CT end of life

[Dids]

Sorry I think we might be talking past eachother. Let me try again.

There are two distinct sides of the range "coin" conversation. One is vehicle energy consumption, or rate of work, the other is available energy capacity to do said work.

So given these two distinct sides, we can say that on a EV the energy "consumption", or work, that is caused by weight is less pronounced as it is on a ICE. Thats fine.

But, range is a consequence of energy vs work, and in the case of a ICE, its fuel energy storage "battery" is simply some 5x the "usable size" of a CT TM battery in kWh to the wheels. So even if the ICE had twice the consumption of the EV because of the load* the ICE would still have 2.5times the range.

So effectively EVs have less weight induced consumption (mostly because of regen), but ICE still have much more available energy.

(*load being weight, and weight having the effect of increasing rolling resistance, which is only part of the total drag according to the previously posted graph.)

BTW ICE typically have maximum Carnot efficiency at max RPM/Power. So that would be a correct assumption but not my point here.

I hear you but do respectfully disagree. I did know what you were saying but took pains to point out that what you are saying also means that a ln EV is less effected by a change in load. It does not matter if that change is aerodynamic or weight etc. My disagreement and attempt to lead you to a physical truth is what matters is energy conversion rate. I am trying to convince you that energy density does not matter, that it doesn't change and therefore is irrelevant.
I am trying to make the point that the increase rate of energy consumption as work increases is the most important factor in this problem and that you are wrong to assume that an EV is effected more by an increase in load.
Everyone knows that a diesel is effected less by an increase in load than a gas engine. It is unfortunate that some engineers think this is due to energy density of the fuel. It is not. It is purely a function of converstion by the powerplant. A diesel has a higher torque component of the power and therefore experiences a lower rate of increase of energy required as load increases, an EV has an even higher torque component of power. It will experience an even lower rate increase of energy required as load increases. It doesn't matter if that load is aero or weight.

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[Ogre]

No matter how far I coast, my ICE engine will never put gasoline back in my tank

They don’t come to your house and fill your gas tank while you sleep either.

 

[Ogre]

They did put ‘+’ symbols after all the range estimates. It is hard to imagine Tesla bothering to make such a claim if they weren’t pretty certain that they would be somewhat over those numbers. And that was in 2019. Recent reports from credible sources (Dahn and Straubel) tell us that the total number of cycles is already up and that the degradation is already going down.

Yeah, I think the cells they put into that Cybertruck will be a lot better than the cells they put into the Model S 8-10 years ago.

But for the moment the only cells we have with long term data are those 8-10 year old Model Ss.

 

[Crissa]

The increase in load having a different effect is two-fold:

One is that ICE engines have a narrow optimal range. If you slide out of it, you lose efficiency. EVs have a much, much broader optimal range. My Zero has nearly the same efficiency without any gearing from 0 to 100 (and I have gotten it to 98).

Second is that electrics have a heavy battery (traditionally) and so adding the same load is not the same change in gross weight. If the ICE version weighed 2000 lbs and you add 200, you're increasing the total mass by 10%. But the EV had a 1000 lbs in battery so 200 lbs only changed to the gross weight by 6.7%. So the change in efficiency is less.

-Crissa

 

[swengl]

I see a lot of folks talking about swapping out the battery pack on a CT at some point, years down the road. With the pack being truly structural, will it be possible to swap out the 4680 cells? In the non-structural packs, the battery pack (which includes the cooling system, the battery modules (made up of the cells, the thermal management system, the battery management system), the HV bus barand other components and can be dropped out fairly easily, but a structural "pack" is actually the cells being glued in place into the honeycomb which is glued to the floor of the vehicle and the outside plate. It seems that once in place, it will be very difficult to disassemble the structural pack to replace the cells.

 

[Jhodgesatmb]

I see a lot of folks talking about swapping out the battery pack on a CT at some point, years down the road. With the pack being truly structural, will it be possible to swap out the 4680 cells? In the non-structural packs, the battery pack (which includes the cooling system, the battery modules (made up of the cells, the thermal management system, the battery management system), the HV bus barand other components and can be dropped out fairly easily, but a structural "pack" is actually the cells being glued in place into the honeycomb which is glued to the floor of the vehicle and the outside plate. It seems that once in place, it will be very difficult to disassemble the structural pack to replace the cells.

Have you seen the videos they made of the Model Y structural battery packs being installed (take a look at the Cyber Rodeo video)? They mount the seats and raise the whole thing into the car. It ‘looks’ like they could take them out pretty easily. Maybe the CT will be similar…

 

[Crissa]

Have you seen the videos they made of the Model Y structural battery packs being installed (take a look at the Cyber Rodeo video)? They mount the seats and raise the whole thing into the car. It ‘looks’ like they could take them out pretty easily. Maybe the CT will be similar…

Exactly.

The cells won't be swapped out, but the entire component of the body. Bolted on, welded in, just like any other piece.

A major surgery to be sure.

-Crissa

 

[charliemagpie]

I somehow recall advertised 500+ range

but now , looking at the updated Cybertruck page (in AU) it says UP TO 500

Was I wrong, or has it changed ?

 

[Tinker71]

I somehow recall advertised 500+ range

but now , looking at the updated Cybertruck page (in AU) it says UP TO 500

Was I wrong, or has it changed ?

That is a change. The tire selection will play a big role.

 

[SpaceYooper]

I somehow recall advertised 500+ range

but now , looking at the updated Cybertruck page (in AU) it says UP TO 500

Was I wrong, or has it changed ?

Careful...you might start an argument. I've been down this road. Some people here think "up to 500" and "500+" means the same thing.

 

[DMC-81]

I tend to I keep vehicles a long time, and I expect to do the same with the CT. I'll probably replace the battery in 10 to 15 years, or whenever the range gets inconvenient.

 

[CyberGus]

While some Tesla packs are easier to service than others, none are intended to be. Even Tesla will not attempt it, as damaged packs only get replaced.

The early Model S cars are now old enough to be out of warranty, some with faulty packs. There are stories of people picking up such cars for cheap and having the packs replaced.

For me, one of the prime benefits of EV ownership is low maintenance. By the time my CT needs a new pack, I will probably opt to replace the whole vehicle.

 

[JBee]

I hear you but do respectfully disagree. I did know what you were saying but took pains to point out that what you are saying also means that a ln EV is less effected by a change in load. It does not matter if that change is aerodynamic or weight etc. My disagreement and attempt to lead you to a physical truth is what matters is energy conversion rate. I am trying to convince you that energy density does not matter, that it doesn't change and therefore is irrelevant.
I am trying to make the point that the increase rate of energy consumption as work increases is the most important factor in this problem and that you are wrong to assume that an EV is effected more by an increase in load.
Everyone knows that a diesel is effected less by an increase in load than a gas engine. It is unfortunate that some engineers think this is due to energy density of the fuel. It is not. It is purely a function of converstion by the powerplant. A diesel has a higher torque component of the power and therefore experiences a lower rate of increase of energy required as load increases, an EV has an even higher torque component of power. It will experience an even lower rate increase of energy required as load increases. It doesn't matter if that load is aero or weight.

Um ok. So now you are saying that it's because of the electric motor torque that a EV uses less energy with increased weight? Are you also saying that an a ICE has worse range than a EV, or that a diesel has more torque, and has better range because of that?

This is confusing on multiple levels. To motivate any vehicle you require torque to change velocity, and power to maintain the torque, velocity and acceleration. Note torque does not move, it is a force measured in "Nm" (newton meters), which is without a time component. Hence Nm/s = watt which is power. Accordingly, power is what does work, as torque cannot consume energy without time.

So the primary cause for energy consumption in all vehicles is the power required to maintain velocity against drag forces. Further, an ICE, EV or elves on treadmills need to produce this power to overcome drag. In either case a ICE Nm or elve foot pounds, they all have to create the same amount of torque or force, to motivate the vehicle.

Don't forget that we need to measure all these at the point of intersection of these forces, being the contact patch of the wheel on the ground. At that point a ICE can have just as much "torque" as an EV, if not more, because it uses a gearbox to increase torque, using more power at lower rpm, which consumes more energy in that time.

Remember a electric motor might not need a multi stage gearbox, but even a Tesla has a gear reduction to increase torque at the wheel to match the vehicle drag better. This is because a electric motor might have a better torque curve, but it still requires RPM to create power, just like a ICE. The Plaid drivetrain being case in point, running at 30,000RPM, being so fast that centrifugal forces would otherwise expell rotor components and needs a Carbon Fibre wrap to hold it all together.

In fact I doubt a CT would even pull along a 100Hp ICE tractor because of gearing, traction and weight, because it will have less torque at the wheels. Also note that many EVs do not have the high performance electric motors of Tesla EVs, and make generalisations like this problematic.

Either way, EV range is less sensitive to weight increases because of their ability to regenerate energy, but ICE still have greater range because of their superior fuel energy density.

 

[JBee]

I somehow recall advertised 500+ range

but now , looking at the updated Cybertruck page (in AU) it says UP TO 500

Was I wrong, or has it changed ?

I think it might be because the CT with 4680 cells will now only have one layer of battery pack, instead of potentially two layers.

 

[Cyberman]

For someone smart :

Does the 300 or 500 range versions already allow for the .036 drag co-efficient ?

Does .036 drag co-efficient mean a 36% drop in potential distance a truck could travel without a load ?

I take it that advertising should match the likely use... if it says 500 miles, it should mean with a full working load.

If it travels about 2kwp per mile.. 1000 kw of batteries loaded with 80k lb. How far could empty semi travel with that same 1000kw ?

Or maybe I mis-read. Maybe its 500 miles when empty, and you take off the drag when loaded.

Hmm, I dunno. But I do know the Tesla Semi is rated at 500 miles under a full load.

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