And in one of the comments, I see someone talking about using ground effect to gain speed faster.
Maybe good for Hurricanes or Spitfires scrambling in the Battle of Britain.
Less sensible for a commercial cargo aircraft, or I'd guess even a C-47.
Electric Planes
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And in one of the comments, I see someone talking about using ground effect to gain speed faster.
Maybe good for Hurricanes or Spitfires scrambling in the Battle of Britain.
Less sensible for a commercial cargo aircraft, or I'd guess even a C-47.
smartcooky
Penultimate Amazing
Yeah. Whipping the gear up at 10ft above the runway to reduce drag so that your grossly overloaded cargo 727 can begin to climb is not exactly good aviation practice!
theprestige
Penultimate Amazing
Counterpoint: People do what they must, when the reward or the need outweighs the risk.
Look at naval aviation. Nothing about carrier flight operations is good aviation practice! It's inefficient, it's unhealthy, and it's extremely high risk. The only reason (some) navies bother with it, and bother trying to do it well, is because the perceived need for it far outweighs the obvious extreme problems with it.
If someone, somewhere, is paying good money to overload a cargo plane and go all-out on takeoff, then good aviation practice may just be to take the money, overload the plane, and go all-out on takeoff.
I'm saying that batteries are likely to improve and be more safe in the future. I was not suggesting we adopt poorer standards.
theprestige
Penultimate Amazing
Another reason analogies suck ass.
You could have just said you think battery safety is likely to improve.
MRC_Hans
Penultimate Amazing
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In all this, we need to remember that there are other solutions. Batteries are currently the most well developed solution for energy storage, but as we all seem to agree, they also have limitations. There are other solutions in the offing, for various applications. For aircraft, there are various fuels that can be synthesized from electricity, for example hydrogen and ammonia. These could be used directly in properly adapted ICE.
Hans
Hans
Those figures don't make sense to me. Is that over the lifetime of the car? Your source lists them as fires/100,000 cars/sale, which seems like it, I guess. That should skew the numbers lower for younger cars and higher for older cars (that have had a longer time period in which to have a fire).
I think something like fires/100,000 cars/year would make more sense as a metric.
I think your general point is correct, I'm just having a hard time interpreting these particular figures.
That other technologies have tended to have improvements in safety over time is evidence for the proposition that batteries will follow a similar trend.
smartcooky
Penultimate Amazing
Take that up with the source. I would think insurance companies are going want accurate information regarding the way they base their rates and cover?
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Roger Ramjets
Philosopher
Yep. The argument is that EV fires are only lower because there are no old EVs. This may have some merit, but not enough to skew the figures anywhere near that much.
EVs have been sold in quantities large enough to get accurate statistics since 2011 when Nissan introduced the Leaf. The Leaf battery had no thermal management and used lithium-polymer 'pouch' cells that don't have a hard metal case around each cell to contain any flames. If Leaf batteries were catching fire regularly we would have heard about it well before now (any more than a few incidences would trigger a recall). There are a lot of 8-12 year old Leafs around now, which are a similar age to the average gas car (8.4 years in the UK).
Gas cars tend to 'age' faster than EVs, due to vibration and heat. Ford recently had to recall almost a million relatively new vehicles after it was found that wiring was chaffing and causing electrical shorts.
Even the fuel itself can be a cause of fires. Years ago New Zealand started mixing locally produced 'synfuel' in with the petrol, and this had a devastating effect on vehicles whose fuel hoses couldn't handle it. My own car suffered a broken hose that poured petrol all over the engine. Luckily the engine stopped before it could catch fire (not the last time that I would be incredibly lucky with automobiles).
Biofuels can have a similar effect,
Car firms warn of biofuel fire risk
Compared to gas cars, EV batteries have a lot more safety features. The battery management system (BMS) monitors temperature and keeps the cells at an even voltage. Any cell voltage going too high or low will trigger an alarm and prevent the battery from being charged or used. The battery is connected to the vehicle electrics via a contactor that disconnects when the vehicle is off or if anything goes wrong. There are no tubes and hoses etc. feeding highly flammable fuel into the engine bay where it can leak out and ignite hours after the vehicle has been turned off or when next started.
If a lithium-ion battery is damaged it may short out and catch fire due to the heat produced. However this only happens when the battery is severely damaged, not due to going over bump in the road like some people claim. The lithium-Iron-phosphate batteries used in many newer cars are much safer - almost impossible to ignite by puncturing and having a much higher 'cook-off' temperature.
Modern EVs are less likely to catch fire because they are made safer, not just because they are 'new'. I don't have any statistics to prove it, but from my own experience with lipo batteries they don't get less safe as they age. It's actually more likely for a defective battery to short out when new (I have seen a few that did that, none caught fire). If the battery gets past the 'burn-in' period it's generally set for life.
I have seen and heard of a few lithium battery fires. In all cases they were caused by severe damage and/or incorrect charging. We use high power lithium-polymer batteries in our model airplanes. To save as much weight as possible they don't have a BMS or hard case. Our chargers are programmable to suit different battery voltages, sizes, and types. While the charger attempts to identify the battery type by voltage, using wrong settings can cause it to overcharge the battery. Sensible users check the settings twice and and put the battery in a firesafe bag just in case. Despite the theoretical danger, millions of people are doing this without incident.
Of course lithium-polymer batteries are used by billions of people every day in cell phones, laptops, and other electronic devices too, and incidents are extremely rare. Just imagine if all those things were powered by gas engines!
The figures are quite clear. It's only hard to 'interpret' them if you are in denial.
Problem is many Luddites are on a witch-hunt against EVs (and any other 'green' technology) which is making the public hyper-sensitive to their supposed dangers. A gas car model that tends to burst into flames due to a design fault is (rightly) blamed on the manufactuer. An EV model with the same defect is "Because it's an EV, they're inherently dangerous you know". The recent fire at Luton airport shows pervasive this attitude is. Fires are being blamed on EVs even when they were not involved!
I predict that when electric powered flight becomes popular there will eventually be an electric powered passenger airplane that crashes and people die. This will cause millions of people to refuse to fly in them, despite the record of gas powered aircraft being far worse. If it happens early on - which is more likely with any new technology - it could set back the transition to sustainable flight by many years. But by that time we will probably be screwed anyway, if the public can't get out of its Luddite mindset.
Delvo
Дэлво Δε&#
I've seen two vehicles on fire in my life, and been aware of a third within several miles of me because it was big news in my city, while routinely seeing hundreds of non-burning ones per day. Any claim in the neighborhood of 1½ or 3½ per hundred of any category of vehicles burning is so obviously so far from anything even faintly resembling reality as to warrant no further consideration or "being taken up with" anybody in any way. The patent absurdity is simply beyond impossible to take seriously for a moment right on its face. It might as well have talking snakes & donkeys.
You're still getting the units wrong here in the same way I mentioned earlier. There's got to be some per unit time measure here for this to be meaningful at all. If the figures are meant to be over the lifetime of the car, and say that's ~20 years on average, then that's 1.5 or 3.5 cars /100 cars/20 years experiencing fires.
If you were constantly watching 100 cars, over the course of 20 years you'd see ~3 fires (if they were ICE vehicles). But you're not constantly watching them, and car fires don't last a whole day. You see those cars* for say a couple of hours/day. If the fire lasts on average for an hour, then you'd see all the fires that start within 1 hour of you seeing those cars, so call it 4 hours/day. So we're down to actually observing 1 fire/20 years. But you said "several hundred" so multiply that by "several", and we're back to say 2-5 fires/20 years, which is at least within a reasonable margin of what you actually observed.
*As I mentioned the fact that the fire lasts for a while mitigates the fact that you're not seeing all these cars at the same time, so I'm not going to complicate this too much by taking into account the fact that you only see each car for a short period of time, but this should still lower the total number of fires we predict you to observe here.