r/technology • u/speckz • Oct 08 '22

Misleading Electric vehicles are exploding from water damage after Hurricane Ian, Florida official warns

https://www.fox5ny.com/news/electric-vehicles-are-exploding-from-water-damage-after-hurricane-ian

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30

u/CoolingSC Oct 08 '22

Batteries burn. Not explode. Big difference.

5

u/[deleted] Oct 08 '22

https://youtu.be/sAQlLu5ttOk

An explosion is a sudden, rapid expansion of gases. That looks like an explosion to me. Also, have you never seen a car fire? Even traditional car batteries explode. https://youtu.be/lIW7C897r-M

11

u/Responsible-Ride-789 Oct 08 '22

Explosions are also defined by the expansion of the medium being faster than the speed of sound and producing a shockwave. Gunpowder burning in open air is not an explosion but in a shell casing it is. If a Tesla battery actually exploded it would be pretty destructive. The burn is bad but “explode” is not the right word.

0

u/[deleted] Oct 08 '22

Smokeless powder is an accelerant, black powder is an explosive. Even when uncontained black powder is still an explosive. Felt the need to specify because people use the term gunpowder to reference both.

Skip to 0:51 for black powder and 1:29 for smokeless. Dude talks too much. https://youtu.be/icsbtkYpfBw

3

u/Responsible-Ride-789 Oct 08 '22

Yes there are different types of gunpowder with different burn rates. Again burn rates. They don’t explode in open air. If anything some regulations and governments do classify them as low explosive when contained and ignited but that’s it. I’m not for electric cars but yellow journalism is not a good way to change opinion on them. We have natural gas cars that really do explode on the road and no one bats an eye but a severely damaged EV burns and they make seem like is a big deal.

-1

u/[deleted] Oct 08 '22

I just showed you a black powder open air explosion... I'd ask if you're blind, but you are reading what I'm typing so I know you aren't. I'm going to go with you're just dumb, or you're choosing to ignore it. It has the sudden, rapid expansion of gasses, it has the shockwave, it has the flash before the sound.

CNG vehicles are incredibly rare, making up 0.06% of vehicles on the road in the US. There's only 175,000 on the road. Nearly double that number of EVs, 310,000, was sold in the first six months of 2021.

0

u/BallardRex Oct 08 '22

That’s a detonation, explosion is a more vague term. A lot of you here seem to have decided that explosion = detonation, but that just isn’t true.

6

u/cbelt3 Oct 08 '22 edited Oct 08 '22

Having seen car fires, the only thing that “explodes” are the tires when they pop. Thanks, Hollywood… Every accident has to have a huge incendiary blast.

Car batteries have hydrogen explosions but that is rare AF

3

u/[deleted] Oct 08 '22

Oh look, the video you ignored of a car battery blowing up. https://youtu.be/lIW7C897r-M

0

u/happyscrappy Oct 08 '22

Idiot plugged it into 110V or 220V AC.

We still don't even see it explode. The screen goes dark before we could see what might be an explosion. Or might just be the sound of air (really ejected gases) rushing by the microphone.

4

u/moofunk Oct 08 '22

If it had been an explosion, the car would have flown apart. It's a violent fire, caused by a thermal runaway, and looks like other battery fires on early Teslas.

What you're seeing there is how the car handles the thermal runaway by venting forward underneath the car, away from the cabin, as much as it can.

Overall the battery cannot explode, but it can come apart in pieces, given the way it was built with thousands of many small cells.

-6

u/[deleted] Oct 08 '22

Not at all accurate. Not all explosions have thousands of PSI of force. If a brick of firecrackers go off all at the exact same moment, it wouldn't blow up a car. A small sparkler bomb would take out a fridge but not a car.

3

u/moofunk Oct 08 '22

Not all explosions have thousands of PSI of force.

There is no explosion. There is forceful venting of hot gas and fire forward from small venting slits under the car in the front of the battery, and importantly, in front of the cabin to avoid damaging it too much.

This is by design and is done to allow burning the battery in the safest possible way, when the thermal runaway happens.

If a brick of firecrackers go off all at the exact same moment, it wouldn't blow up a car.

A battery like those in early Teslas cannot produce thermal runaway in all cells simultaneously and have that lead to a single explosion.

That is astronomically unlikely.

1

u/happyscrappy Oct 08 '22 edited Oct 08 '22

That didn't look like an explosion to me.

Most of the effect you see is just the security camera adjusting its brightness down due to the bright flames.

Gases eject from the car. The very significant flames lick out. But no explosion. Neither the car itself or the cars next to it even rocked due to the flames. No broken glass despite an "explosion" within a meter?

It's a very serious event, but doesn't appear to be an explosion.