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CATL has announced a new “condensed” battery with 500 Wh/kg

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Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#271

Post by robnado »

2OEH8eoCRo0 wrote: post #258
leoedin wrote: post #189

Earlier quoted context omitted.

The big reason for this is thermodynamics. A conventional internal combustion engine car has to convert chemical energy to kinetic energy - the absolute best theoretical efficiency of this might be 70%, but in practice it's more like 30%. Electric cars have to pay the same thermodynamic penalty, but they pay it at the power station (In practice, thanks to renewables, not all the electricity used to charge a car will…

ICE converts chemical energy to mechanical energy but an electric vehicle still has to convert electrical energy to mechanical energy.

The battery converts from chemical energy to electrical energy and the motor of the vehicle converts from electrical to mechanical energy.

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#272

Post by bb123 »

tecleandor wrote: post #200
msravi wrote: post #133

I just realized how much energy efficiency is being squeezed out of a Tesla. It's incredible. A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg, which is 13.2 km/l or 15.3 km/kg. Diesel has a mind-boggling 12700 Wh/kg energy density[1], which translates to an efficiency of ~827 Wh/km for the Chevy. By contrast, the Tesla Model S, has a ~540 kg battery[2]. At 272 Wh/kg (from the posted ar…

31mpg is not very efficient. Lots of current diesel engines in Europe are certified at 50+MPG. There's even a Car and Driver test where, with very efficient (and boring) driving you can get 70+MPG out of a Diesel Cruze... https://www.caranddriver.com/news/a15341744/the-prince-of-pa...

The U.S. uses a Gallon measurement which is about 20% smaller than an international one so you have to factor that in.

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#274

Post by masklinn »

grosun wrote: post #212
VulgarExigency wrote: post #203

Earlier quoted context omitted.

Not that confusing, only the US measures fuel in gallons, isn't it? Everyone else just uses liters.

The UK may be the most confusing; fuel is sold in litres, but fuel efficiency is expressed in MPG, and furthermore the gallons aren't the same as US gallons. I guess at least the miles are the same!

> I guess at least the miles are the same!

Only since the 1958 International Yard and Pound Agreement tho. Before then the US used what is now known as the Survey Mile, which is why the survey mile exists (and survived until this year).

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#275

Post by rkangel »

zamnos wrote: post #241
leoedin wrote: post #189

Earlier quoted context omitted.

The big reason for this is thermodynamics. A conventional internal combustion engine car has to convert chemical energy to kinetic energy - the absolute best theoretical efficiency of this might be 70%, but in practice it's more like 30%. Electric cars have to pay the same thermodynamic penalty, but they pay it at the power station (In practice, thanks to renewables, not all the electricity used to charge a car will…

> the absolute best theoretical efficiency of this might be 70% I fell down a rabbit hole and found this link, which gives 46% for the theoretical limit for the efficiency of the internal combustion engine. https://physics.stackexchange.com/questions/98966/maximum-th...

It's a different metric but it is generally accepted that F1 cars have reached an overall thermal efficiency of 50%, which is cool. This is taking into account energy recovery from kinetic (regenerative braking) and thermal sources (from the turbo).

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#276

Post by manmal »

jillesvangurp wrote: post #50
idontwantthis wrote: post #4

Why does 500wh/kg make electric aircraft possible? 6x less than kerosene. Is that the break even on cost if you can source very cheap electricity? Seems like it would still annihilate the payload/range.

Well, they were already possible and being sold. But with relatively short but usable ranges. Those now more than double with this battery. Which makes those planes usable in a lot more scenarios. Consider the Eviation Alice, one of the 9 passenger prototype electrical planes that is currently undergoing test flights (i.e. it definitely works). The advertised range is 250nm. Not amazing. But far enough for a lot of r…

Just a naive question, would having 10 planes not also make personnel way more expensive - you’d need 20 pilots instead of 2?

OTOH, security costs and airport fees could be cut I guess?

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#277

Post by masklinn »

spacebanana7 wrote: post #229
grosun wrote: post #212

Earlier quoted context omitted.

The UK may be the most confusing; fuel is sold in litres, but fuel efficiency is expressed in MPG, and furthermore the gallons aren't the same as US gallons. I guess at least the miles are the same!

I suspect the British fuel system is designed to hide the cost per mile of driving, at least tacitly. At present it's difficult to work out without some external tool.

An other possibility is that the brits like having wonky things, just look at the pre-decimalisation monetary system, or the counties (https://youtu.be/hCc0OsyMbQk).

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#278

Post by [deleted] »

grosun wrote: post #212
VulgarExigency wrote: post #203

Earlier quoted context omitted.

Not that confusing, only the US measures fuel in gallons, isn't it? Everyone else just uses liters.

The UK may be the most confusing; fuel is sold in litres, but fuel efficiency is expressed in MPG, and furthermore the gallons aren't the same as US gallons. I guess at least the miles are the same!

[deleted]

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#279

Post by 2OEH8eoCRo0 »

robnado wrote: post #271
2OEH8eoCRo0 wrote: post #258

Earlier quoted context omitted.

ICE converts chemical energy to mechanical energy but an electric vehicle still has to convert electrical energy to mechanical energy.

The battery converts from chemical energy to electrical energy and the motor of the vehicle converts from electrical to mechanical energy.

Ah. My point was more that there are losses assocated with these conversions and you can't move all of it to the upstream power plant. ICE vehicles burn fuel and create rotational mechanical energy which other than gear reductions doesn't require conversion. Electric does chemical -> electrical and then electrical -> mechanical with losses at each step here right?

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#280

Post by littlestymaar »

zamnos wrote: post #241
leoedin wrote: post #189

Earlier quoted context omitted.

The big reason for this is thermodynamics. A conventional internal combustion engine car has to convert chemical energy to kinetic energy - the absolute best theoretical efficiency of this might be 70%, but in practice it's more like 30%. Electric cars have to pay the same thermodynamic penalty, but they pay it at the power station (In practice, thanks to renewables, not all the electricity used to charge a car will…

> the absolute best theoretical efficiency of this might be 70% I fell down a rabbit hole and found this link, which gives 46% for the theoretical limit for the efficiency of the internal combustion engine. https://physics.stackexchange.com/questions/98966/maximum-th...

note that this is true for spark ignition engines, but not all ICE, diesel engines can reach higher efficiency and there are even real diesel engines with almost 50% efficiency[1], obviously not in cars though.

[1]: https://engineerine.com/meet-wartsila-31-worlds-most-efficie...

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