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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

#261

Post by iSnow »

cultureswitch wrote: post #204
theK wrote: post #110

Earlier quoted context omitted.

I’m afraid these bans get systematically sabotaged by well funded ice lobby groups. Just look at what happened to the EU’s ice ban for personal vehicles. Spoiler: while new gasoline burning cars are technically banned after 2035 it will be completely legal to sell new gasoline burning cars by labelling them e-fuel only…

The timelines for ICE bans within a decade are ridiculous from a technology and market standpoint and terrible for the environment. The best car technology is the one you don't use much. And we already have decades of cars in good enough condition to be driven weekly rather than daily. EVs will barely scratch the surface of environmental issues with transportation. And they will create a new range of supply problems…

I haven't heard of any country that wants to ban existing ICE cars.

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

#262

Post by thedrbrian »

sdenton4 wrote: post #12
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.

ICE engines only manage to turn ~15% of the stored energy in gasoline into actual work. A bit of googling suggests that jet engines are about 35% efficient. Stored electricity is much more efficiently turned into mechanical work... Electric engines have 75-90% efficiency. So, you get a lot more work or unit of stored energy.

table on wikipedia says the 15% thing might be out of date.

https://en.wikipedia.org/wiki/Brake-specific_fuel_consumptio...

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

#264

Post by bb123 »

oblio wrote: post #142
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…

That's about the same efficiency as every modern EV. This is not Tesla specific. Electric motors are very efficient, regenerative braking helps, EVs are designed to be super aerodynamic, etc.

That is not quite true - you’re right that it is not Tesla specific but many current EVs are far less efficient: https://insideevs.com/news/567087/bev-epa-efficiency-compari...

Particularly German made ones, for some reason.

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

#265

Post by pbmonster »

EVa5I7bHFq9mnYK wrote: post #143

Can some energy be recuperated on descent, blades turning in reverse?

Sure, completely possible in theory.

That would of course be equivalent of deploying an air brake almost the size of the rotor/propeller disk. So descend rates would be pretty fast, and aerodynamic stability not necessarily guaranteed.

In the end you probably have to design the aircraft for it. Might be worth it for applications like sky-diving planes or heli-sking helicopters.

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

#266

Post by masklinn »

walrus01 wrote: post #250
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…

> A modern series hybrid like a Toyota Prius is effectively an electric vehicle and a gas generator (which means it has the same efficiency gains due to regenerative braking). That gets 52 mpg, which is about 493 Wh/km. Wait, does a new prius or something like a hyundai ioniq (also 52-53 mpg) not have the internal combustion engine mechanically coupled to the transmission and drive wheels anymore?

They do, but also don’t, the Prius and the Ioniq are series-parallel hybrid so the ICE plugs into a power splitter which can feed into both the mechanical transmission and a generator.

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

#267

Post by rimliu »

walrus01 wrote: post #250
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…

> A modern series hybrid like a Toyota Prius is effectively an electric vehicle and a gas generator (which means it has the same efficiency gains due to regenerative braking). That gets 52 mpg, which is about 493 Wh/km. Wait, does a new prius or something like a hyundai ioniq (also 52-53 mpg) not have the internal combustion engine mechanically coupled to the transmission and drive wheels anymore?

I've got Civic e:hev, which has kind of similar setup. ICE does drive wheels in some situations (high speed, much power required), but mostly is just EV. It does not even have a gearbox, so there is only direct coupling from ICE to the wheels that can be engaged or disengaged (this is done automatically, you have no manual control over this).

I really like this setup, because it gives economy, but also a range and I don't need to worry about where to charge the car.

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

#268

Post by peoplefromibiza »

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…

> A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg

That's not very good, my LPG car runs on average around 25km/l and around 30km/l on gas, albeit being a 10 years old model.

Modern diesel cars run on average at over 20km/l, the Citroen C3 does ~30km/l.

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

#269

Post by 2rsf »

TylerE wrote: post #135
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…

Regen braking will do that. I suspect it’d be a much closer competition at, say, 80mph stead state.

Regen braking is 60-70% efficient, and it also limits your ability to free roll (let go of the gas and let the car use its inertia) for example going downhill or on level highways. Polestar for example recommends to lower the OPD sensitivity on highways to increase efficiency.

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

#270

Post by masklinn »

Aromasin wrote: post #213
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 also does for some God awful reason (especially infuriating considering it's sold by the litre at the petrol station). In the United States and some other countries, a gallon is equal to 128 fluid ounces or 3.785 liters. Meanwhile, in the United Kingdom and some Commonwealth countries, a gallon is equal to 160 fluid ounces or 4.546 liters.

In fairness the fluid ounces are also different, an Imperial (english) fluid ounce is 28.41306mL, while a US Customary fl oz is 29.5735mL. So the Imperial floz is 96% the US customary, not enough to account for having 25% more of them in a gallon, but it does lead to the Imperial gallon only being 20% larger than the customary gallon.

But wait there’s more! The US also has the “food labelling” fluid ounce which is not the customary one, instead it’s exactly 30mL.

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