EV fires are a new challenge

[bwilson4web]

Please do not run around with your hair on fire, and jump off a tall building. EV fires present a unique risk as new as their wide spread adoption. I'm a reluctant fan of "StacheD Training," a mechanical engineer with serious fire fighting credentials. So his latest YouTube is sobering:


I had first thought that fire blankets would provide a solution for dealing with EV fires. Not that they put them out but rather, they limit spreading the heat effects. But it turns out the generated gasses are spontaneous combustable. The blanket traps the gas and upon exposure to air, a fire ball envelopes the too curious fire fighter:

The blanket traps the hot, combustable gasses, primarily the electrolyte, and upon exposure to air, a sudden flashover occurs. The bubble of gas under the heat blanket needs to be treated very carefully and several thoughts come to mind:

• pilot pipe - pushed under the blanket with a valve than can be opened to release the combustable gas into a 'burner' like we see at oil refineries.
• center vent hole - same idea but built into the blanet that opens to let the gas release and combust in the center of the blanket.

The combustion of EV battery gasses is a different hazard but shares characteristics with the pound of black powder and my inventory of rifle ammunition. Yes they are dangerous in a fire but we know how to deal with it (i.e., "Run away! Run away!".) Actually, disburse with high pressure water at a distance.

Remember the exploding laptops? Those were poorly designed, early battery management systems. Better designed today, airlines still carry a burn containment bag for cell phones and laptops in the cabin. So the risk can be mitigated for both small and some larger scale EV fires.

Bob Wilson

 

[brianc35]

Even small-ish Lion batteries are not allowed on PASSENGER aircraft. I believe they are eligible for commercial (eg, fed ex) flights.
The fire risk is small, but it's real, and when it does errupt, it's a whole new world of extinguishing them that departments need to train.

There's been a few tesla fires around here over the years on the road, and every time, it's a complete loss/black pavement left. Some wheel remnants sometimes.

The average department can't do much but watch and get people back.

I imagine a new foam will exist some day, but a lot of the old foams are full of pfas's and other forever chemicals that ruin the planet.

 

[electriceddy]

Actually, disburse with high pressure water

This new method seems a lot more effective:

 

[insightman]

This new method seems a lot more effective

After EVs on the Morning Midas (Mourning Midas?) caught fire earlier this month, forcing the crew to evacuate their ship, this article described how EV-carrying ships could use cooled, concentrated, briny seawater to stop fires (but the article doesn't say who gets the job of piercing the EVs' windows to insert the hose that will deliver the cold, briny seawater):

Unlike traditional fire suppression methods – which act from the outside and often fail to extinguish the core fire – the brine system targets the battery directly from inside the vehicle. In the event of a fire, one window is penetrated, and cold, saturated brine is delivered directly into the cabin. This allows the fluid to pool around the battery compartment, rapidly cooling the cells, limiting oxygen exposure, suppressing flammable materials, and even short-circuiting and depowering the battery.

“We believe this system sets a new standard. It’s low-tech in the best way – reliable, proven, and easily maintainable. Most importantly, it addresses the real issue: heat – not just the flames, but the fire inside the battery” said Finn Wollesen, managing director of Knud E. Hansen.

In a full-scale fire test conducted in the Faroe Islands, the system extinguished a fully developed EV fire in under one hour, including response times. In contrast, lithium-ion battery fires often burn for 24 hours or more when left to self-extinguish, and can reignite multiple times.