How Safe are our vehicles, in particular EVs?

GeoffL said:
In some ways that makes sense since the cost of transporting hydrogen at extreme pressures probably makes central generation non-viable. However, production of hydrogen from hydrocarbons probably isn't viable
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Neither viable nor green A bad idea.
GeoffL said:
at the point of delivery and even that produced by electrolysis might not be viable as each filling station would require a huge supply of electricity
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Doesn't seem to stop them installing fast charging for EVs, whch has the same requirements.

GeoffL said:
and a (certified and regularly inspected) compressor as well as tanks capable of withstanding circa 700 to 1,400 atmospheres (assuming normal testing of pressure vessels of 2 x working pressure) and the testing routine will need to be carefully considered
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Just like they have do do for the underground fuel storage tanks.
GeoffL said:
since (as the Titan submersible showed) pressure vessels can only take a number of cycles before structural fatigue occurs.
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Titan was holding pressure out of the tank, not in it. A much more challenging problem.

GeoffL said:
Also, the amount of hydrogen stored in a tank (either at the filling station or in vehicle) is a tiny fraction of the overall mass (e.g. < 6% for a Toyota Mirai). So converting the fleet to hydrogen will require rather a lot of steel and other metals. That's not to say these issues are insurmountable, but synthetic hydrocarbon fuels might prove an easier solution.
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The fuel density of hydrogen is so high that a tankful of hydrogen, kilo for kilo, is about the same as a tank of petrol, diesel or LPG, even with the tank, It is far, far lighter than lithium ion batteries of the same capacity.

Symthetic hydrocarbons produce CO2 out of the tailpipe. Hydrogen doesn't.
 
Extracts from 2 articles in the New York Times. (Cant't post the links due to paywall).


CALIFORNIA TODAY

Batteries in E-Bikes and Other Devices Are Sparking Fires in San Francisco​

Two people jumped out of an apartment window on Monday to escape what was the city’s 24th fire this year linked to rechargeable batteries.

and from New Yrok City New ....................

Across the country, over 200 micro-mobility fire or overheating incidents have been reported from 39 states, resulting in at least 19 fatalities, according to the United States Consumer Product Safety Commission. But the organization emphasized that the problem is particularly acute in densely populated areas like New York City. In London, lithium battery fires are the fastest-growing fire risk, with 57 e-bike fires and 13 e-scooter fires this year, according to the London Fire Brigade.

In New York, lithium battery fires have killed 13 people so far this year, including four people in a blaze that started in an e-bike store in Chinatown on Tuesday. A total of 23 people have died in battery fires since 2021. This year, there have been 108 fires so far, compared with 98 fires for the same period last year.

Jeremy
 
Geek said:
Symthetic hydrocarbons produce CO2 out of the tailpipe. Hydrogen doesn't.
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You seem to be labouring under the misunderstanding that a trace gas essential to life is a pollutant. Hydrogen as a fuel produces dihydrogen monoxide out of the tailpipe, which can actually be dangerous and is a far more potent greenhouse gas!

Geek said:
Doesn't seem to stop them installing fast charging for EVs, whch has the same requirements.
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That to my noting that hydrolysis at filling stations requires a huge supply of electricity.
Actually, it does stop them from installing sufficient fast charging for EVs. The grid simply cannot cope and most charging facilities seem to be limited -- so the more cars on charge, the lower the current each gets. That said, the requirement for H2 is more than for EVs. While >90% of electrical energy fed to a charger is transferred to an EV's 'fuel tank', hydrolysis is relatively inefficient (<75%) and efficiency of H2 as fuel in fuel cells is only about 60% compared with over 90% efficiency of lithium batteries. Bottom line is that the electricity requirement for hydrogen is approximately double that required to charge EVs.
That said, people are desperately trying to improve both efficiencies for hydrogen, but they're not there yet by a long way.

Geek said:
Just like they have do do for the underground fuel storage tanks.

Titan was holding pressure out of the tank, not in it. A much more challenging problem.
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  1. Underground fuel storage tanks are not pressure vessels and so not subject to the same considerations. Your point is non sequitur.
  2. The pressure at which Titan failed as was circa 350 atmospheres. High pressure H2 is stored between 350 and 700 atmospheres, requiring test pressures of up to 1,400 atmospheres (i.e. four times the pressure that destroyed Titan).
 
GeoffL said:
You seem to be labouring under the misunderstanding that a trace gas essential to life is a pollutant. Hydrogen as a fuel produces dihydrogen monoxide out of the tailpipe, which can actually be dangerous and is a far more potent greenhouse gas!


That to my noting that hydrolysis at filling stations requires a huge supply of electricity.
Actually, it does stop them from installing sufficient fast charging for EVs. The grid simply cannot cope and most charging facilities seem to be limited -- so the more cars on charge, the lower the current each gets. That said, the requirement for H2 is more than for EVs. While >90% of electrical energy fed to a charger is transferred to an EV's 'fuel tank', hydrolysis is relatively inefficient (<75%) and efficiency of H2 as fuel in fuel cells is only about 60% compared with over 90% efficiency of lithium batteries. Bottom line is that the electricity requirement for hydrogen is approximately double that required to charge EVs.
That said, people are desperately trying to improve both efficiencies for hydrogen, but they're not there yet by a long way.


  1. Underground fuel storage tanks are not pressure vessels and so not subject to the same considerations. Your point is non sequitur.
  2. The pressure at which Titan failed as was circa 350 atmospheres. High pressure H2 is stored between 350 and 700 atmospheres, requiring test pressures of up to 1,400 atmospheres (i.e. four times the pressure that destroyed Titan).
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Sorry, but nearly every one of your points is just plain incorrect.

If anyone else would like me to explain how in more detail, I'll do so, but clearly you have a Trumpian view of the subject.
 
Started of talking about ev s andnow some one is blowing a trumpian, coubrian word for trumpet. 😂
 
That's the thing about language; it evolves all the time and one word can have several different, unrelated meanings.
 
I've decided to use an extension lead to charge my bike battery outside the van when I'm away (and the house when at home). E scooters apparently have problems too so it can't just be the additional power the car batteries have. Is it safer to be on the train or a ferry ?
 
I think it depends on the bike or scooter.
The fires are almost all caused by cheap Chinese brands that you've never heard of.

The quality makes have better quality batteries and better charger systems. Nevertheless, it's wise to take a precautionary approach.

It's also true of tumble driers and fridges with propane* refrigerant and plastic backs.

*They don't call it propane, but that's more or less what it is.
 
Geek said:
I think it depends on the bike or scooter.
The fires are almost all caused by cheap Chinese brands that you've never heard of.

The quality makes have better quality batteries and better charger systems. Nevertheless, it's wise to take a precautionary approach.

It's also true of tumble driers and fridges with propane* refrigerant and plastic backs.

*They don't call it propane, but that's more or less what it is.
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My bike battery is a Bosch but don't know how many components are made in China 🤣
 
Yashmac said:
My bike battery is a Bosch but don't know how many components are made in China 🤣
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Probably all of them. I've got the Bosch system as well but I'm confident about their quality control standards. That said I never leave the batteries charging unattended and would never charge them overnight, same in the van. There really does need to be some system of regulation with all the unbranded crap coming in and starting so many fires.
 
I suppose it's possible the Bosch ones are made in China, but who by? China is like any country, there are good and bad companies, and within them good and bad employees.
 
Geek said:
I think it depends on the bike or scooter.
The fires are almost all caused by cheap Chinese brands that you've never heard of.

The quality makes have better quality batteries and better charger systems. Nevertheless, it's wise to take a precautionary approach.

It's also true of tumble driers and fridges with propane* refrigerant and plastic backs.

*They don't call it propane, but that's more or less what it is.
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FWIW we've stopped charging of our eBike batteries indoors, but we still have a frighteningly high number of devices powered by lithium batteries (phones, mifi, laptop, tablet, torches, etc., etc., -- even the whisk we use in the van to get frothy coffee). However, at 612 Wh each, our eBike batteries are by far the biggest risk.

Regarding "quality makes have better quality batteries", it might be worth remembering that Samsung and Apple are generally regarded as "quality makes", yet Samsung have had repeated problems and there are several reports of (albeit old) iPhones bursting into flames. It's worth considering that most, if not all, current EV batteries are Chinese, we're now seeing rebadged Chinese EVs (e.g. MG) in this country, and China has a huge problem with EVs bursting into flames (an issue the CCP seem to be doing their best to hide). Hopefully, those imports will be scrutinised under the higher UK standards, but then we also have "Dieselgate" as evidence that companies will find ways to circumvent standards where an additional profit can be made.

Re. tumble driers: for once we agree: those really are fires in waiting. Lint builds up inside the casing enough to eventually contact the heating coil. I've had one tumble drier (Hotpoint) go up in flames. Hotpoint replaced that with a unit they later again replaced under recall for the same issue. In the meantime, my wife managed a home for elderly, visually impaired people and they had an industrial Miele dryer that did the same. I now annually vacuum away the lint -- and it's scary how much I find there each year.

 
We used to charge overnight, but not for a few years when Samsung phones were catching fire, all done during the day, and my phone has an alarm app to tell me when it is fully charged, so I unplug it and they are all off overnight.
 
Well there's a thing. I was convinced my Bosch e-bike batteries were Chinese. Just had a look, one is manufactured in Hungary,the other in Poland and the charger in Vietnam.
 
korky said:
Well there's a thing. I was convinced my Bosch e-bike batteries were Chinese. Just had a look, one is manufactured in Hungary,the other in Poland and the charger in Vietnam.
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The chances are that eBike batteries are made of 18650 cells. The most reputable are from Sanyo, Samsung, LG and Panasonic (Japanese and Korean companies), although I suspect a high probability that manufacture might be outsourced to China. The Hungarian and Polish manufacturers probably just assembled the final product from components made in various locations, and might include "Chinese knock off" cells...
 
Geek said:
Sorry, but nearly every one of your points is just plain incorrect.

If anyone else would like me to explain how in more detail, I'll do so, but clearly you have a Trumpian view of the subject.
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Sorry, but you seem to have a fantasy view of the subject. The only points I made that might be 'incorrect' are grid capacity and efficiency of conversion of electricity -- and even then the status quo is as I noted.

  1. CO2 is not a pollutant no matter what climatards might say. It is essential for photosynthesis, which is essential for plant life, which is essential for almost every other form of life on the planet: i.e. CO2 is essential for life. Average atmospheric concentration is circa 0.04% (~420 ppm) and is close to CO2 'drought' conditions. At 280ppm, CO2 concentration is only just enough to sustain plant life and almost all plant life will die if CO2 levels fall to 150ppm.
  2. Grid Capacity: Grid capacity right now is ~76GW. An average EV will be recharged at night at home (extortionate pricing at public fast charge points ensures that). There are ~ 33 million cars on the UK roads with each requiring 7kW if 100% EVs -- i.e. a total load of 231GW: i.e. approximately three times the grid capacity -- and that's without considering other EVs (e.g. buses and lorries) and without considering domestic and commercial loading that, right now, needs the existing 76GW. EVangelists insist that it'll be OK because all those vehicles won't be charged at the same time. However, typical work patterns means the majority will arrive home and be put on charge within the same 2-hour window and hence rationing is pretty much guaranteed. (clicky link) Local substation capacity will probably also be an issue.
  3. Efficiency of hydrogen as a fuel: Hydrolysis is considerably less efficient than batteries as an energy storage medium. Searching further after my previous post, it seems I was slightly incorrect as there are hydrolysis plants that can achieve 80%. However, current fuel cells are only 60% efficient. That further research shows Li-ion batteries can be more than 99% efficient under the right charging regime but the chargers themselves (esp. AC chargers) are typically 75% to 95% efficient. So, I re-did my calculations using 85% charger efficiency but retaining 90% battery efficiency: for a typical EV, it takes 130W of electricity to produce 100W of motive power. For hydrogen at 80% hydrolysis efficiency and 60% fuel cell efficiency, it takes 208W of electricity to produce 100W of motive power. That is, hydrogen requires 60% more electricity (90% if the battery is charged optimally) for the same motive power. (clicky link 1, clicky link 2, clicky link 3, click link 4)
  4. As stated, underground (diesel/petrol) fuel storage tanks are not pressure vessels. For that, they are vented to ensure there is no pressure build up! Also the pressures I gave in my previous posts are as stated, with the upper test pressure (1,400 atmospheres) being subject to the "twice working pressure" test pressure requirement for many pressure vessels.
These are facts, they may be inconvenient; but they are not optional...
 
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