Battery Exploded

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Battery Exploded

Post by wanje » 26 Mar 2006, 16:13

Hello everybody,
My dad's Citroen Evasion is now sitting in the garage after being towed. The battery exploded the day before on some street upon my dad turning on the ignition. He's still in a trauma as it was scary experience. He's worried if he puts in a new battery and start again, the same thing might happen.

Now, a battery exploding is a very rare case, most of the time it just goes dead when the time comes, right ? A friend said it could be the alternator overcharging the battery and he was mentioning the alternator and regulator needs replacement. My dad still has doubts. He's trying to learn the exact reason so that such thing will not recur in the future. Has anybody experienced the same thing and what was the exact reason ? The wiring has not been touched since he bought the MPV.
:( Wanje

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Battery Exploded

Post by AndersDK » 26 Mar 2006, 16:23

The battery wont explode by generator faults on starting. Thats more likely to be a problem with the starter motor circuits and associated cabling.

This is because the charge circuit cabling from generator is not that heavy gauge - it would burn out before the battery explodes. But the starter motor cabling is very heavy - often 10mm2

If the starter motor jams (will not crank the engine but still tries) - then a LOT of power is drained from the battery and could very well make it boil so fast it literally explodes.

I once had a similar scaring problem on my CX. The cable eye carrying +12V battery live to the starter motor engaging coil - was naked just at the edge of the coil body. This meant that when I tried starting - the small vibrations made the cable short out to the coil body.
Made a sound like a machine gun - and smoke from engine bay :shock:

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Battery Exploded

Post by Peter.N. » 26 Mar 2006, 16:43

Agree with Anders (again) It could be that the connections were not tight and caused an arc which ignited the hydrogen being liberated by the battery while it was being charged/discharged. If you have or can get the old battery, check its condition, if the just the casing is broken but the plates are intact, the the above will probably be the case. Just make sure that the connections are clean and tight.

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Battery Exploded

Post by Mandrake » 26 Mar 2006, 19:03

While the above replies are definately possibilities, another possibility if the battery has been overcharged long term, is there may have been internal damage to the battery such as warped and/or flaked plates.

The spacing of the plates is so close in a normal battery that if they warp enough they can short out internally - once this happens there is no way to prevent a catastrophic meltdown or explosion inside the battery.

The heating caused by the starter current could have been enough to be the final straw that allowed the plates to touch.

I don't believe that a jammed starter motor held on for a few seconds would be enough to cause an otherwise good battery to explode. Stalled current of a starter motor is typically only about twice that of the cranking current, and most people won't hold it on if they don't hear it turning over.

I would definately be checking out the heavy wiring to the starter to make sure its not shorting somewhere, check the battery terminals are tight, and also carefully check the charging voltage when the new battery is fitted to make sure it is correct, other than that I don't think you have to worry too much about it reoccuring...


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Battery Exploded

Post by rossnunn » 26 Mar 2006, 19:54

I've just read this post out to the old man, he's seen it before. A guy had just had his car serviced & had fitted a new starter motor. He drove it round the block and all was well, when he wen't to start it again there was a almighty bang and the battery split clean in half.
Turned out that he'd routed the battery cable to the starter too close to the exhaust, it had burnt through & earthed on the exhaust, the result was a lovely bit of weilding and a battery in two halves.
Check that you are not getting earths down the main (big) positive battery cables before you connect your new battery.

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Battery Exploded

Post by fastandfurryous » 26 Mar 2006, 21:47

A friend of mine had this happen to him. Drove to tescos, no problem. Went to start the car, and as he turned to "start" there was no cranking, just an almighty bang as the battery blew both ends out.

Turned out there was nothing wrong with the car.. the battery had just had it. Changed for a spare, and the car started and was fine thereafter.

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Battery Exploded

Post by Kowalski » 26 Mar 2006, 22:16

Lead acid batteries produce hydrogen when you charge them (even the sealed ones) if it gets ignited that can make your battery explode.

My Dad exploded one in the garage last summer disconnecting the battery charger from it. It made quite a mess in the garage, blew most of the top off the battery (which was a truck battery incidentally) and some of the side walls. He said his ears were ringing afterwards too, he was ok apart from that. Its kind of ironic really considering he warned me about that sort of thing happening and that I should turn the charger off before connecting or disconnecting the battery from it then didn't follow his own advice.

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Battery Exploded

Post by NiSk » 28 Mar 2006, 13:27

Assuming the battery really "exploded", I would also be very worried about a couple of litres of concentrated sulphuric acid having been sprayed all over the inside of the engine compartment - talk about accelerated corrosion!