REALLY hot battery, what would you do/have done?

[lw395]

Nigel Calder says they do and to keep an axe on board for emergency cable cutting. He describes it as a process by which the raised temperature allows the battery to accept more and more charge, thereby increasing the batteries' ability to accept charge and so on in a vicious cycle of ever increasing battery temperature until it ruptures. I trust Nigel's opinion.

I think he's right about this.
Not sure about the axe, I have bolt croppers for the rigging though.

There is a lot of energy stored in a charge battery.
If that energy stored as charge turns to heat in a quick uncontrolled way, when the battery is already overheating, I feel that is a reasonable cause to worry.
I raised this thread as a tea-break topic with some electronics guys, one idea was that it might be a good idea to remove some of the energy by discharging the battery, but not too quickly....
I.e. not a heavy load like a starter motor!

Prevention is better than cure, so we should be grateful to the OP for raising awareness.

 

[Otter]

Yes I agree, these stories are useful and make me think through what we'd do.

I did like the irony that the situation was so dangerous SWMBO was sent to the other side of the marina but he could go close enough to undo the covers of the red hot battery very brave or very foolish he has reminded me to check the levels on ours this autumn.

 

[Plevier]

Nigel Calder says they do and to keep an axe on board for emergency cable cutting. He describes it as a process by which the raised temperature allows the battery to accept more and more charge, thereby increasing the batteries' ability to accept charge and so on in a vicious cycle of ever increasing battery temperature until it ruptures. I trust Nigel's opinion.

That sort of thermal runaway can occur but it will stop when the charger is switched off.
Lead acid batteries do not go into any kind of chemical based runaway without charge current present.
I'm horrified at the thought of cutting a battery cable with an axe.
The last thing you want in these circumstances is a spark.
If you can't switch the charger off disconnect it remotely at the mains well away from the battery area.

 

[huldah]

In this case the problem was in the battery, however, it is important to keep batteries topped up, to reduce the capacity to hold explosive gas.