Cybertruck will be 800V

[AlanSubie4Life]

Ahhh. All those promises on Battery Day…. What happened?

The good news is that this does seem to be the biggest issue with Cybertruck. It might be possible to fix this, depending on how badly the 4680s are underperforming (the more they are underperforming, the better).

Density on the Model Y was awful:

Per cell 4680:2170:

5.48x volume
5.7x weight (355g vs. 62g)
4.4x energy (67.5kWh 92s9p vs. 82kWh 96s46p)

Hopefully that huge miss on energy still exists on Cybertruck currently. Improve by 14% to 5x and all is well with the truck, exactly as designed. (Would have 147kWh, 4% more than Max pack Rivian, and 390 miles range (far exceeding Rivian Max pack with AT tires).

 

[Tam]

What I would love to know is why they are installing V4 chargers with V3 cabinets. Are the V4 cabinets that far behind and will they go back and change the V4 charger/V3 cabinets already installed (sounds expensive)?

[conjecture] The 350kW is a C-rating limitation of the V2 4680's and hopefully we will see that increased to 500kW in V3. This could also increase the power of the CT closer to Plaid and most importantly V3 needs to increase the energy density and range. Almost embarrassing that V2 is at best only on par with 2170's. If the original expectations were released the CT would have closer to >375 mile range.

View attachment 995975

I suspect 1000V hardware is more expensive than current 400V ones.

There are many V2 and urban Superchargers but Tesla don't convert most of them. Tesla just adds more V3 on top.

I suspect that will be the same with 400V V4. Tesla will add 1000V V4 to expand the number and not to retrofit to keep the same number.

 

[TessP100D]

The good news is that this does seem to be the biggest issue with Cybertruck. It might be possible to fix this, depending on how badly the 4680s are underperforming (the more they are underperforming, the better).

Density on the Model Y was awful:

Per cell 4680:2170:

5.48x volume
5.7x weight (355g vs. 62g)
4.4x energy (67.5kWh 92s9p vs. 82kWh 96s46p)

Hopefully that huge miss on energy still exists on Cybertruck currently. Improve by 14% to 5x and all is well with the truck, exactly as designed. (Would have 147kWh, 4% more than Max pack Rivian, and 390 miles range (far exceeding Rivian Max pack with AT tires).

I agree with 100%. Sometime in the future, somebody will become the next billionaire when they solve the mystery. tesla failed.

 

[Mrbrock]

When it comes to the Cybertruck, what is your source for the +40% figure?

The only information I've seen on the Cybertruck's charging rate from any kind of real source is from Tesla's VP of Engineering who said that the Cybertruck would charge from 15% to 85% in 18 to 20 minutes on a V4 Supercharger that supports 350kW charging. Trying to figure out what that means on a V3 Supercharger would require making a lot of assumptions. Hopefully someone like Kyle Conner gets ahold of a Cybertruck pretty soon, runs it through its paces, and can give us real world numbers.

From the post by gtx I quoted in my reply to gtx.

“Y’all… 136 miles out of 340 is 40%. Adding 40% in 15 minutes is not indicative of a great charging curve or c-rate. Pretty much every other battery type Tesla offers adds 50% in 15 minutes. Heck, even my Model 3 RWD standard range adds 50% or 136 miles in 15 minutes, and it’s one of the slowest charging Tesla models.”

50% x 80kwh = 40kwh
40% x 130kwh = 52kwh

40kWh in 15 min is less than 52kwh in 15 minutes. That is what I was pointing out. Gtx suggests the CT c-rate based on %/min is worse than other Tesla batteries. I was pointing out % doesn’t work, you have to use actual energy which is how you get c-rate.

 

[JulienW]

I read that there are 1366 4680's in the CT. So if it is 123kWh usable battery it is likely almost 130kWh total. This would make the V2 4680's about 95Wh.

 

[AlanSubie4Life]

I read that there are 1366 4680's in the CT. So if it is 123kWh usable battery it is likely almost 130kWh total. This would make the V2 4680's about 95Wh.

As has been widely reported here, if the 42.9kWh/100mi and 340 mile range is correct, 129kWh is the pack capacity (this is the same as 123kWh, the lower number being the "usable" amount to 0% - of course 129kWh is also usable, but in a different way). Supporting evidence is the 123kWh number reported widely by "official" reviewers - so that lines up, as 123kWh/0.955 = 128.8kWh.

However 1366 4680s seems like it has to be incorrect (at least if that is the number of non-dummy cells). 683 is prime. That's no good.

There are discussions and links to discussions elsewhere on this topic. Not sure if anyone has found the data needed to give the correct answer yet.

82Wh/cell is the number to beat at the moment (Model Y AWD). Not a high bar.

 

[GregD60]

What I would love to know is why they are installing V4 chargers with V3 cabinets. Are the V4 cabinets that far behind and will they go back and change the V4 charger/V3 cabinets already installed (sounds expensive)?

[conjecture] The 350kW is a C-rating limitation of the V2 4680's and hopefully we will see that increased to 500kW in V3. This could also increase the power of the CT closer to Plaid and most importantly V3 needs to increase the energy density and range. Almost embarrassing that V2 is at best only on par with 2170's. If the original expectations were released the CT would have closer to >375 mile range.

View attachment 995975

Regarding the charging cabinets, that's something that I wish Tesla would tell us instead of keep it a secret. And I think your conjecture about the 4680 batteries in the CT makes a lot of sense. At least the V2 gen of the 4680 batteries seems to be more or less on a par with the 2170s, but they're certainly not up to the level Tesla told us about on Battery Day 4 years ago. We're not seeing the 54% range increase they hyped; that alone would probably have given the CT a 500 mile range without a range extender. Hopefully, Tesla is at least starting to see some cost savings with the 4680s and will continue to improve them. Maybe in 2 to 3 years, we'll see a CT with the extra range, but I'm not holding my breath.

 

[Mrbrock]

Regarding the charging cabinets, that's something that I wish Tesla would tell us instead of keep it a secret. And I think your conjecture about the 4680 batteries in the CT makes a lot of sense. At least the V2 gen of the 4680 batteries seems to be more or less on a par with the 2170s, but they're certainly not up to the level Tesla told us about on Battery Day 4 years ago. We're not seeing the 54% range increase they hyped; that alone would probably have given the CT a 500 mile range without a range extender. Hopefully, Tesla is at least starting to see some cost savings with the 4680s and will continue to improve them. Maybe in 2 to 3 years, we'll see a CT with the extra range, but I'm not holding my breath.

The change from V2 to V3 to V4 doesnt necessarily need to have a change in architecture. We saw that with V2 to V3 but maybe the V3 architecture is scalable and the reason they don't have anything higher than 250kw is there isn't the demand for 350kw charging. The only vehicle that can handle that is the Cybertruck because all CCS cars through Magic Dock are limited to 150kw or below (which is likely by design so Tesla still has a selling point now that its network wont be exclusive). Once CT is more out in the real world, I imagine we will see "V4" cabinets which may just be changed internals with updated ratings plaques. The main switch with V4 posts is the longer cable, built in Magic Dock and payment screen to allow them to meet government requirements for funding, not necessarily the future higher speed capacity. The CT handles the 400V to 800V switch internally for charging so Tesla just needs to have 800V capable switchgear and inverters but the truck can still charge quickly at 250kw 400V.

 

[JulienW]

....However 1366 4680s seems like it has to be incorrect (at least if that is the number of non-dummy cells). 683 is prime. That's no good.....

Yea it doesn't add (or divide) up since the pack must be made of 2 split ½ packs for the serial or parallel charging. And I think it takes 96 cells or parallel cell bricks in series to get a nominal 400V.

 

[AlanSubie4Life]

And I think it takes 96 cells or parallel cell bricks in series to get a nominal 400V.

There are a number of options here. There is also terminology.

Tesla calls 96s 350V (or 360V, don’t remember, doesn’t matter). Max 403V
110s is 400V. (Max 462V)
Model Y 4680 is 92s

So not clear how many in series on each half there will be for Cybertruck. If we knew it would REALLY narrow down the possible number of cells.

1344 would be 2x96x7. However, old v1 density was 81.2Wh/cell. New is supposedly about 89.5Wh. Is only 120kWh. Too small, even if the pack is only 123kWh (I think it is 129kWh (aka 123kWh “usable”) but I definitely could be wrong).

But there are considerations for number of modules and if they are all the same (they were not for Model 3).
And wiring up of the bandoliers. As I recall (would have to go look at the post): In Model Y 4680 they had bandoliers of 69 cells, three bandoliers per module, took sets of three cells at a time from a bandolier, so each module was 9px23s. I guess the cooling snake went down each bandolier (don’t remember, would need to look)?

What is bandolier size here? No idea. Are they going to try to wire similarly to Model Y?

Anyway with a couple clues could probably work it out but you have to go to the posts elsewhere that look at dimensions, etc.

I’m just going to not worry about it until we actually have capacity numbers. I assume the pack will look similar in many respects to Model Y.

It could be 2x6x120. 1440 cells (no idea where 1366 would come from though so this really seems unlikely as a “simple mistake” in quoted cell count). 1440*0.0895 = 128.8kWh

Similar to Y but six thinner modules per pack half. Would be similar width as model Y pack - makes no sense.(Can’t re-use four-module BMS then…)

Each module 6x20. Total length 40 cells (physically it would be longer than this since assuming groupings of 3 cells at a time). I think this is far too long. Bandoliers of 60 cells. Would be 74% longer (2*20/23) than Model Y - probably too long.

Anyway just an example (which is wrong) of considerations. Has to fit, use BMS maybe, have series number divisible by number of modules (assuming identical modules), etc.

 

[JulienW]

Here is one of the 3 people that got to review the CT and he also says 1366.

âï¸ 1366

33 seconds · Clipped by William Julien · Original video "Exclusive 2024 Tesla Cybertruck Full Review & Drag Race w R1T & Hummer â Jason Cammisa on the ICONS...

youtube.com

 

[AlanSubie4Life]

Here is one of the 3 people that got to review the CT and he also says 1366.

âï¸ 1366

33 seconds · Clipped by William Julien · Original video "Exclusive 2024 Tesla Cybertruck Full Review & Drag Race w R1T & Hummer â Jason Cammisa on the ICONS...

youtube.com

Yeah it has been speculated that maybe the 48V system has these cells too and those are counted?
Hard to know.

If you assume 22 (2s11p) for “48V”…then…

1344 works ok:

Could be 2 x 112s6p, perhaps 8 modules of 14s6p for each of the 2 halves? Might be too wide (33% wider than Model Y) though.

Means ok density if actually 123kWh, not 129kWh - would be 91.5Wh per cell. About what is expected for version 2 4680.

Anyway we just have to wait.

 

[JulienW]

Yeah it has been speculated that maybe the 48V system has these cells too and those are counted?
Hard to know.
If you assume 22 (2s11p) for “48V”…then…

Bet (s) that is it. 48V never crossed my mind. I just assumed the accessories battery was an OEM battery like every other. But of course since this is the first 48V system there are no "off the self" 48V batteries yet and Tesla is likely "building" it out of the 4680's.

Also I think you meant 22 (11s2p).

EDIT: Wouldn't LFP make a better chemistry for an accessory battery?

 

[AlanSubie4Life]

22 (11s2p).

Yes. Typo. This would be 46V max. Seems sort of like 48V, haha. Probably doesn’t really matter what the voltage is as long as it much higher than 12V. Using Tesla’s other definitions, this would be “40V” (96s is “350V,” 110s is “400V”). 2kWh “pack” of about 12kW output, constant, but for a fairly short time (~300A at 40V), very roughly. (Depends on cell specs!)

Obviously other combinations are possible. If 1366 is the correct number for total cells in the vehicle.

All really speculative. I am not sure what type of lithium ion batteries they use in the new “12V” systems. (EDIT: CATL prismatic cells.).

 

[AlanSubie4Life]

EDIT: Wouldn't LFP make a better chemistry for an accessory battery?

Yeah perhaps. Otherwise it needs of be warmed up a lot before charging it, etc. but who knows, maybe it is part of the main pack now…haha. The best part is no part!

It does make sense, sort of. Though I think HV isolation is problematic if you implement that way…

All highly speculative. Not saying I think that is what is going on; just was working through that hypothesis, assuming 1366 is correct. I really have no idea. We’ll have details soon.

 

[Nack]

Bet (s) that is it. 48V never crossed my mind. I just assumed the accessories battery was an OEM battery like every other. But of course since this is the first 48V system there are no "off the self" 48V batteries yet and Tesla is likely "building" it out of the 4680's.

Also I think you meant 22 (11s2p).

EDIT: Wouldn't LFP make a better chemistry for an accessory battery?

Is the cybertruck actually 48V? I thought they decided to go to a standard voltage like the semi.

I think 48V was one of the many things that were an idea that never materialized, but it would be cool if I am wrong.

 

[GregD60]

Is the cybertruck actually 48V? I thought they decided to go to a standard voltage like the semi.

I think 48V was one of the many things that were an idea that never materialized, but it would be cool if I am wrong.

Yes, the Cybertruck has a 48 volt low voltage system. See the picture in post 18 in this thread from the delivery event. Tesla is actually making a big deal about it.

 

[israndy]

It's required for steer-by-wire, all this new tech is really putting a strain on the voltage, so it was time to move up.

 

[Nack]

Yes, the Cybertruck has a 48 volt low voltage system. See the picture in post 18 in this thread from the delivery event. Tesla is actually making a big deal about it.

Thank you for that. From what I had seen they did not include it but I must have misunderstood or it was incorrect information.

Do you know if it has a 12V system at all? Curious if it has no 12V bus, or if it has 12,48, and 800V.

Either way, more accessories at 48V is nice. Hopefully they have eliminated the 12V bus and run everything off the 48V to kickstart the transition.

 

[Mrbrock]

Thank you for that. From what I had seen they did not include it but I must have misunderstood or it was incorrect information.

Do you know if it has a 12V system at all? Curious if it has no 12V bus, or if it has 12,48, and 800V.

Either way, more accessories at 48V is nice. Hopefully they have eliminated the 12V bus and run everything off the 48V to kickstart the transition.

How am I going to light my cigarettes with no 12v lighter plug?