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samroy92

samroy92

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I've seen quite a bit of wrong info here about C rate, limits and so on

I actually went and did the math using real data that we have from current 4680 cells
You say 4680's could achieve 6C rate, what real world data do you have to support that?
Tesla Cybertruck Cybertruck 1000V Architecture + V4 Supercharging Confirmed!! ⚡️ "It's Going to be Used for Cybertruck Too" - Elon Musk 1670041340763


You can try charging these cells at 6C and they will degrade very fast, even with the major advancements in cell chemistry and tabless. The internal resistance goes down but the volume of the cell is much larger:
Tesla Cybertruck Cybertruck 1000V Architecture + V4 Supercharging Confirmed!! ⚡️ "It's Going to be Used for Cybertruck Too" - Elon Musk 1670041651561
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GnarlyDudeLive

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You say 4680's could achieve 6C rate, what real world data do you have to support that?
1670041340763.png


You can try charging these cells at 6C and they will degrade very fast, even with the major advancements in cell chemistry and tabless. The internal resistance goes down but the volume of the cell is much larger:
1670041651561.png
Take a peak at his reddit thread, he provided the data there and even in downloadable form.
 
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Take a peak at his reddit thread, he provided the data there and even in downloadable form.
I looked at the sources, there is no mention or reference to C-Rate Cycle life data. This is very far fetched saying that current S/X can achieve 6C 600kW charging - it's totally possible but the cell will die FAST:

Tesla Cybertruck Cybertruck 1000V Architecture + V4 Supercharging Confirmed!! ⚡️ "It's Going to be Used for Cybertruck Too" - Elon Musk 1670042093715


@GhostAndSkater not trying to pile on you here but you have to provide some data to back up your claim that a 4680 can hit C-Rate 6C without massively damaging the cell. Cell cycle data at 6C
 

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No, that's not how it works. The disengagement is so that coasting motors don't induce eddy currents, which will cause resistance on the drive axels. Has nothing to do with friction. The motors are essentially frictionless.
I don't think free-wheeling motors are frictionless. There must be somewhat significant drag due to the gear reduction having to spin the rotors up to somewhere around 12X-14X the speed of the axles. I'm assuming the Semi uses a lower gearing than the Model S since there is no need to go 200 mph in a semi but the additional torque at low speed would be useful when loaded and starting on a hill.

The eddy currents just add to the drag caused by friction of the gear reduction unit.
 


flowerlandfilms

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Not to bore people with Antipodean problems, but this raises all manner of questions for non Americans.

Most of the world has adopted CCS for better or for worse, not looking to start the debate on that, but Tesla thanks to the split standards is already forced to manufacture at least two connectors, NACS for the US and CCS for global use.

CharIN, the group behind CCS, has since 2018 been preparing MCS, their version of megawatt charging. It has a different shape to CCS and is not backwards compatible, I don't think this spec is finished or in use yet, but Tesla in the future will now have to make 3 connectors at least.
So then, what port will we get for the Cybertruck in the meantime?

Do we get CCS standard which limits our ability to use these new high power features, permanently janking our abilities compared to american trucks?

Or does CCS have expanded capability built into the spec that Tesla can utilise, even if they do so before CharIN has implemented those new design standards? There is a lot of talk in CharIN design documents about "proposed specs" and "in future we may consider" but Tesla is moving faster than that.

Does Tesla give us V4 capability via a NACS V4 port whatever that may look like in an attempt to beat MCS to market?

They can't give us an MCS port on the CyberTruck because then we couldn't charge at any existing stations.

Disclaimer: I am not an electrical engineer, and good information is difficult to sift through online.

Double Disclaimer: I am not as panicked as this post may make me sound, just curious and ill informed.
 

GnarlyDudeLive

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Not to bore people with Antipodean problems, but this raises all manner of questions for non Americans.

Most of the world has adopted CCS for better or for worse, not looking to start the debate on that, but Tesla thanks to the split standards is already forced to manufacture at least two connectors, NACS for the US and CCS for global use.

CharIN, the group behind CCS, has since 2018 been preparing MCS, their version of megawatt charging. It has a different shape to CCS and is not backwards compatible, I don't think this spec is finished or in use yet, but Tesla in the future will now have to make 3 connectors at least.
So then, what port will we get for the Cybertruck in the meantime?

Do we get CCS standard which limits our ability to use these new high power features, permanently janking our abilities compared to american trucks?

Or does CCS have expanded capability built into the spec that Tesla can utilise, even if they do so before CharIN has implemented those new design standards? There is a lot of talk in CharIN design documents about "proposed specs" and "in future we may consider" but Tesla is moving faster than that.

Does Tesla give us V4 capability via a NACS V4 port whatever that may look like in an attempt to beat MCS to market?

They can't give us an MCS port on the CyberTruck because then we couldn't charge at any existing stations.

Disclaimer: I am not an electrical engineer, and good information is difficult to sift through online.

Double Disclaimer: I am not as panicked as this post may make me sound, just curious and ill informed.
I mean Elon indicated right from the start that the initial release of the CT was specifically for the US market. I feel for the others and I am sure in due time non American markets will get a revised CT as well outside of US purchased and privately shipped. Note: the NACS port can be adopted by anyone now so there is hope outside of just Tesla provided chargers as well.
 

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The wall connector itself costs more than a placeholder outlet.

-Crissa
At $400 for the Wall Connector and $230 for the Mobile Connector and another $100 for an industrial grade NEMA 14-50 outlet the difference for the superior solution is only $70. If the install is 50 feet from the panel you will pay that much just for the extra conductor that the outlet requires bringing the total cost to parity.

Even if the Wall Connector costs a few bucks more it's worth it for the thicker, more durable 24 foot cable, more power and fewer potential points of failure. It's just more robust and satisfying to use and has built-in cable management. There is also the option to piggyback one or more additional Wall Connectors on the same breaker so you can do intelligent load sharing with two or more EV's.

Before I knew better I thought the Mobile Connector would be a lot cheaper but it turns out it's basically a wash once all is considered. Using a NEMA 14-50 as a placeholder for a future Wall Connector is not a great idea and would end up costing even more in the end.
 


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Just realized! we’ve been focused on the wrong things!
Was just watching a documentary and realized all exoskeletons shed to grow bigger!
That’s the technology band wagon Elon is talking about. The cybertruck will naturally shed and grow bigger as you drive it further!
- how did we miss that people!
 

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I looked at the sources, there is no mention or reference to C-Rate Cycle life data. This is very far fetched saying that current S/X can achieve 6C 600kW charging - it's totally possible but the cell will die FAST:
Read the article in whole rather than cherry picking and it covers both max rates as well rates Tesla likely has placed based on safety/longevity of the battery. Thermal management is key here as well, and again Tesla plays on the safe side until it gets more days/months/years or miles for that matter of data. This means if the data comes back looking good or better than expected, Tesla has the option to software push things like unlocking higher charging rates. Likewise they could lower it as well if necessary though I tend to believe they play it safe enough from the start to not have to do that as that would be a public relations nightmare.
 

firsttruck

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------------------------------

Regenerative braking: A closer look at the methods and limits of regen
Posted October 3, 2018
by Jeffrey Jenkins
https://chargedevs.com/features/reg...oser-look-at-the-methods-and-limits-of-regen/

.....
There are some limits to regen braking. For starters, it can only recapture the energy used to accelerate the vehicle or climb an incline, minus some inevitable losses. Speaking of which, the energy recaptured by regen has to go through the full conversion process – from chemical to electrical to mechanical to road – twice. Typical efficiencies for each major step in this process are 99% for lithium chemistry batteries, 96-98% for inverters, 80-95% for motors (though this can drop much lower, especially at either extreme of the power range), 95% for hypoid gear differentials (which tends to get overlooked) and, finally, 85-95% for tires. Even taking the best-case values for each figure, that comes out to an overall efficiency from battery to road of 83%, and a round-trip efficiency of 69%; in other words, you can’t always regen brake your way to longer range.

Another, more obvious, limit to regen braking is tire adhesion. This is less of an issue in front-wheel drive EVs, but applying too much braking torque to the rear wheels in rear- or all-wheel drive EVs (especially motorcycles) can, shall we say, make for an exciting driving experience. This is due to the phenomenon called “load transfer,” in which the center of mass on any wheeled vehicle shifts due to acceleration or deceleration forces, and this shift is proportional to the height of the center of mass above ground and inversely proportional to the wheelbase (note that in a 4-wheel vehicle, load transfer can occur front to back, as during acceleration and braking, or side to side, as during turning). Load transfer can be exacerbated by weight transfer, which is the same effect except caused by suspension travel or actual shifting of liquids, cargo, etc, in the vehicle. Together these phenomena lower the weight over the rear wheels during braking, making them less effective at transferring force without skidding.

------------------------------
 

RVAC

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Yes I am under that impression because I read the NACS document.
So you think they will make 2 1MW chargers that do exactly the same thing but have different ports for no reason.
Tesla is also part of the CharIN MCS standard, maybe that will only be for Semi in Europe but from the few photos that we've seen US Semi does not appear to use the NACS connector.



You seem to be under the impression that a V4 SuperCharger is the same as a MegaCharger for the Semi. I do not share this view.

The newly revealed liquid-cooled cable will be used on the V4 SC, as well as the MC, but each will have different charge ports for different purposes.
I think so too, also it would be very odd to have passenger vehicles like CT fighting with Semi's for charging spots.

Not to bore people with Antipodean problems, but this raises all manner of questions for non Americans.

Most of the world has adopted CCS for better or for worse, not looking to start the debate on that, but Tesla thanks to the split standards is already forced to manufacture at least two connectors, NACS for the US and CCS for global use.

CharIN, the group behind CCS, has since 2018 been preparing MCS, their version of megawatt charging. It has a different shape to CCS and is not backwards compatible, I don't think this spec is finished or in use yet, but Tesla in the future will now have to make 3 connectors at least.
So then, what port will we get for the Cybertruck in the meantime?

Do we get CCS standard which limits our ability to use these new high power features, permanently janking our abilities compared to american trucks?

Or does CCS have expanded capability built into the spec that Tesla can utilise, even if they do so before CharIN has implemented those new design standards? There is a lot of talk in CharIN design documents about "proposed specs" and "in future we may consider" but Tesla is moving faster than that.

Does Tesla give us V4 capability via a NACS V4 port whatever that may look like in an attempt to beat MCS to market?

They can't give us an MCS port on the CyberTruck because then we couldn't charge at any existing stations.

Disclaimer: I am not an electrical engineer, and good information is difficult to sift through online.

Double Disclaimer: I am not as panicked as this post may make me sound, just curious and ill informed.
That the whole world uses it is a bit of a myth, US uses CCS1 which is not the same as European CCS2, China uses their own connector which is GB/T.

My guess is that Semi uses MCS but CT will use NACS.
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