Battery exploded

[73stagman]

As per the title.
I have been having "issues" with the Stag refusing to start recently (This week) Starts first crank with the booster charger but never after its stood over night or outside at work.
I thought the drive belt was slipping and so fitted a new one at work.
Drove the car home, around 7 miles, turned it off and restarted it no bother. As soon as I got in the house the misses wanted to go out to local shop .... went outside and turned the ignition switch the engine cranked for a very short time and then "BANG" white smoke pouring out from under the bonnet. Popped the bonnet to find the top of the "maintenance free" six month old battery in pieces and the remains of the acid dripping down the underside of the bonnet.
The panel above the battery is deformed upward and torn away from the side of the radiator support panel. (Not major damage but an amazing show of power!)

The symptoms before the explosion. The battery voltmeter always read over 13 volts when the engine was running. If the lights were turned on or the fan or even the windscreen wipers, the volt meter dropped to just below 13 volts and stayed there until the lights or whatever were turned off again. The volt meter then returned to the same level at just over 13 volts.

History.
The battery is 6 months old brand new at time of order.
The alternator was changed 3 months ago due to a continual "overcharge" state of the battery (in the red on the voltmeter) and eventual alternator failure. New alternator fitted and over charging issue no longer a problem
The car has been used every day since the beginning of August and has never, until now, missed a beat other than a slight hot under the collar incident at National Day during the world record attempt...

My own thoughts are that the damage was done when the alternator was overcharging the battery. I fixed the fault by replacing the alternator but I never checked the water level of the "maintenance free" battery afterwards.

I now think the battery fluid level has become too low due to overcharging by the old alternator. The new alternator has been charging fine but the battery has stopped holding its charge due to the low fluid level.
The booster starter has then continuously over charged the nearly dry battery this week until the gas pressure got higher than the battery casing top could hold...BANG

New battery required, copious amounts of water to flush out the acid deposits in the engine bay and a lesson learned.....
Don't believe "maintenance free" entirely. If there is ever any "overcharging" check the fluid level even in a maintenance free battery and as soon as there are any starting issues with your car always check the obvious things, loose battery cables, battery fluid level, drive belts before "bunging on the booster!"

Now off the road till the new battery arrives!

[tractorjames]

We blew a tractor battery up at home about a year ago. When its charging it gives off hydrogen gas (maybe not the case with a maintenance free battery????), The battery cover panel was removed to get the charger connected, other side of the shed we were grinding and a stray spark (or more like many stray sparks) blew it up.

For a while we wondered what had happened, the bang was louder than that of a 12 bore shotgun, after a few seconds all the acid was p***ing out of the battery box.

Luckily nothing was damaged and no skin was burned but it sure makes me careful with sparks and batteries now!

James

[73stagman]

A warning to those who fit the battery below the soft top and behind the rear seat..... The force of the explosion distorted a heavy gauge welded steel section in the engine bay and that contained the explosion.

I would suggest that the seat construction would not be so good at containing any explosion of the battery....and your kids may also be sat in that seat..

[PhilB]

I had a six volt battery explode under the back seat of a VW Beetle about 45 years ago...
I was driving along in town. The explosion was enormous, the sheer horror & shock lives in my memory still today.
The car stopped almost dead with the sudden power loss
Probably combination of build up of hydrogen gas under back seat plus a spark from the battery slowly working loose and touching some part of the frame
At least nobody hurt

[KOY 23]

Treat car batteries with respect, ok they are only 12v, so can't kill you but they can deliver a massive current and the burns from a red hot metal watch strap will be severe. when disconnecting always switch off everything to minimise at the chance of a spark and disconnect the earth terminal first.

[Guest]

We've had a few batteries blow up on our engines at work, as John says, they're only 12v but these had CCA of around 1100 amps! We no longer use this type as we nicked named them IEDs!!!

Jason

[flying farmer]

A mate of mine had a narrow escape a couple of years ago with a booster charger on a tractor battery, it exploded as he removed the charger. Fortunately for him the tractor bonnet contained the shrapnel as there was only the base of the battery left, and fortunately not a huge amount of acid either as it had been mostly boiled away by the booster being left on too long.

Neil

[tractorjames]

We were told at college if anyone gets done by a battery at close proximity (disconnecting/connecting a charger) just to throw as much water over them as soon as you can then run before you get a black eye

James

[edd]

Hope your back on the road soon Neil . Sad but good post I have certainly learned lots by it .
Edd

[Staghound]

Are we at risk using battery conditioners then? I keep a spare battery charged on one of these.

Andrew.

[Stagsongas]

There's far less risk if the battery being charged is vented, not sealed, allowing the lighter than air Hydrogen to escape.

That risk can be further reduced by disconnecting the power to the charger before the leads going to the battery are touched, as there is much less chance of a spark igniting any lurking Hydrogen. Keep in mind that Hydrogen is the most flammable and explosive gas in the Universe. I met a Lorry Driver some years ago with only one eye, guess how he lost the other one?

Regards

Steve

[Stagsongas]

A warning to those who fit the battery below the soft top and behind the rear seat..... The force of the explosion distorted a heavy gauge welded steel section in the engine bay and that contained the explosion.

I would suggest that the seat construction would not be so good at containing any explosion of the battery....and your kids may also be sat in that seat..

That's very good advice, and something I'll think about carefully as I planned to move my Battery. Maybe there's only one thing for it, move it into the boot like many manufacturerers have done.

Then again.....Petrol Tank, chain reaction.....hmmmm...

Regards

Steve

[pagan]

That's very good advice, and something I'll think about carefully as I planned to move my Battery. Maybe there's only one thing for it, move it into the boot like many manufacturerers have done.

Then again.....Petrol Tank, chain reaction.....hmmmm...

Regards

Steve

Also
Battery leaks,,,,, battery acid everywhere. as probably not a problem because Stags don't have rust problems.
Used to Mini's (the real ones) , battery in boot, always rusts.

If you do move it to the boot, you need a large diameter battery cable for the starter.

Also
I've never connected a battery charger whilst live....
If the wire touches some other component or part on the way...

Allan

[73stagman]

In the boot of my X5 there are two lead acid batteries! Put there by the manufacturer. One is a 110Ah massive 120 quids worth of BANG and the other is a back up for the alarm.. its only small at about half the size of the main battery. they are both secured below the rear floor and under the spare wheel and bolted down with a steel upside down pudding bowl affair..... Properly bolted down aswell.
I will be checking the fluid level on them before it goes back to the road in January! (Probably have to replace the bigun anyway)


Remember my battery did not explode whilst it was being charged.... it exploded whilst it was being discharged by the starter motor!!!
The point of that comment is that you wouldnt be "venting" the battery whilst you were trying to start the car. So the charging procedure is not under question in this instance but its clear that charging is not the only time to be meticulous!
So the damage was done by neglecting the basics after it became clear that the battery was being over charged by the original alternator even though the actual event happened some time after that!
I mean, it is clear that I knew the battery was overcharged by the faulty alternator. I did nothing about that. I just fixed the alternator where I should have also then checked the rest of the charging system including the battery and all the cables attached to it.

[Jeff]

There's far less risk if the battery being charged is vented, not sealed, allowing the lighter than air Hydrogen to escape.

That risk can be further reduced by disconnecting the power to the charger before the leads going to the battery are touched, as there is much less chance of a spark igniting any lurking Hydrogen. Keep in mind that Hydrogen is the most flammable and explosive gas in the Universe. I met a Lorry Driver some years ago with only one eye, guess how he lost the other one?

Regards

Steve

Got poked in the eye with a stick?