6 ms·

This article is not about if EVs are safe. It's about the fact that putting out a fire when batteries are involved is hard. Every week there is a fire on a car

This article is not about if EVs are safe. It's about the fact that putting out a fire when batteries are involved is hard. Every week there is a fire on a cargo ship. Most are not caused by the cargo. But when the cargo catches fire you want to be able to put it out before the whole ships turns into scrap.

mlindner 4y ago
EVs catch fire drastically less than combustion fueled vehicles because they don't involve explosive materials. Also we ship giant ships full of oil and gas all over the world every single day which is vastly more combustible than batteries.
- kec 4y ago
  ICE vehicles aren't filled with fuel when shipped, and oil and gas both have to aerosolize in an oxygen rich environment before ignition is possible. Batteries just have to get hot, and that can occur from simple mechanical damage.
  - KennyBlanken 4y ago
    ICE vehicles contain enough gas to be driven around at the plant lots, in/out of autocars (rail cars that carry cars), around at port lots, on and off ships, and so on. "Simple mechanical damage" to the battery in an EV is a lot harder than you think. The packs are designed to remain intact in crashes...
- IshKebab 4y ago
  Oil and gas require oxygen to burn.
  - Ekaros 4y ago
    And heat. And you know what is around ships? Near infinite amount of easily handled high heat capacity coolant. Okay, usually the stuff is pretty contaminated, but some cleaning and resurfacing is better than everything staying burning.
- Ekaros 4y ago
  Maybe we should demand same safety standards from EVs. Fill those parts that could cause fire with inert gas if that helps. Yearly or as often checks that these systems operate correctly.
- krisoft 4y ago
  > Also we ship giant ships full of oil and gas all over the world every single day which is vastly more combustible than batteries. I see what you are saying, but the way we mitigate the fire and explosion hazards on oil and gas transport ships is not really applicable to roll-on/roll-off ships. The oil tankers and LNG ships use a technic called innert atmosphere to protect their cargo from fire hazard. The idea is that they fill the ulage spaces with a gas low in oxygen to make sure an explosive mixture can’t form. It would be very hard to innert the whole cargo space of a RO/RO ship the same way, might damage the cargo, would be hazardous to the operators and wouldn’t actually help with a potential thermal runaway of a battery anyway. I will discuss these points in detail: How do they generate this innerting gas usually? There are two main options. You either use nitrogen, or you pipe in the exhaust gas of the engines. Nitrogen would probably be cost prohibitive. The RO/RO ships are cavernous. The exhaust gas based sytem would cost less, but would damage the cargo. Nobody would want a car which reeks like an ashtray. The innerted atmosphere is obviously incompatible with human occupancy, yet the cars are usually driven on and off these carriers by a small army of operators. So you need to have processes to vent the innert atmosphere before the vehicles can be embarked/dissembarked, and you need other processes to ensure the venting worked properly otherwise your shore crew will suffocate. This adds complexity, and risks to the operation. This is not a problem on tankers because there nobody needs to enter the tanks during normal operations. And then finaly why it might not help after all? The nature of electric vehicle battery thermal runaway is such that it doesn’t require oxygen from the atmosphere. It is an exotermic reaction, but not a “fire” in the fire-triangle sense. So all in all, the one big trick of the tankers can’t be used with vehicle carrying operations. Thus the analogy is less than useful. Not saying that we can’t carry EVs safely, just that our ability to carry fuels safely does not in any way correlate with our ability to carry EVs safely.
  - _ph_ 4y ago
    The problem is, that a lack of oxygene might prevent fires, but not battery shorts and the consequential heat. For treating battery fires, water is the best. Fortunately, water is easy to come by for a ship. So one component to transition car carriers is to add large sprinkler systems, which can quickly cool down a car with a thermal runaway. Ironically, what is often claimed as a fundamental problem with batteries, their lower energy density than fuel, should make them less dangerous in the case of a disaster in the case of a fire. But the nature of the fire is differently and needs to be handled accordingly. (Of course, shipped cars probably only contain a minimum amount of fuel, but likewise, electric cars would only be minimally charged)
audunw 4y ago
Why is it hard to put out a fire when EV batteries are involved? If the fire doesn't start in the EV battery why would the battery catch fire? It might sound like an odd question, but we have experience with this in Norway, and the results are counterintuitive. Cars in a large airport parking garage caught fire, and it had many EVs in it. Not a single battery pack caught fire. Only the interior of the EVs did. If they were all EVs the fire would likely be less severe, or not have started at all (an ICE car started it) Battery packs are very well insulated against fires. Assuming the fire doesn't go completely out of control, I don't see a reason to worry much about battery packs catching fire.
- blenderdt 4y ago
  If the battery catches fire they are very hard to out out. But you are right that it's maybe harder to set the battery on fire in the first place.
  - hollander 4y ago
    It may be harder, but it will happen sometime in the future.
- elihu 4y ago
  One of the problems is that lithium ion batteries can't be discharged fully without destroying them. Effectively, the batteries are a very large energy source that can never be fully turned off. Another problem is that (if I understand correctly) lithium ion battery fires tend to produce their own oxygen. Another problem is that a manufacturing defect in one cell could cause the whole pack to catch on fire. According to the article, a fourth problem is that roll-on/roll-off car carriers just store a bunch of cars in one big space, and there aren't barriers to prevent one car from starting all its neighbors on fire. Putting out an EV battery fire basically entails dumping enormous amounts of water on it to keep the temperature under control until it's cool enough that it doesn't auto-ignite as soon as you stop. That can take hours. I tend to agree that the risk of EV fires is overblown. ICE cars catch on fire all the time and we don't usually hear about it because it's not all that rare or unusual. It just doesn't make the news. EV fires are a novelty so we hear about them. (Not that any amount of vehicle fires is okay.) I do think though that if you're moving thousands of cars together on a ship, then that's maybe creating a different kind of risk profile. I look forward to wider adoption of LFP batteries. They aren't immune to fire; I think the electrolyte is still flammable. They just aren't nearly as energetic when they burn, and they're harder to ignite in the first place.
throw93232 4y ago
EVs are safe if you remove batteries. If batteries can not be easily removed and serviced, it is unsafe design. We need basic regulations around safety here.
- jbay808 4y ago
  I'm all for serviceable batteries, but I don't see how it solves the shipping safety issue. So you ship the EVs without batteries, and then... you ship the batteries?
  - hutzlibu 4y ago
    I think that might be done at some point. So most shipments of cars are hazard free and cheap (to insure). And then you have high risk battery shipments. With lots of expensive measures to minimize risks and fail safe. (This is already today a thing, as you can ship items without batteries for less money.)
    - _ph_ 4y ago
      It is not clear to me, why it would be cheaper to ship the batteries separately. The car shipment might be theoretically cheaper, however it is much more difficult to ship cars which cannot drive. On the other side, you would have the increased risk for the battery shipment with the associated insurance costs. However, it is not obvious to me, that shipping electric cars is more risky. Actually all statistics point to electric cars being more safe than combustion engined cars. As the article points out, it is probably necessary to change best practises of handling electric vs. combustion engined cars. Making really sure, that no car moves and crashes into others, change in firefighting strategies. Make sure, that the cars only contain a minimum amount of charge and of course continue to improve battery safety itself.
      - FabHK 4y ago
        And you would not want to place the batteries densely together, in case of fire. Maybe put a few of them in some metal container or so, to keep them apart. Then one could put wheels on that container to move them more easily, maybe even add an engine.

mlindner 4y ago

EVs catch fire drastically less than combustion fueled vehicles because they don't involve explosive materials. Also we ship giant ships full of oil and gas all over the world every single day which is vastly more combustible than batteries.

kec 4y ago
ICE vehicles aren't filled with fuel when shipped, and oil and gas both have to aerosolize in an oxygen rich environment before ignition is possible. Batteries just have to get hot, and that can occur from simple mechanical damage.
- KennyBlanken 4y ago
  ICE vehicles contain enough gas to be driven around at the plant lots, in/out of autocars (rail cars that carry cars), around at port lots, on and off ships, and so on. "Simple mechanical damage" to the battery in an EV is a lot harder than you think. The packs are designed to remain intact in crashes...
IshKebab 4y ago
Oil and gas require oxygen to burn.
- Ekaros 4y ago
  And heat. And you know what is around ships? Near infinite amount of easily handled high heat capacity coolant. Okay, usually the stuff is pretty contaminated, but some cleaning and resurfacing is better than everything staying burning.
Ekaros 4y ago
Maybe we should demand same safety standards from EVs. Fill those parts that could cause fire with inert gas if that helps. Yearly or as often checks that these systems operate correctly.
krisoft 4y ago
> Also we ship giant ships full of oil and gas all over the world every single day which is vastly more combustible than batteries. I see what you are saying, but the way we mitigate the fire and explosion hazards on oil and gas transport ships is not really applicable to roll-on/roll-off ships. The oil tankers and LNG ships use a technic called innert atmosphere to protect their cargo from fire hazard. The idea is that they fill the ulage spaces with a gas low in oxygen to make sure an explosive mixture can’t form. It would be very hard to innert the whole cargo space of a RO/RO ship the same way, might damage the cargo, would be hazardous to the operators and wouldn’t actually help with a potential thermal runaway of a battery anyway. I will discuss these points in detail: How do they generate this innerting gas usually? There are two main options. You either use nitrogen, or you pipe in the exhaust gas of the engines. Nitrogen would probably be cost prohibitive. The RO/RO ships are cavernous. The exhaust gas based sytem would cost less, but would damage the cargo. Nobody would want a car which reeks like an ashtray. The innerted atmosphere is obviously incompatible with human occupancy, yet the cars are usually driven on and off these carriers by a small army of operators. So you need to have processes to vent the innert atmosphere before the vehicles can be embarked/dissembarked, and you need other processes to ensure the venting worked properly otherwise your shore crew will suffocate. This adds complexity, and risks to the operation. This is not a problem on tankers because there nobody needs to enter the tanks during normal operations. And then finaly why it might not help after all? The nature of electric vehicle battery thermal runaway is such that it doesn’t require oxygen from the atmosphere. It is an exotermic reaction, but not a “fire” in the fire-triangle sense. So all in all, the one big trick of the tankers can’t be used with vehicle carrying operations. Thus the analogy is less than useful. Not saying that we can’t carry EVs safely, just that our ability to carry fuels safely does not in any way correlate with our ability to carry EVs safely.
- _ph_ 4y ago
  The problem is, that a lack of oxygene might prevent fires, but not battery shorts and the consequential heat. For treating battery fires, water is the best. Fortunately, water is easy to come by for a ship. So one component to transition car carriers is to add large sprinkler systems, which can quickly cool down a car with a thermal runaway. Ironically, what is often claimed as a fundamental problem with batteries, their lower energy density than fuel, should make them less dangerous in the case of a disaster in the case of a fire. But the nature of the fire is differently and needs to be handled accordingly. (Of course, shipped cars probably only contain a minimum amount of fuel, but likewise, electric cars would only be minimally charged)

audunw 4y ago

Why is it hard to put out a fire when EV batteries are involved? If the fire doesn't start in the EV battery why would the battery catch fire? It might sound like an odd question, but we have experience with this in Norway, and the results are counterintuitive. Cars in a large airport parking garage caught fire, and it had many EVs in it. Not a single battery pack caught fire. Only the interior of the EVs did. If they were all EVs the fire would likely be less severe, or not have started at all (an ICE car started it) Battery packs are very well insulated against fires. Assuming the fire doesn't go completely out of control, I don't see a reason to worry much about battery packs catching fire.

blenderdt 4y ago
If the battery catches fire they are very hard to out out. But you are right that it's maybe harder to set the battery on fire in the first place.
- hollander 4y ago
  It may be harder, but it will happen sometime in the future.
elihu 4y ago
One of the problems is that lithium ion batteries can't be discharged fully without destroying them. Effectively, the batteries are a very large energy source that can never be fully turned off. Another problem is that (if I understand correctly) lithium ion battery fires tend to produce their own oxygen. Another problem is that a manufacturing defect in one cell could cause the whole pack to catch on fire. According to the article, a fourth problem is that roll-on/roll-off car carriers just store a bunch of cars in one big space, and there aren't barriers to prevent one car from starting all its neighbors on fire. Putting out an EV battery fire basically entails dumping enormous amounts of water on it to keep the temperature under control until it's cool enough that it doesn't auto-ignite as soon as you stop. That can take hours. I tend to agree that the risk of EV fires is overblown. ICE cars catch on fire all the time and we don't usually hear about it because it's not all that rare or unusual. It just doesn't make the news. EV fires are a novelty so we hear about them. (Not that any amount of vehicle fires is okay.) I do think though that if you're moving thousands of cars together on a ship, then that's maybe creating a different kind of risk profile. I look forward to wider adoption of LFP batteries. They aren't immune to fire; I think the electrolyte is still flammable. They just aren't nearly as energetic when they burn, and they're harder to ignite in the first place.

throw93232 4y ago

EVs are safe if you remove batteries. If batteries can not be easily removed and serviced, it is unsafe design. We need basic regulations around safety here.

jbay808 4y ago
I'm all for serviceable batteries, but I don't see how it solves the shipping safety issue. So you ship the EVs without batteries, and then... you ship the batteries?
- hutzlibu 4y ago
  I think that might be done at some point. So most shipments of cars are hazard free and cheap (to insure). And then you have high risk battery shipments. With lots of expensive measures to minimize risks and fail safe. (This is already today a thing, as you can ship items without batteries for less money.)
  - _ph_ 4y ago
    It is not clear to me, why it would be cheaper to ship the batteries separately. The car shipment might be theoretically cheaper, however it is much more difficult to ship cars which cannot drive. On the other side, you would have the increased risk for the battery shipment with the associated insurance costs. However, it is not obvious to me, that shipping electric cars is more risky. Actually all statistics point to electric cars being more safe than combustion engined cars. As the article points out, it is probably necessary to change best practises of handling electric vs. combustion engined cars. Making really sure, that no car moves and crashes into others, change in firefighting strategies. Make sure, that the cars only contain a minimum amount of charge and of course continue to improve battery safety itself.
    - FabHK 4y ago
      And you would not want to place the batteries densely together, in case of fire. Maybe put a few of them in some metal container or so, to keep them apart. Then one could put wheels on that container to move them more easily, maybe even add an engine.