Exploding batteries!

[CalicoJack]

On Sunday afternoon, I went to start, for the third time that day, our Perkins 4108. As I turned the switch to start there was a loud bang and the engine compartment filled with smoke. Closer examination showed that part of the top of the starter battery had blown off (Too much curry perhaps?!)

I expected that this had wrecked the electrical system. The starter battery would light up the ignition light but would not engage the starter motor. When I connected the domestic battery by using a jump lead from the positive of the domestic to the positive of the starter battery to my great surprise and relief the engine started as normal and took us home.

Any thoughts as to the cause of the battery explosion?

 

[hightech]

Had you been on a shore supply charging the battery prior to the problem?? If so then their might have been a hydrogen build up and a spark set it off. You got off lightly, could have been much worse!

 

[Guest]

A few years ago a man returning to a boat after leaving the charger on and found that the lights would not work.

So he lit his lighter to find the breaker. The gasses from the overcharged batteries blew up in his face and exploded the batteries all over him.

We arrived at the Marina to find no security and blood on the walls of the office.

The simple suggestion is the batteries were gassing and the starter motor ignited it. Were you equalizing them?

 

[CalicoJack]

The battery had been hooked up to a small solar panel with an output of less than 1 amp; this is designed just to keep the battery topped up when not in use. Also this was the third start of the day, not the first. Finally, about an hour and a half had elapsed since the engine had been switched off. Surlely enough time for the gassing to stop?

 

[CalicoJack]

No we were not equalising them. They are independent of each other and the starter battery does nothing, except start the engine.

 

[duncan]

[ QUOTE ]
I went to start, for the third time that day

[/ QUOTE ]
suggests, but not conclusive I accept, that the battery hadn't been gassing away for some time....................

 

[VicS]

Yes hydrogen and oxygen are both released from a battery in just the right proportions to produce maximum impact if there is a little spark in the vicinity. It may have ben due to a poor conection on one of the battery terminals or the stater itself if it is in the same enclosed space as the battery. Never actually heard of it but even an internal battery fault could be the cause.

Your experience underlines how easy it is to ignite the mixture and how serious the result could be. It should promp anyone reading this to check the correct sequence that should be used when connecting jump leads. That can easily cause a spark and as you would be leaning over the battery at the time it could explode in your face!

 

[Csail]

Could you remind us of the correct sequence.

 

[huldah]

The lower the fluid level in the battery, the bigger the explosion.

Philip

 

[pheran]

[ QUOTE ]
Never actually heard of it but even an internal battery fault could be the cause.


[/ QUOTE ]

This happened to me big time. Put the boat back in the water one Spring after a very hard Dutch winter - temperatures down to to -15C. Engines were running, so all batteries being charged but the first time I attempted to use the bowthruster, one of our big 235Ah jobs blew itself apart. Investigation by the experts suggested that the electrolyte had actually frozen at some stage and created a tiny gap between the battery post and the plate. The large current draw of the bow thruster was enough to cause an internal spark, a huge bang and a hell of a mess to clear up!

 

[VicS]

Lucky you were not near it. The thought of one exploding in my face like that sends shivers down my spine. Thanks for confirming that an internal fault can cause it.

 

[William_H]

The correct sequence is that which minimises your proximity to any battery when connecting the last lead. Usually for cars you connect the positivem onto both batteries then the negative to body (or wiring remote from the battery) of both cars or battery terminal of one to body of the other. (last connection) If you go for neg terminals on both batteries then the last connection is made to the battery least likely to explode. (and keep your face as far away as poss.
If it is on a boat then the principle remains to make the last connection remote from either battery. BE CAREFULL
Yes batteries do explode either from an internal fault allowing a spark within the battery ( exploding gas within the battery) or an external spark most likely (one would think) from a battery that has been producing a lot of hydrogen. I had one explode on me long ago. Batteries had been removed from cars to run lighting. I think long after they were charged. I don't know if I shorted wires but one just blew the side out. Fortunately no injuries but very frightening. olewill

 

[VicS]

[ QUOTE ]
then the last connection is made to the battery least likely to explode

[/ QUOTE ] The last connection should definitely be made away from either of the batteries. With cars that usually does mean to a bit of the engine. Its the last connection, obviously, that can spark as it is made so if that is made well away from the batteries then it practically eliminates the explosion risk, at least from that source. It may be more dificult on boats where the batteries are hopefully in their own ventilated locker rather than in the engine compartment
[ QUOTE ]
keep your face as far away as poss

[/ QUOTE ] The furthest you can get your face away is only one arms length and since you have got to be able to see what you are doing you will be facing it.

 

[stephenmartin]

as an aside...I have a solenoid that connects the domestic to the starter battery if i ever drain the starter for any reason.....

One engine charges the starter battery and the other charges the domestics...no need to worry about charging diodes...nice and simple

With one engine the solenoid could be energised to charge both batteries during engine running