comment: >
  
  My understanding is that hydrogen powered anything (cars, planes, etc) opens up potential dangers because of human behavior and explosive energy of hydrogen. Making hydrogen car is essentially making a bomb on wheels because of what is needed to get the most output from the hydrogen with compression, etc. The tech has to be more refined for safe long term commercial and widespread use. 
  ON TOP OF THAT, the amount of 'energy' needed to get from water-> car is more energy required than it is electricity to car because of the process of moving hydrogen, turning water into hydrogen fuel cells, etc. We dont have the infrastructure setup for that, we dont have the refined processes in place for that.
  All that said, I think battery tech advances will out due hydrogen car advances, def room for both. Honestly I think we should move away from cars in general, but thats my take.
context: There are a few major drawbacks to using a hydrogen ICE. Namely fuel stability and power output. Maybe one day in the future it will become a viable option, but at the moment the technology couldn't keep up with commercial demands. >
  
  When comparing the two you always have to compare the relative ease of building out charging infrastructure vs. the enormous expense of building hydrogen infrastructure. Right now we don't produce much hydrogen, have limited ability to transport it, and almost no facilities to pump it into vehicles. Also, the cars themselves are not even being produced in quantity. 
  None of these problems exist for battery electric cars. All the electricity production and distribution networks have already been built (though some expansion will be required). Charging endpoints are the major infrastructure need at this time, and those are relatively cheap to install...like a couple orders of magnitude cheaper than hydrogen.
  Finally, battery tech is rapidly evolving. One of the key areas of study is battery chemistries that use less rare/expensive materials. It's likely that we have not yet seen the type of battery that will fully revolutionize our economy. Mining technology may also provide new sources of lithium if it's still required in large quantities.
  The last thing we can do is simply reduce our reliance on cars. Especially in cities, there are much better ways to create urban environments than building them around car use.
  edit: I forgot to mention that hydrogen may be the right solution for applications where a vehicle is far from civilization and has a lot of capacity to store fuel, such as a cargo ship. But even there battery tech may improve enough where it works for that application as well. Easier to recharge w/ solar panels than create hydrogen. >
  
  Good luck getting over the “million little Hidenbergs” on the road perception. >
  
  Those people clearly don’t know about lithium fires.  It’s true, hydrogen fires/explosions are no joke, however current Tesla batteries have 5 kilograms of lithium.  Lithium fires are fucking terrifying.
  Burns at 2,000°c, you can’t put it out with water as that can lead ironically to hydrogen explosions, are self oxidizing so can reignite if you smother them and spew extremely toxic smoke.
  I’d kinda prefer driving my own Hindenberg over dying in a lithium fire. >
  
  Hydrogen has really crappy low energy density, so you need to squeeze a lot of it into a high-pressure tank, which is not a fun thing to take out with you on the road.
  The other problem is that hydrogen atoms are tiny so they tend to work themselves into metal and make it more brittle.
  So now you have a brittle high-pressure tank bouncing around on the road with you (and possibly getting smacked in a collision).
  Solvable maybe with advanced composite materials but that might be really expensive. >
  
  Complete non-engineer here, so take my opinion for what it's worth.  That said, I think you (like many others) are missing the mark because you're focusing on only one part of the problem (lithium) and missing the greater up-stream problems.  In this case, the real problem with hydrogen powered cars is in the hydrogen generation and compression.
  In brief, while free-floating hydrogen is abundant in the atmosphere, it is much more efficient to use electrolysis to produce.  This is a very very power-intensive process, most of which comes from fossil fuels.  The hydrogen must then be compressed, another power-intensive process.  Through these processes alone, one think tank (Cato) calculates that hydrogen my be more carbon intensive than gasoline cars. (Of course, this could be remedied with nuclear or wind/solar power, but "green" hydrogen costs almost triple the price of hydrogen produced by conventional means).
  On top of this, because of the nature of the hydrogen cell process hydrogen engines are only 37% efficient, best case.  Purely electric cars are 90% efficient.
  In short, given current technology, hydrogen powered cars are never going to overtake electric cars.  There are still some fundamental physics problems that keep it out of reach.  This may change in the future, but for the moment it would seem that the only real competitor to gas is electric. >
  
  Isn't the current idea for making hydrogen Cars to use a hydrogen fuel cell to get electrical output to power an electrical car >
  
  Yes, but you have to fill that fuel cell with hydrogen. In order to do that, you have to build out all of the electrical infrastructure you would need for electrical cars, then add electrolysis machines at the end of it to separate and compress the hydrogen. This uses more electricity than it would to charge a battery electric vehicle. You fill your fuel cell, and the fuel cell then needs to generate electricity from the hydrogen, and most of your energy is lost in conversion. All in all, it's extra infrastructure and a whole lot more electricity needed to move the vehicle the same distance. >
  
  Ya I diffentily agree I was just saying >
  
  That's true but unfortunately, every single hydrogen car is a moving bomb. Don't even want to imagine what would happen if one crashed into something and the tank would crack a bit. Even worse if there's a spark, as it's also extremely flammable. >
  
  You realise that the explosive potential of a EV battery is way more above a hydrogen tank? >
  
  The risk of a hydrogen tank exploding is higher than that of a battery. >
  
  The only reason why this is “unpopular” to begin is because we have Tesla shareholders and other EV buyers who are very upset by the idea of competition. In short, they are just spamming social media like Reddit with their bullshit out of personal insecurity.
  But because the EV is not particularly sustainable, especially with regards to battery related metals, it is basically guaranteed that there will be a huge backlash against EVs. That will mostly end the unpopularity of this opinion. >
  
  Hydrogen cars are bombs on wheels >
  
  Unless you have an idea to make hydrogen to make really cheap, hydrogen is just an ev but worse >
  
  How would a hydro car work >
  
  Depends, it can either work with a somewhat modified combustion engine (see the bmw hydrogen 7) or with an hydrogen fuel cell (the inverse of electrolysis) where electrolysis uses electricity to split water into hydrogen and oxygen, the fuel cell lets them come together slowly in a process which produces electricity chemically (like a battery) >
  
  
  Depends, it can either work with a somewhat modified combustion engine
  
  I wonder if a hydrogen engine would be louder than a petro engine >
  
  My now alcohol fueled (well e85... 85% alcohol) car that I converted from regular gasoline sounds exactly the same as it did before.
  The exhaust smells very different though (for the better).
  Not the same as hydrogen of course and gasoline and alcohol are much more similar to each other than either is to hydrogen, but it's a data point for you. >
  
  The issue with hydrogen fuel cells is they use a layer of platinum to catalyze the reaction that creates energy.  The question we need to ask is can you scale up the production of hydrogen fuel powered cars and not have the same issues. >
  
  I think we fucked up big-time by not making cars that are hybrid but lean more towards electric than current hybrids. Basically they were an electric car with a tiny engine to recharge the battery, which doesn't have to be nearly as big. I think there were a few, but they had no market because the people who wanted them at all tended to just want full electric for some reason (probably felt it helped the environment more; "feels good" factor). I feel they were pretty much superior in every way--very low emissions and gas use and it solved some of the issues with these huge batteries. >
  
  Battery technology well improve to the point of not needing lithium >
  
  My understanding is that hydrogen powered anything (cars, planes, etc) opens up potential dangers because of human behavior and explosive energy of hydrogen. Making hydrogen car is essentially making a bomb on wheels because of what is needed to get the most output from the hydrogen with compression, etc. The tech has to be more refined for safe long term commercial and widespread use. 
  ON TOP OF THAT, the amount of 'energy' needed to get from water-> car is more energy required than it is electricity to car because of the process of moving hydrogen, turning water into hydrogen fuel cells, etc. We dont have the infrastructure setup for that, we dont have the refined processes in place for that.
  All that said, I think battery tech advances will out due hydrogen car advances, def room for both. Honestly I think we should move away from cars in general, but thats my take. >
  
  Hydrogen powered cars have low energy efficiency. Once you account for the conversion, it's barely more energy efficient than an ICE car. About 40% or so (which is similar to a modern hybrid). Battery electric is >85% efficient. >
  
  I think it's clear that the car with the greatest green credentials and is the obvious choice for the future. Ironically, such cars are from yesteryear and can be found well documented in video archives.
  The car of the future is, of course, The Flintmobile (also known as the Cavemobile). Constructed from just wood, rock, and animal hide (can be substituted for a more eco-friendly alternative). 
  There's also no need for either battery or hydrogen, since the car can draw power from the kinetic energy contained in the legs of the passengers.
  Really, the only words that can describe this technological marvel are Yabba-Dabba-Doo! >
  
  Cant wait ti turn my car into a hydrogen bomb and drive into >!redacted!< >
  
  I agree. Hydrogen can also be generated at a filling station and doesn't need to be transported. Spills wouldn't affect much for very long. It's only byproduct is water. 
  I didn't read all of OP's post because A. I'm lazy and 3. I agree with just the title so...sue me. >
  
  As someone who doesn’t know much about the subject, my first thought was “if it’s so much better than why is it not already being sold everywhere?” >
  
  So here's the thing All the problems with all the various technologies could eventually be solved
  The greatest improvement to our overall circumstances happens to be with electric
  Simply put it has the highest synergy with everything else
  If you make an improvement to battery storage it makes an improvement to battery storage not just for electric cars but for the whole grid
  Even ignoring that they're capable of functioning as extra storage for the grid
  In addition you don't need to create as much extra infrastructure if you go the electric route because the energy that can be used to power anything else can just be plugged in to the charging stations anywhere versus having to build a lot of specialized infrastructure for the storage and transport of hydrogen or gasoline or whatever other fuel you would like
  With regards to the material issues there is sufficient rare earth metals in low concentration around the Earth to be used for all purposes needed we are refining the technology of extraction to do it cleanly and efficiently this benefits not just electric cars but the entire grid is something we will be need to do anyway  
  Even if we decide not to go with refining our rare earth extraction methods we could simply find a new material that can perform the job better and cheaper with enough refinement
  There is very directly massive advantages to using the more synergistic technology >
  
  Yes but when you invent a hydrogen powered car you mysteriously die >
  
  but Toyota did and sells them >
  
  Hydrogen itself it’s cleaner energy, but isn’t it a major pain in the butt to store and transport them in their liquid form? Electric vehicles are indeed not as environmentally friendly as people think, perhaps not better then ICE cars, BUT it allows many countries to avoid a good amount of restrictions and control from the monopoly of the oil gas capitals form by the OPEC+ and US. >
  
  Using hydrogen in an ICE engine makes sense. Expecting a bunch of morons to fill them safely (just look at a gas pump for all the spilled fuel stains. Now picture that but with the smallest molecule spilling out everywhere, add extra safety points because it will be a hundreds of degrees below freezing) is not. 
  Add to that the extra maintenance to replace every seal in the fuel system, because again smallest molecule means easy and many leaks. 
  And too it all off with the fact that right now the cheapest way to get hydrogen is to make it from natural gas. And you use much more electricity and carbon output to make the fuel than just using a normal gas engine. >
  
  Hydrogen explodes. One car wreck would be a nightmare for EMTs and Fire Fighters. As it is, EVs are already nightmare fuel for firefighters. >
  
  There are a few major drawbacks to using a hydrogen ICE. Namely fuel stability and power output. Maybe one day in the future it will become a viable option, but at the moment the technology couldn't keep up with commercial demands. >
  
  Using hydrogen in an ICE engine makes sense. Expecting a bunch of morons to fill them safely (just look at a gas pump for all the spilled fuel stains. Now picture that but with the smallest molecule spilling out everywhere, add extra safety points because it will be a hundreds of degrees below freezing) is not. 
  Add to that the extra maintenance to replace every seal in the fuel system, because again smallest molecule means easy and many leaks. 
  And too it all off with the fact that right now the cheapest way to get hydrogen is to make it from natural gas. And you use much more electricity and carbon output to make the fuel than just using a normal gas engine. >
  
  When comparing the two you always have to compare the relative ease of building out charging infrastructure vs. the enormous expense of building hydrogen infrastructure. Right now we don't produce much hydrogen, have limited ability to transport it, and almost no facilities to pump it into vehicles. Also, the cars themselves are not even being produced in quantity. 
  None of these problems exist for battery electric cars. All the electricity production and distribution networks have already been built (though some expansion will be required). Charging endpoints are the major infrastructure need at this time, and those are relatively cheap to install...like a couple orders of magnitude cheaper than hydrogen.
  Finally, battery tech is rapidly evolving. One of the key areas of study is battery chemistries that use less rare/expensive materials. It's likely that we have not yet seen the type of battery that will fully revolutionize our economy. Mining technology may also provide new sources of lithium if it's still required in large quantities.
  The last thing we can do is simply reduce our reliance on cars. Especially in cities, there are much better ways to create urban environments than building them around car use.
  edit: I forgot to mention that hydrogen may be the right solution for applications where a vehicle is far from civilization and has a lot of capacity to store fuel, such as a cargo ship. But even there battery tech may improve enough where it works for that application as well. Easier to recharge w/ solar panels than create hydrogen. >
  
  We don't even have the energy capacity to fully shift to electric.  And the more stations that get added are going to see pay per charge instead of free.  You're also going to have taxes added into those charging stations like gas does, to cover road use and expenses.
  I remember seeing a Humvee electric they were displaying.  Stopped at a supercharger that was a pay station.  They paid as much in electricity as it would have cost in gas and they had to sit there for like an hour.
  Yes, hydrogen has has no distribution at this point, but we already have all the infrastructure needed in place due to gas distribution.  All a station needs is a commercial tank that can be placed anywhere on their lot.
  No, the torque is not up to speed with electric yet.  But, electric is only producing what power it does at the expense of range and recharge time.  1 tank goes about 550 miles in my SUV.  Electric in a similar vehicle would be about 250 safe miles before needing a charge.  Someone also cannot bring you a tank of electricity to get you to the next charger like you can with gas, or could do with hydrogen.  With a fuel cell in the car to supplement, hydrogen could even just be a matter of waiting 30 minutes till you have enough to get to a station.
  The argument swings back and forth.  Hydrogen is much closer to gas in terms of what we have now.  Stations need only minimal generator power to be able to continue to pump, it takes a couple of minutes to fill up, and the car basically behaves as a gas car would.
  I think a hybrid approach may be the best.  Ev's with a small hydrogen generator.  The generator can recharge the cells to greatly expand range, like gas hybrids do now.  You eliminate emissions, reduce the drawbacks of pure ev use and give people the same ability to refiel in a few minutes and move on.  Obviously there are challenges on that front as well if it is not already in development. >
  
  Good luck getting over the “million little Hidenbergs” on the road perception. >
  
  Those people clearly don’t know about lithium fires.  It’s true, hydrogen fires/explosions are no joke, however current Tesla batteries have 5 kilograms of lithium.  Lithium fires are fucking terrifying.
  Burns at 2,000°c, you can’t put it out with water as that can lead ironically to hydrogen explosions, are self oxidizing so can reignite if you smother them and spew extremely toxic smoke.
  I’d kinda prefer driving my own Hindenberg over dying in a lithium fire. >
  
  Complete non-engineer here, so take my opinion for what it's worth.  That said, I think you (like many others) are missing the mark because you're focusing on only one part of the problem (lithium) and missing the greater up-stream problems.  In this case, the real problem with hydrogen powered cars is in the hydrogen generation and compression.
  In brief, while free-floating hydrogen is abundant in the atmosphere, it is much more efficient to use electrolysis to produce.  This is a very very power-intensive process, most of which comes from fossil fuels.  The hydrogen must then be compressed, another power-intensive process.  Through these processes alone, one think tank (Cato) calculates that hydrogen my be more carbon intensive than gasoline cars. (Of course, this could be remedied with nuclear or wind/solar power, but "green" hydrogen costs almost triple the price of hydrogen produced by conventional means).
  On top of this, because of the nature of the hydrogen cell process hydrogen engines are only 37% efficient, best case.  Purely electric cars are 90% efficient.
  In short, given current technology, hydrogen powered cars are never going to overtake electric cars.  There are still some fundamental physics problems that keep it out of reach.  This may change in the future, but for the moment it would seem that the only real competitor to gas is electric. >
  
  Isn't the current idea for making hydrogen Cars to use a hydrogen fuel cell to get electrical output to power an electrical car >
  
  Yes, but you have to fill that fuel cell with hydrogen. In order to do that, you have to build out all of the electrical infrastructure you would need for electrical cars, then add electrolysis machines at the end of it to separate and compress the hydrogen. This uses more electricity than it would to charge a battery electric vehicle. You fill your fuel cell, and the fuel cell then needs to generate electricity from the hydrogen, and most of your energy is lost in conversion. All in all, it's extra infrastructure and a whole lot more electricity needed to move the vehicle the same distance. >
  
  Ya I diffentily agree I was just saying >
  
  Hydrogen has really crappy low energy density, so you need to squeeze a lot of it into a high-pressure tank, which is not a fun thing to take out with you on the road.
  The other problem is that hydrogen atoms are tiny so they tend to work themselves into metal and make it more brittle.
  So now you have a brittle high-pressure tank bouncing around on the road with you (and possibly getting smacked in a collision).
  Solvable maybe with advanced composite materials but that might be really expensive. >
  
  Hydrogen cars are bombs on wheels >
  
  That's true but unfortunately, every single hydrogen car is a moving bomb. Don't even want to imagine what would happen if one crashed into something and the tank would crack a bit. Even worse if there's a spark, as it's also extremely flammable. >
  
  
  That's true but unfortunately, every single hydrogen car is a moving bomb.
  
  Thanks for telling us you know absolutely nothing about hydrogen cars. >
  
  The most viable solutions, for now, include storing hydrogen under a pressure of 500 MPa or having it in cryotanks as liquid. Both of these technologies will result in a massive explosion if punctured near open flame.
  Metal hydrides and surface storage have still way too low energy densities and suffer from other drawbacks. >
  
  The only reason why this is “unpopular” to begin is because we have Tesla shareholders and other EV buyers who are very upset by the idea of competition. In short, they are just spamming social media like Reddit with their bullshit out of personal insecurity.
  But because the EV is not particularly sustainable, especially with regards to battery related metals, it is basically guaranteed that there will be a huge backlash against EVs. That will mostly end the unpopularity of this opinion. >
  
  Fuel cell cars were "the next big thing" a decade before Tesla launched the model S. They went nowhere, and not because of Tesla. >
  
  Unless you have an idea to make hydrogen to make really cheap, hydrogen is just an ev but worse >
  
  How would a hydro car work >
  
  Depends, it can either work with a somewhat modified combustion engine (see the bmw hydrogen 7) or with an hydrogen fuel cell (the inverse of electrolysis) where electrolysis uses electricity to split water into hydrogen and oxygen, the fuel cell lets them come together slowly in a process which produces electricity chemically (like a battery) >
  
  
  Depends, it can either work with a somewhat modified combustion engine
  
  I wonder if a hydrogen engine would be louder than a petro engine >
  
  My now alcohol fueled (well e85... 85% alcohol) car that I converted from regular gasoline sounds exactly the same as it did before.
  The exhaust smells very different though (for the better).
  Not the same as hydrogen of course and gasoline and alcohol are much more similar to each other than either is to hydrogen, but it's a data point for you. >
  
  The issue with hydrogen fuel cells is they use a layer of platinum to catalyze the reaction that creates energy.  The question we need to ask is can you scale up the production of hydrogen fuel powered cars and not have the same issues. >
  
  I think we fucked up big-time by not making cars that are hybrid but lean more towards electric than current hybrids. Basically they were an electric car with a tiny engine to recharge the battery, which doesn't have to be nearly as big. I think there were a few, but they had no market because the people who wanted them at all tended to just want full electric for some reason (probably felt it helped the environment more; "feels good" factor). I feel they were pretty much superior in every way--very low emissions and gas use and it solved some of the issues with these huge batteries. >
  
  Battery technology well improve to the point of not needing lithium