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New battery energy density in this article: 460 Wh/kg This is from an older article looking at model 3 energy density: 207 Wh/kg Tesla Model 3 Battery Cell

New battery energy density in this article: 460 Wh/kg This is from an older article looking at model 3 energy density: 207 Wh/kg Tesla Model 3 Battery Cell Has World's Highest Energy Density https://www.reddit.com/r/teslamotors/comments/bo27ia/tesla_battery_researcher_is_excited_about_new/enblk39?utm_source=share&utm_medium=web2x https://www.reddit.com/r/teslamotors/comments/bo27ia/tesla_b...

JackFr 7y ago
Gasoline 12,888 Wh/kg (I don't post this to be annoying contrarian in a discussion of battery tech. The externalities of burning carbon aside, it's just astonishing how effective gasoline is a relatively safe, stable means of transporting energy.) https://en.wikipedia.org/wiki/Energy_density https://en.wikipedia.org/wiki/Energy_density
- i80and 7y ago
  Not to detract from your point since gasoline is amazingly useful, but there's a gap between energy density and usable energy density. An Otto cycle has a maximum theoretical efficiency of up to 61%, but in practice, friction and powering auxiliary system result in closer to 35% efficiency for a gasoline engine. VERY rough spitballing not to be cited: ~4500 usable Wh/kg. Permanent magnet motors achieve upwards of 92% efficiency under optimal load, from the numbers I can find with quick googling.
  - throw20102010 7y ago
    Just to continue the discussion: 4,500 Wh/kg is still a 10x improvement on this new state of the art, and over a 20x improvement in current popular battery chemistries. Gas looks pretty good. Another thing to consider is the weight of the equipment needed to convert the stored energy into "whatever." For a car, that is the weight of the drivetrain. A typical car engine+transmission weighs 300-600 lbs depending on the size and power of the car. Two Tesla model S (no transmission needed) motors weigh around 150 lbs. This weight advantage is significant when you realize that 20 lbs of gas weighs 120 lbs. So when considering the density of a "useable system" with all necessary conversion equipment then electric is starting to catch up. Gas still looks best for most cars (also consider the convenience, and price factors), but I'm pretty sure gas will lose within our lifespans.
    - Skunkleton 7y ago
      Don't forget the charging system, and also that as batteries discharge they don't get lighter. Of course none of that matters. We need to ditch fossil fuels.
      - antepodius 7y ago
        Depends on how cheap it becomes to synthesize it from air using electricity, in which case it just becomes an alternate battery.
    - ksec 7y ago
      You are excluding the weight of battery which far outweighs the saving of Electric Motors.
      - throw20102010 7y ago
        No, I was including it. Adding 150 lbs to a 1,200 lb battery only reduces the overall energy density by 11%. Adding 360 lbs to a 120 lb tank of gas reduces energy density by 75%. Where gas originally appeared to have a density advantage of 20x, it's now down to a 6x advantage after factoring in powertrain weight. That is what I mean when I say that batteries are catching up if you consider the total weight of the system.
- helloguillecl 7y ago
  To the electric battery's advantage, electricity doesn't need to be "transported" until it reaches the car. Gasoline in the other hand needs an entire specialized and -I assume- expensive supply chain.
  - JackFr 7y ago
    >... and -I assume- expensive supply chain. Gasoline is literally the cheapest liquid sold at many gas stations -- in many places cheaper than bottled water.
- deleted 7y ago
  [deleted]
- cuban-frisbee 7y ago
  I would imagine that quiet operation of electric motors might also be quite attractive for the army.
- fiftyfifty 7y ago
  The energy in the batteries weighs almost nothing, the batteries are just the storage mechanism, like the gas tank. To make a fair comparison between these cars, you almost need to compare not just the weight of the fuel but the entire system to convert that fuel into kinetic energy: the weight of the engine, transmission, drive shaft, gas tank, fuel pump, oil, cooling system. There is almost 500Kg of stuff in a typical passenger car to convert that gasoline into motion, the transmission alone in some cars can weigh almost 100Kg. Right now a Tesla Model S weighs about 450Kg more than a comparable luxury car (Audi/BMW etc) and the battery pack (including cooling system etc) weights about 545Kg by itself. Another doubling of battery energy density would bring Teslas much closer in weight to a comparable gasoline car with the same range. In fact one would expect the range to go up for the Tesla by making it lighter as well. Teslas are notoriously heavy, even for an electric vehicle, an energy density of 400 Wh/Kg for batteries should bring weight parity between electric cars and gasoline cars for the same range and the same amount of cargo. That seems like the only weight number worth comparing.
- smuser 7y ago
  Probably worth considering the efficiency of converting that stored energy to useful work. Average ICE efficiency is ~20% yielding effective storage of ~2600 Wh/kg. Roughly an "order of magnitude" more density. EDIT: Hadn't refreshed the page since lunch. Many have made this point already. Apologies haha
- perilunar 7y ago
  Hydrogen is 33,314 Wh/kg — almost three times as much. And it can be used in a fuel cell at higher efficiency than burning gasoline. Pity it's energy density is so low.

JackFr 7y ago

Gasoline 12,888 Wh/kg (I don't post this to be annoying contrarian in a discussion of battery tech. The externalities of burning carbon aside, it's just astonishing how effective gasoline is a relatively safe, stable means of transporting energy.) https://en.wikipedia.org/wiki/Energy_density https://en.wikipedia.org/wiki/Energy_density

i80and 7y ago
Not to detract from your point since gasoline is amazingly useful, but there's a gap between energy density and usable energy density. An Otto cycle has a maximum theoretical efficiency of up to 61%, but in practice, friction and powering auxiliary system result in closer to 35% efficiency for a gasoline engine. VERY rough spitballing not to be cited: ~4500 usable Wh/kg. Permanent magnet motors achieve upwards of 92% efficiency under optimal load, from the numbers I can find with quick googling.
- throw20102010 7y ago
  Just to continue the discussion: 4,500 Wh/kg is still a 10x improvement on this new state of the art, and over a 20x improvement in current popular battery chemistries. Gas looks pretty good. Another thing to consider is the weight of the equipment needed to convert the stored energy into "whatever." For a car, that is the weight of the drivetrain. A typical car engine+transmission weighs 300-600 lbs depending on the size and power of the car. Two Tesla model S (no transmission needed) motors weigh around 150 lbs. This weight advantage is significant when you realize that 20 lbs of gas weighs 120 lbs. So when considering the density of a "useable system" with all necessary conversion equipment then electric is starting to catch up. Gas still looks best for most cars (also consider the convenience, and price factors), but I'm pretty sure gas will lose within our lifespans.
  - Skunkleton 7y ago
    Don't forget the charging system, and also that as batteries discharge they don't get lighter. Of course none of that matters. We need to ditch fossil fuels.
    - antepodius 7y ago
      Depends on how cheap it becomes to synthesize it from air using electricity, in which case it just becomes an alternate battery.
  - ksec 7y ago
    You are excluding the weight of battery which far outweighs the saving of Electric Motors.
    - throw20102010 7y ago
      No, I was including it. Adding 150 lbs to a 1,200 lb battery only reduces the overall energy density by 11%. Adding 360 lbs to a 120 lb tank of gas reduces energy density by 75%. Where gas originally appeared to have a density advantage of 20x, it's now down to a 6x advantage after factoring in powertrain weight. That is what I mean when I say that batteries are catching up if you consider the total weight of the system.
helloguillecl 7y ago
To the electric battery's advantage, electricity doesn't need to be "transported" until it reaches the car. Gasoline in the other hand needs an entire specialized and -I assume- expensive supply chain.
- JackFr 7y ago
  >... and -I assume- expensive supply chain. Gasoline is literally the cheapest liquid sold at many gas stations -- in many places cheaper than bottled water.
deleted 7y ago
[deleted]
cuban-frisbee 7y ago
I would imagine that quiet operation of electric motors might also be quite attractive for the army.
fiftyfifty 7y ago
The energy in the batteries weighs almost nothing, the batteries are just the storage mechanism, like the gas tank. To make a fair comparison between these cars, you almost need to compare not just the weight of the fuel but the entire system to convert that fuel into kinetic energy: the weight of the engine, transmission, drive shaft, gas tank, fuel pump, oil, cooling system. There is almost 500Kg of stuff in a typical passenger car to convert that gasoline into motion, the transmission alone in some cars can weigh almost 100Kg. Right now a Tesla Model S weighs about 450Kg more than a comparable luxury car (Audi/BMW etc) and the battery pack (including cooling system etc) weights about 545Kg by itself. Another doubling of battery energy density would bring Teslas much closer in weight to a comparable gasoline car with the same range. In fact one would expect the range to go up for the Tesla by making it lighter as well. Teslas are notoriously heavy, even for an electric vehicle, an energy density of 400 Wh/Kg for batteries should bring weight parity between electric cars and gasoline cars for the same range and the same amount of cargo. That seems like the only weight number worth comparing.
smuser 7y ago
Probably worth considering the efficiency of converting that stored energy to useful work. Average ICE efficiency is ~20% yielding effective storage of ~2600 Wh/kg. Roughly an "order of magnitude" more density. EDIT: Hadn't refreshed the page since lunch. Many have made this point already. Apologies haha
perilunar 7y ago
Hydrogen is 33,314 Wh/kg — almost three times as much. And it can be used in a fuel cell at higher efficiency than burning gasoline. Pity it's energy density is so low.