Boat Fire and Sinking in Route du Rhum

[s/v Jedi]

Originally Posted by team karst

is this relevant? I'm not a chemist, and didn't do well at it.

In what way and in what form does lithium react with water?

Lithium reacts intensely with water, forming lithium hydroxide and highly flammable hydrogen. The colourless solution is highly alkalic. The exothermal reactions lasts longer than the reaction of sodium and water, which is directly below lithium in the periodic chart.

2 Li(s) + 2 H2O -> 2 LiOH (aq) + H2(g)

At 750oC lithium reacts with hydrogen to lithium hydride (LiH). The white powder that forms releases hydrogen gas upon later reaction with water, in amounts of 2800 liter per kilogram hydride. As such, lithium can be applied as hydrogen storage.

I passed the exams and that’s all I want to remember… well, the little explosions, burning magnesium etc. were memorable as well

The thing here is that for marine lifepo4 batteries, hermetically sealed cells are used and often those are placed in hermetically sealed housings. There is no water mixing with lithium, let alone at 750 degrees Celsius.

[donradcliffe]

Originally Posted by s/v Jedi

Just the fact that the skipper claims his ballast, being seawater, exploded, shows the sheer display of ignorance.

Its not ignorance, its just a bad translation of the skipper's statement in French.

[CaptainRivet]

Originally Posted by donradcliffe

Its not ignorance, its just a bad translation of the skipper's statement in French.

Let’s agree it’s a series of events happened over several days. Bank and electric gets shorted and he just continues sailing…-I see multiple big mistakes made and he can actually be lucky to be alive doesn‘t matter which battery chemistry was installed.

[goboatingnow]

One would postulate that the seawater shorted the batteries and thd bms dyfbt do the hobbit was supposed to do

Nothing in LFp would suggest this explosion etc has anything to do with LFp

[team karst]

Originally Posted by s/v Jedi

I passed the exams and that’s all I want to remember… well, the little explosions, burning magnesium etc. were memorable as well



The thing here is that for marine lifepo4 batteries, hermetically sealed cells are used and often those are placed in hermetically sealed housings. There is no water mixing with lithium, let alone at 750 degrees Celsius.

Post 64 is my theory of destruction.

[s/v Jedi]

Originally Posted by team karst

Post 64 is my theory of destruction.

Oh my, which page would that be?

Found it, I think there’s a flaw in your theory: the seawater isn’t getting at the BMS nor the electrolyte, because as soon as the BMS switches the battery off, the corroding at the terminals will stop.

Except of course with a battery like mine, which has all cell terminals exposed to water if water makes it gets there.

I did have a similar situation with FLA batteries once and yes one developed a leak around one of the terminals. I suspect some water got into the battery but I never noticed any negative effects. I fixed the leak with some JB-Weld.

[team karst]

Originally Posted by s/v Jedi

Oh my, which page would that be?

Found it, I think there’s a flaw in your theory: the seawater isn’t getting at the BMS nor the electrolyte, because as soon as the BMS switches the battery off, the corroding at the terminals will stop.

Except of course with a battery like mine, which has all cell terminals exposed to water if water makes it gets there.

I did have a similar situation with FLA batteries once and yes one developed a leak around one of the terminals. I suspect some water got into the battery but I never noticed any negative effects. I fixed the leak with some JB-Weld.

I am supposing when submerged, the electrolysis current is quite nominal. Nothing that would alert the BMS to shut down the battery.
Surely, someone out there has some batteries to experiment with. I can supply the seawater, el monitor equipment and photo team. [emoji106]

[s/v Jedi]

Originally Posted by team karst

I am supposing when submerged, the electrolysis current is quite nominal. Nothing that would alert the BMS to shut down the battery.
Surely, someone out there has some batteries to experiment with. I can supply the seawater, el monitor equipment and photo team. [emoji106]

In seawater I would expect it to short out the battery terminals.

[s/v Jedi]

So one of my secret undercover informants send me this info about fires in cars. It appears that EV’s experience fires: 25 fires for every 100.000 EV’s sold.

However, there’s also fires in gas powered cars: 1,530 fires for every 100,000 gas powered cars sold.

This means that even with the dangerous cobalt based lithium batteries, it’s 61 times as safe compared to gas powered

Originally Posted by s/v Jedi

Just the fact that the skipper claims his ballast, being seawater, exploded, shows the sheer display of ignorance.

Just like seawater is not explosive in sailboat environments, neither is a marine lifepo4 battery. A LA battery can explode, because they make hydrogen gas during charging. As they also contain acid, which is exploded around a wide perimeter during such catastrophe, they are a very dangerous thing to have aboard, only topped by propane bottles and gasoline jugs.

Yet we don’t talk about the dangerous LA batteries. We talk about the safe lifepo4 batteries because those who don’t want them for unexplained reasons (probably no money or being Luddite etc.) feel like they need to fabricate reasoning that supports not having them. It’s too hard to live with the feeling of missing out I guess

It also seems that some people ignore the experiments from ABYC which show exactly how safe they are, as well as dozens of videos showing everything including shooting them, spearing them etc. without any consequence.

[HeywoodJ]

Originally Posted by s/v Jedi

...This means that even with the dangerous cobalt based lithium batteries, it’s 61 times as safe compared to gas powered

That's the problem with bulk statistics, they are bulk statistics. The vast majority of electric cars on the road are new. The average EV age in the US is 3.8 years old, and the average car overall is 12.2 years old. 40 years ago there were 3.5x as many car fires per 100,000, with a steady decline to today's numbers, a strong indication that care fires have been reduced significantly over time.

You could only get a meaningful number if you compared cars of the same age. The same study says >70% of car fires occur in cars >10 years old.

What does that mean in the end? 61x is probably a stretch, 15x or 20x is probably a more realistic value

As an example, Tesla only claims 10x - one fire per 200 million miles vs. one per 19 million overall.

[donradcliffe]

Originally Posted by s/v Jedi

In seawater I would expect it to short out the battery terminals.

I was wondering what would happen too, and came across this video

https://www.youtube.com/watch?v=ODbgKXFED5o

Higher voltage and AC, but the thing that hits home is how hot the electrode gets. Plenty of potential for a fire.

[team karst]

Any idea what those bubbles are?

[donradcliffe]

Lots of good stuff going on. My guess is the bubbles are mostly subcooled boiling off the hot electrode. If it was DC, they would be mostly oxygen and hydrogen. The sparks are bits of iron from the electrode. Note that the bulb gets dimmer as he raises the electrode out of the water--less total current, but more concentrated at the tip of the electrode, like welding.

I agree that when the first half a teaspoon of water hits the BMS its game over. It will affect the control circuitry as much as it affects the mosfets, so anything can happen.

As far as I know, even the "sealed" drop in batteries have vent holes where water can get in.

[wholybee]

Originally Posted by donradcliffe

Lots of good stuff going on. My guess is the bubbles are mostly subcooled boiling off the hot electrode. If it was DC, they would be mostly oxygen and hydrogen. The sparks are bits of iron from the electrode. Note that the bulb gets dimmer as he raises the electrode out of the water--less total current, but more concentrated at the tip of the electrode, like welding.

I agree that when the first half a teaspoon of water hits the BMS its game over. It will affect the control circuitry as much as it affects the mosfets, so anything can happen.

As far as I know, even the "sealed" drop in batteries have vent holes where water can get in.

And Lead Acid batteries will also heat, spark, and vent hydrogen. There are lots of things that could have started the fire, but almost none of them are related to the LFP battery chemistry.

The only real fact is, we don't have enough information to guess what happened. Nor do we have evidence that the battery being LFP was a factor.

[JPA Cate]

I agree about the mis-translation of what the skipper said. I'd imagine he used the equivalent of "burst into the salon", or said "exploded all over", trying to indicate the suddenness of the event. Not meaning that actual water exploded, at all.

Ann