Electric vehicles in underground parking

CelticRambler

An interview with one of the rescue coordinators in Miami the other day raised an interesting point: he remarked that a significant complication in the rescue effort ("something we saw for the first time in 9/11, but it's much more common now") is the presence of electric vehicles in the underground carpark. The building collapsing on top of a giant lithium battery which is then doused in water (fire control or torrential rain) is being implicated in at least one of the fires that are currently burning on the site.

Given the increasing number of flooding events affecting the affluent towns and cities where electric vehicles are most popular, and where underground parking is frequently used to get cars off the streets, will this risk of making a bad situation worse encourage local authorities and/or owners of apartment blocks to ban electric vehicles from underground spaces, in the same way that LPG-powered vehicles are frequently banned from using tunnels?

markpb

CelticRambler wrote: »

The building collapsing on top of a giant lithium battery which is then doused in water (fire control or torrential rain) is being implicated in at least one of the fires that are currently burning on the site.

Aren’t all car fires, including EVs, extinguished by dousing them in water?

athlone573

markpb wrote: »

Aren’t all car fires, including EVs, extinguished by dousing them in water?

Point being that lithium (at least in its raw state) reacts badly to water


There are different types of extinguisher (co2 gas, foam, water) can be used for small fires

markpb

Here’s Tesla’s advice from their Emergency Response Guide

If the high voltage battery catches fire, is exposed to high heat, or is bent, twisted, cracked, or breached in any way, use large amounts of water to cool the battery. DO NOT extinguish with a small amount of water. Always establish or request an additional water supply.

Battery fires can take up to 24 hours to extinguish. Consider allowing the battery to burn while protecting exposures.

It definitely sounds like something that could complicate a response to a building collapse but given how rarely they happen, it doesn’t seem like a reason to ban them.

CelticRambler

markpb wrote: »

Aren’t all car fires, including EVs, extinguished by dousing them in water?

athlone573 wrote: »

Point being that lithium (at least in its raw state) reacts badly to water


There are different types of extinguisher (co2 gas, foam, water) can be used for small fires

If I understood the rescue coordinator's concern, it was that there is no proper access to the source of the fire - it's just "somewhere in there" and there's no way to direct any extinguishing medium towards the fire in a concentrated, effective way (the rubble will divert it all over the place)

markpb wrote: »

It definitely sounds like something that could complicate a response to a building collapse but given how rarely they happen, it doesn’t seem like a reason to ban them.

LPG-powered vehicles probably crash less frequently these days than underground parking facilities are flooded, so if a risk-analysis deems them to be worth banning from enclosed spaces, then the same logic should identify an "unacceptable level" of risk from potential EV damage, especially in zones already at risk from environmental/geological factors (earthquakes, sinkholes, flooding, reclaimed land ... )

eclipsechaser

The local authorities should probably just focus on not having their buildings collapse.

Would e-cars go on fire from a regular flood (without a building collapse)?

CelticRambler

eclipsechaser wrote: »

The local authorities should probably just focus on not having their buildings collapse.

That's a bit like saying people should just drive more safely and we wouldn't need to wear seat belts ... :rolleyes:

eclipsechaser wrote: »

Would e-cars go on fire from a regular flood (without a building collapse)?

This is something that remains to be seen. For the moment, most EV owners are (probably) the kind of driver who'll take care of their vehicle, so there's (probably) little risk that there's avoidable, unseen damage to the battery or it's connections. As they become more common, though, chances are you'll have more people picking up "bargain" vehicles that do have an un-repaired vulnerabilities. Then you're into the wrong place/wrong time scenario. The problem might be exaggerated if the vehicle is being charged at the time.

In fact, I would imagine that it'd only take half a dozen such vehicles to burst into flames on someone's flooded driveway for insurance companies to say they won't cover any EV-related fire and associated damage in enclosed spaces.

Possibly as significant a (de)motivation would be the effect on public opinion if rescue efforts, such as that going on in Miami, are delayed because of a lithium battery fire and victims are pulled out dead two, three or four days later. It won't matter if they were probably already dead - a single lawsuit by an aggrieved relative would change the landscape quite quickly.

krissovo

EV’s and high power components are rated to IP66, you could blast a EV battery all day with a high pressure hose and it will not go bang. To survive a flood you only need IP65 which is low pressure ingress so there is little chance water from a flood getting into the components.

A damaged battery maybe a different story but I have seen videos of new cells getting punctured by steel bolts in water (fully charged show) and barely a slight fizzle.

I always like the early leaf video of fording water.
https://youtu.be/Y9plRzRZ_PY

eclipsechaser

CelticRambler wrote: »

That's a bit like saying people should just drive more safely and we wouldn't need to wear seat belts ... :rolleyes:

Not really. Accidents will always happen on the roads because of the complexity of millions of humans interacting with each other.

But if you've got good oversight and enforcement from local authorities, a collapse like Miami should never, ever happen. That's what I'd be focusing on if I were the local authority.

It would be like saying we should ban ships going under bridges because the bridge might collapse and people on the bridge might hit the boat. Maybe we should just ensure that bridges are well maintained instead.

innrain

I'm sorry but it is not clear to me what is the question. Ev in the event of flooding or fire?
Or both?

electricus

Li Ion batteries don’t contain any pure lithium metal so exposure to water should not be an issue and the water should extinguish any fire.

Lithium metal fires are class D, don’t use water!!

https://www.extinguisheradvice.org.uk/types-of-fire-extinguisher.php

bambam

Official instructions from Tesla are to use a LOT of water, we're talking up to 8000 Gallons / 30,000 litres !!

See
https://www.documentcloud.org/documents/20889394-2016_model_s_emergency_response_guide_en#document/p25/a2040184


https://www.nbcnews.com/business/autos/federal-regulators-warn-risks-firefighters-electrical-vehicle-fires-n1271084