Flood Fire Risk With EVs — At Least Some EV Packs Need Better Water Sealing

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In the wake of the recent hurricane that swept Florida and then went and wrecked lower Appalachia, I came across an interesting social media post from local government officials in Pinellas County, Florida. In it, we see the uncomfortable and dangerous death of a Tesla:

Electric Vehicles that have been flooded in saltwater can catch fire. If you evacuated and left an electric vehicle or golf cart in your garage or under a building and you are not able to get to it or move it, we want you to let us know. /1 pic.twitter.com/dpfiXRAGuR

— Pinellas County (@PinellasGov) September 28, 2024

When salt water got inside the Tesla’s garage, it flooded the vehicle. This didn’t initially cause major problems, as the vehicle’s low-slung battery pack is inside a special compartment that’s meant to keep the water out of it. But, given enough time, the water managed to find its way to the battery cells. Because the water had salt in it, it was conductive. This shorted out the cells, causing a chain reaction of awfulness and fire.

When this happened during Hurricane Ian, I didn’t think it was a legitimate problem. After all, we had been assured by Tesla that the battery packs are waterproof. Elon Musk even said that they could serve as a boat in a pinch. We’ve seen lots and lots of videos where Teslas and other EVs ford deep water and get through when other vehicles stall out and flood. So, it didn’t make sense that water would get inside of the pack, and we thought that Florida officials were lying.

But, it turns out that they weren’t, and it turns out that it keeps happening. Given enough time, a Tesla (and possibly some other EV brands) will embrace that “salt life” and then end up in salt death.

What’s not clear is whether this is an industry-wide issue or something limited to certain makes/models. All of the modern EV era media reports I could find mentioned a Tesla vehicle, and sometimes e-bikes and electric scooters. Going further back, some early modern EVs and PHEVs from Fisker and Toyota caught fire after Hurricane Sandy in 2012. We have to keep in mind that Teslas are the most popular EV in the United States today by far and that e-bikes and scooters are even more popular. So, it’s not clear whether these vehicles are more vulnerable than others or if they just come up in reports because of sheer numbers.

All EVs Should Be Waterproof

Here’s the thing: this is unacceptable. Most importantly, lives are put at risk by battery packs that can’t spend a few days flooded without becoming a hot mess. People evacuating should be able to fix up their homes, not come back to a house that first flooded and then burnt. If enough people buy EVs, this could become frighteningly common after a hurricane. This is also terrible for the whole EV industry, as it helps cement the false idea that EVs are generally a bigger fire risk than combustion vehicles, which they are not.

The solution is pretty simple. EV manufacturers need to have some pride in their work and make sure every EV that leaves the factory can handle immersion for long periods without going up in flames. This might require some better sealing where the pack closes up. It’s definitely going to require better check valves that keep pressure from building up inside the pack due to temperature shifts, etc.

This might sound like a ridiculous demand to some, but we have to keep in mind that there are many other products out there that can handle water for long periods. Phones with an IP68 rating are readily available on the market, and there’s no reason that vehicle battery packs can’t be built to a similar standard. I’d propose that an EV should be able to withstand immersion in up to 10 feet of water for a week without water intrusion into the pack.

Featured image: a screenshot from the Pinellas County tweet above (fair use).