There is video out now, that shows the kids survived the accident, but were killed by the fire as people tried to rescue them. Heartbreaking to see as a parent....
There is video out now, that shows the kids survived the accident, but were killed by the fire as people tried to rescue them. Heartbreaking to see as a parent....
There is no such thing as crash proofing, no matter what the vehicle is. If this was any other vehicle, the results would most likely be the same, except we wouldn't be hearing about it except if we lived in the area. The fact that we are dealing with a vehicle that has several different technologies that people are curious about and sometimes scared of makes these accidents national news instead of just local.A tragic business, particularly as it seems from reports that the fire prevented rescuers to reach the victims. I assume that each individual cell is not equipped with short-circuit protection circuitry and a short circuit of the battery due to damage would cause the whole pack to overheat and burn.
At 18 one assumes one is immortal and exploring the limits of your capabilities is natural at that age. Perhaps there is a case for cars to be provided with parental controls to limit the performance? At the very least the batteries should be crash-proofed though.
I believe every cell is fused, but if the integrity of the pack is compromised in a violent enough fashion, then all bets are off. Just like anything with a lot of stored energy.A tragic business, particularly as it seems from reports that the fire prevented rescuers to reach the victims. I assume that each individual cell is not equipped with short-circuit protection circuitry and a short circuit of the battery due to damage would cause the whole pack to overheat and burn.
At 18 one assumes one is immortal and exploring the limits of your capabilities is natural at that age. Perhaps there is a case for cars to be provided with parental controls to limit the performance? At the very least the batteries should be crash-proofed though.
As you said in your original post, you assume that it is not being done in the Tesla, when I believe I saw something that said that they do have something like that. I guess both of us will need to do more research to know for sure. I do know for a fact that no one outside of my area heard about a head on collision that killed both drivers. I came upon the accident shortly before first responders arrived, and there was fire involved in those vehicles. Maybe there could be something to improve those vehicles to keep them from catching on fire. The facts are that people are more interested in hearing about the Tesla accident because of the new technologies that they are curious about and sometimes scared of.Well, it's true you cannot completely crashproof any car, but you can certainly do something to make fire less likely by including short circuit and overcharging logic in each cell. This is a small circular PCB with a few tiny surface mounted components on it which fits inside the cylindrical cell just below the central terminal. This will prevent the cell discharging more than a safe amount of current, shut it down if it overheats, and prevent you overcharging it. Certainly, the 18650 cells I use in my torch (flashlight?) incorporate these.
If the cell receives physical damage that may well cause it to be short circuited and it will overheat even with such protection, but it will be protected from an external short circuit such as insulation being pierced by crushed metal.
There ARE things that can be done to make these cars safer I think.
As you said in your original post, you assume that it is not being done in the Tesla, when I believe I saw something that said that they do have something like that. I guess both of us will need to do more research to know for sure. I do know for a fact that no one outside of my area heard about a head on collision that killed both drivers. I came upon the accident shortly before first responders arrived, and there was fire involved in those vehicles. Maybe there could be something to improve those vehicles to keep them from catching on fire. The facts are that people are more interested in hearing about the Tesla accident because of the new technologies that they are curious about and sometimes scared of.
Sent from my SM-G935V using Inside EVs mobile app
I assume that each individual cell is not equipped with short-circuit protection circuitry and a short circuit of the battery due to damage would cause the whole pack to overheat and burn.
...one might begin to wonder if these cars are rather more prone to fires than ICEs.
Each cell is equipped with a "fusible link". Nonetheless, we've seen two reports of horrific accidents where the battery pack was ripped open in a crash, with cells exploding "like firecrackers", according to onlookers.
Since I'm not an electrical engineer, I won't presume to guess exactly what has caused that to happen, or why the fusible links did not prevent it. I will presume to guess that in such cases, perhaps only a small percentage of the cells explode. With the pack containing thousands of cells, if they all exploded within a few seconds it wouldn't sound like individual firecrackers going off; it would be just a continuous roar.
Fusible links won't protect against heat from adjacent cells burning. I would imagine the temperature rising and the pressure inside a cell going up until it pops. Then it would burn and damage the adjacent cells which would do the same. This takes time and would explain reports of them going off like firecrackers over a period of time.
How thoroughly have these battery packs been tested in crashes I wonder?
Fusible links won't protect against heat from adjacent cells burning. I would imagine the temperature rising and the pressure inside a cell going up until it pops. Then it would burn and damage the adjacent cells which would do the same. This takes time and would explain reports of them going off like firecrackers over a period of time. How long this goes on depends on the geometry of the debris.
How thoroughly have these battery packs been tested in crashes I wonder? It is worth remembering Boeing's answer to battery fires. Put them in a stainless steel box with a chimney!
Well, for the sake of the people who buy these things I hope you're right. However, if they ARE going off like firecrackers with one cell taking the next down as reported it suggests that precautions taken to prevent it are inadequate.