so I think it unlikely that the elctrolyte had boiled. I'm fairly certain that this was an explosive ignition of the gases in the battery, but I'm not going to repeat the experiment.
Curiously, the spanner had no burn marks on it, which I'd have expected if I'd passed lots of amps through it. I still have the spanner.
And yes, it was a stupid thing to have done, but I was young(er) and stupid. Why else would I have had a Talbot Sunbeam? I record the story in the hope that others may learn something from my experience.
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It isn't necessary to boil 500ml of electrolyte to cause an explosion,just a few cc's. 1cc of water when boiled produces 1700cc of steam - if the volume is contained at 1cc then the pressure will be 1700x original.
Now, a car battery is 12volts. Power = volts x amps. If you short out the terminals and the current instantly reaches, say, 1500 amps that's 18,000watts or 18kW. This heat input only has to boil a cc or two of electrolyte and WALLOP - you've got a pretty impressive explosion in very short order. The heat is very localised because it doesn't have time to spread around the bulk of the liquid by convection.
It was one of the first things they taught us in Motor Vehicle Maintenance - never, never, NEVER short a battery; people have died doing so.
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Don't try this at home on a nuclear reactor, either.
That's how the Ruskies blew up Chernobyl.
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Cyd my friend, you are missing the moral of my seemingly pointless anecdote. I didn?t intentionally short the battery and I cannot imagine why anyone might want to do so.
However, most of us have, at some time, needed to jump-start a car. There is a note on the correct procedure in the front of the Haynes manuals. Many of us would have difficulty in recalling the correct procedure and it is unlikely that we would have a manual to hand when a battery expires, which invariably occurs in the dark and when it?s raining.
The procedure is positive (live) to positive, negative terminal (earth) of the donor car?s battery to an earth point on the recipient car, well away from the battery. This final connection completes a circuit and is likely to strike a spark, so it is made well away from either battery. The spark could otherwise ignite an explosive mixture of hydrogen and oxygen in the battery casing, showering the operator?s face with plastic shrapnel and sulphuric acid.
Whilst this explosion might have been caused by a build-up of steam pressure, I think it is unlikely. Before you could generate any steam, you would have to boil all the electrolyte. The remaining electrolyte wasn?t noticeably hot. Assuming an 18kW current and 0.25 litres (about half a pint) of liquid in the battery, I reckon it would take 4.6 seconds to boil the electrolyte, assuming it had a specific heat capacity of 4.2 kJ/kg K and it had been at 20 degC (the boiling point and specific heat capacity of water are used here). This was one of the few things I learnt when I did my engineering degree. This explosion was instant. It was probably a gas explosion.
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"There is a note on the correct procedure in the front of the Haynes manuals. Many of us would have difficulty in recalling the correct procedure and it is unlikely that we would have a manual to hand when a battery expires, which invariably occurs in the dark and when it?s raining."
Not only is there a danger of big bangs, but many drivers have fried their circuits (BMW owners take note!) by incorrect jump starting!
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