Electric car problem

That's odd, because I was thinking the opposite yesterday when this popped up on my Twitter

Moving 1-2 tonnes of metal around at speed requires a lot of energy. The hope is that solid state batteries will be cheaper and safer than lithium, but driving around with a few gallons of flammable liquid on board isnt ideal either.

If it were reversed. How would you feel about the need to store thousands of litres of fuel, probably not too far from you now and not only that, allow 'people' to actually pump that highly flammable liquid themselves?

It similar to how I feel with automated cars, i'd rather all get switched to automation rather than allow the poor things to try and work with humans and anticipate their actions.
 
Well that was just silly!

Why on earth did they spray a potentially electrical fire with water?

If that had been a car with a full tank of petrol in a petrol station I suspect the BOOM! might have been a touch more dramatic than that rather piddly pop.

Ive no idea what these Chinese only EVs are charging at - could be 50-100Kv (15-30x the maximum limit of a domestic socket). It could just have been a faulty charge controller - until it was doused!


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Only thing i can think from top of my head that could explode there like that, would be H2O mixture that comes from electrolysis. Hydrogen burns in oxygen, both are produced if batteries are doused in water. Add a spark from somewhere, and we have explosion.
No water, no gas mixture to explode.
Same thing can happen in regular usage with gas powered cars and gasoline powered cars in hollywood.
Probably happened because chinese quality car let water in wrong places and firefighters were not properly trained.
 
maxufeiss said:
Only thing i can think from top of my head that could explode there like that, would be H2O mixture that comes from electrolysis. Hydrogen burns in oxygen, both are produced if batteries are doused in water. Add a spark from somewhere, and we have explosion.
No water, no gas mixture to explode.
Click to expand...

The lithium used in most high performance rechargable batteries (cars/mobiles/laptops/etc) is highly reactive and will burn in the presence of water. The battery casing on an electric car should be watertight (for obivous reasons), so something was obviously very wrong here! There are also different Li-ion battery chemistries, some of which are more stable than others. Most western car manufacturers have used a nickel-manganese-cobalt composition, which is very stable, even when damaged, but Tesla have used nickel-cobalt-aluminum oxide, which is slightly less stable but offers great performance, leading to the occasional Tesla fire story. There is a greater variation of battery chemisties used in Chinese cars at the moment, so it could be the type of battery it had.
 
My guess is the battery experienced a run away cell that expanded enough to split the battery housing, add the fire hose hundreds of gallons of water the explosion was inevitable. Why did they apply more water after the first "pop", there could have still been intact cells that could also have exploded.
 
This looks clearly more explosive than lithium burning. Lithium would burn much longer too, not stop right after. And you can see burning gas rising upwards after explosion.
 
I like the LiFePO4 chemistry for its sheer abusability and stability but it does lack power density compared to some of these newer cells.

If you fancy an educational lithium battery fire video check out YouTuber Richrebuilds and search ‘Tesla battery fire’. This shows the danger of a poorly designed charger set up with no safety shut off in a single Tesla pack (retrofitted to a Disney princess EV) and a subsequent thermal runaway event.

Now imagine a flood of water hitting that battery mid-burn!


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