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Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

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Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#401
post #370

FWIW: the material challenges for hydrogen are such that I do not think that it will ever be a mainstream storage medium for vehicular use (it's not a fuel, it is a battery). - hydrogen embrittlement - leakage from whatever container you plan to use - very low activation energy -> always danger of explosion So it's a great thing in the lab and to get subsidy for but it sucks for large scale deployment, and deploying…

I think if you are going to go with a highly energy inefficient storage medium then methane makes more sense. It's a lot more practical to transport and store. It can be carbon neutral as well if you use sabatier generators or bio reactors instead of fossil fuels. You can convert existing ICE engines to use it too. It's definitely not ideal, but it's still a fair bit better than the hydrogen options which generally j…

Indeed, methane makes a lot more sense.

As for that bus:

I saw that here when it happened. Note the vehicles passing by when the bus is already on fire, I really wonder what was so urgent they felt they had to take that risk.

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#402

Earlier quoted context omitted.

But it is much faster to fill-up an hydrogen tank then it is to charge a battery.

Really? It takes me about 5 seconds to charge my car every day, and I don't even need to leave my house to do it.

It takes 5 seconds if your car was not completely empty and you don't need to go somewhere else. Hydrogen could be easily created at home too.

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#403

Earlier quoted context omitted.

Apart from some freak events that happen every 50 years -50C doesn't _really_ happen anywhere settled in Canada. Even a place like Inuvik, the coldest temp ever recorded was -56.7C but only for a few minutes... in 1968. Edmonton gets a few nights where it can get below -40C every once in a while, but it's not common and again, it's not all night. Frankly it just sounds like he's confusing actual temperature with wind…

Fort McMurray Alberta. Not exactly the end of the earth. It is often colder than the far north because it is far from the ocean. May 19th today. There is snow on the ground. Every year there is a week or two of -40, not wind-chill, temperature. Nobody who actually lives in the north misunderstands wind-chill.

Quite familiar with Fort Mac, have family on both sides there and spent Christmas there every couple years.

It doesn't get to -50C, except as severe outlier. -40C in overnights for short periods of time in the winter.

Average temps: https://images.climate-data.org/location/4623/climate-graph....

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#404

Earlier quoted context omitted.

> This is at 66.9 km/h (40 mph) in order to greatly increase its range due to lower drag compared to normal highway speeds. > As a comparison a Tesla Model 3 got 975km (606 miles) at 40 km/h (25 mph) [1]. I can't seem to find any range tests at a similar speed as the Nexo. > It doesn't seem like current fuels cell have much of a energy density / range advantage even though hydrogen itself is much more energy dense, t…

Drag isn't the only thing in play. They both are driving below highway speeds, one more so than the other, I wish there was some data for a Tesla at 40 mph vs 25 or 48 to compare more directly the difference. The Tesla will have between 975 and 708km range at 40 mph the NEXO is 887km, I will make an assumption the Tesla is less, but how much less, is it "much" different? What is the energy density delta between a HFC…

Doesn't matter much. Below about 80km/h rolling resistance is dominant.

>What is the energy density delta between a HFCV and BEV currently?

Depends on what you're counting. Mirai's fuel cell stack, composite overwrapped tank, additional underbody and rear impact crash protection, high pressure filling system, cooling and fan intake system, and lithium battery together masses well over 400kg. Also takes up a lot of cabin and cargo space necessitating a larger vehicle.

Tesla's new 4680 batteries form part of the vehicle's structure and add free torsional rigidity, and will weigh roughly the same as a fuel system for 600km range. I imagine in the compact they'll package it into the unused area under the rear seat in order to drop the floor which should help with CdA.

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#405
post #384

Earlier quoted context omitted.

I have to wonder how much of that is down to the way the driving habits of people who buy a car labeled "long range" differ from those who buy one that calls itself "performance". It doesn't really refute the notion that the difference between measured and claimed performance is due to the different driving conditions being tested. IIRC there was some youtube video a year or two back that tested a few variants on a t…

AFAIK, Tesla uses the same range estimate for all trim levels of the Model 3 (or did in 2019, at least). The problem is that the Performance trim has 20 inch non-aero wheels and sticky tires. I got 325+ Wh/mi steady state cruise on the highway using AP to do the driving (in good weather; was 350+ when colder). There have been some independent tests and IIRC the consensus is that the standard range Model 3 was rated p…

The current site lists the LR at 353 miles EPA range and the performance at 315.

But again, you're using the words "on the highway" to reflect what I assume to be your driving habits in rural open road conditions and not the test that was actually performed to produce the numbers in the product specs. And that was my point. It's not about advertising fidelity at all, it's about regulation and its mismatch with the expectations of a modern EV driver.

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#406

Earlier quoted context omitted.

More than a gasoline bomb, hopefully. Gasoline is more dangerous.

I'm relatively sure that a tank of hydrogen at ridiculous pressure makes a nicer fireball than a tank of gas at no pressure.

No: it's a myth that a hydrogen tank simply explodes. It would need to be mixed with oxygen.

Instead, liquid flammables can leak around and then ignite.

https://www.computerworld.com/article/2852323/heres-why-hydr...

https://hydrogen.wsu.edu/2017/03/17/so-just-how-dangerous-is...

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#407
post #398

Earlier quoted context omitted.

The dynamics of moving heavy loads long distances has never favored electric power. Diesel currently powers tractor semis because it produces more energy than gasoline and creates much more low speed continuous load torque. EVs are well suited to light loads and short distances, rapid acceleration and altitude change but are not well suited to long range hauling of heavy loads due to the enormous energy required.

EVs are great if you are pulling heavy loads across hills, as you get your energy back going downhill (at least large parts of it). The torque also rather is an advantage of EVs. Diesel engines are popular because they are more efficient than gasoline engines and if you have continuous high loads, that adds up. Guess what is much more efficient than Diesel engines? Electric engines! And they are way more efficient th…

An electric semi's battery weight alone makes them not viable imo. I think it's a good idea to ignore the endless Tesla sales hype and brand reinforcement and focus on the basic logic and physics. Musk is as fake as his hair imo and spends most of his time being very misleading while aggressively selling theoretical future projects.

I grew up in the UK with electric milk floats, a practical use of EV's for short, quiet urban delivery. There's a reason electric heavy trucks, which were marketed in the 20's and 30's lost out to diesel. https://en.wikipedia.org/wiki/Walker_Electric_Truck

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#408

Earlier quoted context omitted.

Few kg of hydrogen are surely more dangerous than 50 kg of gasoline.

The total amount isn't as much a problem as is the activation energy. Hydrogen will explode when you look at it cross eyed. For gasoline you will have to do some work.

Hydrogen does not explode unless mixed with oxygen or other comburents.

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#409

Earlier quoted context omitted.

> Hydrogen cars have tiny batteries that don't need to support fast charging. Because that's what they think consumers want, not because of technological limitations. Size is not a requirement for high power batteries. The Porsche 918 has a 6.8 kWh battery that can do 210 kW. That's ~31 kW per kWh, compared to a top-end Model S at ~6 kW/kWh.

Yes, a $800K Hydrogen car would probably have a small but high power battery. But Nexo's and Mirai's don't.

High power batteries aren't like high power engines. They're built on the same production lines. High power engines prioritize power over cost; high power batteries just prioritize it over capacity.

It's not challenging to make a cheap, small battery that can provide 200 kW. It just happens that it hasn't been prioritized.

A provable example: 1,826 Sony VTC4 18650 cells will push 200 kW continuously. That's only 14 kWh of storage and weighs That would almost triple (136 -> 336) the Mirai's power and put it (2050 kg @curb) in spitting distance of the 550i (390 kW, 2020 kg @curb). The BMW's MSRP starts 27k USD higher.

Of course you would need to change the suspension and geometry completely, make the interior far nicer, and add even more power to be able to actually compete with the 550i, but the point stands. A small, powerful battery is cheap and easy to add to a FCV.

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#410

Earlier quoted context omitted.

Yes, a $800K Hydrogen car would probably have a small but high power battery. But Nexo's and Mirai's don't.

High power batteries aren't like high power engines. They're built on the same production lines. High power engines prioritize power over cost; high power batteries just prioritize it over capacity. It's not challenging to make a cheap, small battery that can provide 200 kW. It just happens that it hasn't been prioritized. A provable example: 1,826 Sony VTC4 18650 cells will push 200 kW continuously. That's only 14 k…

If you are wiring all 1826 cells in parallel, that means you need 1826 battery controllers to achieve reasonable life and reliability. Plus the hassle and cost of using bus bars instead of wires. And it means that the battery module output is 3.6V at an insane amperage and needs a massive transformer for a reasonable voltage.
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