ALL CyberTruck discussion

[MP3Mike]

As I said it is not (probably) the actual issue only issue here…the charger may not be able to provide the requested current!

And as been said already, the graph includes the requested and delivered current, and they are the same. (i.e. the Cybertruck received everything it asked for.) The Nxu charger can provide up to 700A of current, it is not the limiting factor.

 

[Daniel in SD]

This is what I'm talking about. The Cybertruck charges much faster at 5% than other Teslas:

It keeps up in mi/hr with the Model S Plaid in the first two minutes of charging.

Charging test — Out of Spec Studios

outofspecstudios.com

To me, the only thing that matters is the TIME to reach 80% from low charge. Get it down to 20m or less and I’m happy because then I can leave. I only have a 2-3 hour bladder so the miles or kwhr charged is not important. After 20m, I’m ready to go unless it’s also a lunch stop.

I would wait for 4680 V3 or hope that they're use the 4680 Model Y charge curve temporarily.

 

[CyberShy]

I’d say that’s because there’s a buffer at the bottom.

 

[AlanSubie4Life]

In the 3rd party 800V charger test, it could and it did provide the current requested.

And as been said already, the graph includes the requested and delivered current, and they are the same.

Right. I was attempting to explain the reason why on other Teslas we see limitations below 5% but not for Cybertruck. Obviously no current limitations here for Cybertruck.

However, limitations due to charger current limits alone (perhaps there are other limitations of the charger?) do not explain the curves on other Teslas (my original random guess). As Daniel shows above, the limitations are far more severe than just a current cap due to very low voltage at low SOC (clearly the voltage does not drop that much).

So we don’t know what the issue is with other Teslas (unless it is actually a charger issue, in which case this could presumably go away on future iterations of 400V chargers).

 

[AlanSubie4Life]

I’d say that’s because there’s a buffer at the bottom.

There is the same buffer on all vehicles.

This problem is practically quite a large problem since it discourages using the lower 10% (4.5% + 5%) of range on road trips (of course really just 5% is discouraged, the rest is already discouraged). Not great. (Rather than arriving at target 1-3%, I try to arrive at 6-8%.)

 

[CyberShy]

There is the same buffer on all vehicles.

This problem is practically quite a large problem since it discourages using the lower 10% (4.5% + 5%) of range on road trips (of course really just 5% is discouraged, the rest is already discouraged). Not great. (Rather than arriving at target 1-3%, I try to arrive at 6-8%.)

Looking at the graph above, the CT graph appears shifted to the left compared to the other graph.

Shifted because of buffer a the bottom is my guess. I could be wrong, but assuming ALL vehicles have the same buffer seems spurious.

 

[GhostSkater]

As I said it is not (probably) the actual issue only issue here…the charger may not be able to provide the requested current!

I think I have all the data needed to calculate open voltage from the full voltage, so we can also plot current/voltage vs SoC

Let me know if that would be useful because I'm a bit short on time

 

[Daniel in SD]

Looking at the graph above, the CT graph appears shifted to the left compared to the other graph.

Shifted because of buffer a the bottom is my guess. I could be wrong, but assuming ALL vehicles have the same buffer seems spurious.

119kWh used at 0%
124kWh when it stopped moving

 

[AlanSubie4Life]

I could be wrong, but assuming ALL vehicles have the same buffer seems spurious.

Go look at the range test by whoever it was for the buffer value for Cybertruck. Easy to see, whatever the value is.

All recent vehicles are 4.5%; I don’t make the rules. As far as I know Cybertruck is the same but I do not know how I know that (see post above; that is how I knew, I just don’t remember anything). Anyway you are making the argument that CT has a buffer and the others do not, or have less, so it does not really matter.

 

[GhostSkater]

My take on the current charging curve is that it's the bare minimum to match other EV trucks, which it does and even surpass depending on your SoC window, while still being ultra conservative while Tesla gathers data and crank it up

It might be that they gain confidence and make it reach the quoted 15-85% in < 20 minutes, or the data gathered might show that this is it for this generation of cells and truck on the road

From all the charging tests I've seen so far in Teslas, it seems that their algorithm is voltage based, so for a given cell temperature and SoC, the voltage is allowed to rise to a given level, which current results in that is more or less irrelevant, provided it's under some hard limits for other components on the battery pack and charger

This matters because a big part of degradation happens with phase changes insides the cell, and high power at the phase change points leads to accelerated damage, so as they gather data and see how much they can push to each of those points, the charge curve can get fatter, or not, as I said above

Another way is letting the cells get hotter, since that lowers the internal resistance and allows for more current for a given SoC before reaching the voltage limit

 

[mongo]

Hmm, so it seems that actual "current" line isn't present, unless it's exactly overlayed by the "target current" line...

My quick mental math shows that the current requested is roughly in line with where the current actually is, so yeah, they didn't bother to show it because it's the same

They overlap with blue on top... mostly...

 

[AlanSubie4Life]

hope that they're use the 4680 Model Y charge curve temporarily.

They're not using the Model Y 4680 charge curve (which peaks over 200kW (don't know exact peak) briefly with a ~68kWh pack) on the peak plateau (more like just a peak for Model Y). Otherwise they'd be at ~400kW or whatever; certainly in excess of the peak here in any case. So maybe there's hope!

It's just software!

 

[EVNow]

It's just software!

I think the main problem with CT range is efficiency. Its going to be a difficult roadtrip vehicle ...

 

[AlanSubie4Life]

I think the main problem with CT range is efficiency.

No, it is the charge rate. Even without the higher speed chargers, even 250kW up to roughly 40%-45% (like most of the other Teslas do equivalently!) would probably make it good enough. But it doesn’t; it craps the bed at 25% and has even steeper declines in charge rate than other vehicles for the critical 25-50% window as well.

The new v4 chargers will 1) take years to be wide enough distribution to be useful and 2) won’t help very much with current pack limits.

 

[GhostSkater]

No, it is the charge rate. Even without the higher speed chargers, even 250kW up to roughly 40%-45% (like most of the other Teslas do equivalently!) would probably make it good enough. But it doesn’t; it craps the bed at 25% and has even steeper declines in charge rate than other vehicles for the critical 25-50% window as well.

The new v4 chargers will 1) take years to be wide enough distribution to be useful and 2) won’t help very much with current pack limits.

Again we go back to the charge times of 20 minutes quoted by Tesla engineering, if it did those, it should also maintains 250 kW up to close to 70%

The lack of true V4 deployments make it seems that Tesla don't plan to vehicles taking advantage of it for a long time, else they would be full pedal on it's installation

Just a refresher of how more or less the curve should look for those charge times

 

[jerry33]

I think the main problem with CT range is efficiency. Its going to be a difficult roadtrip vehicle ...

The efficiency appears to be similar to my 2020 X. Road trips are no problem unless there is a local power outage affecting a Supercharger.

 

[Daniel in SD]

The efficiency appears to be similar to my 2020 X. Road trips are no problem unless there is a local power outage affecting a Supercharger.

Cybertruck has 254mi of range at 70mph vs 331mi for X LR. And that’s with a 20% larger battery. And the charge curve is worse. You’d spend almost twice as much time charging on a Cybertruck roadtrip.

 

[Daniel in SD]

Again we go back to the charge times of 20 minutes quoted by Tesla engineering, if it did those, it should also maintains 250 kW up to close to 70%

The lack of true V4 deployments make it seems that Tesla don't plan to vehicles taking advantage of it for a long time, else they would be full pedal on it's installation

Just a refresher of how more or less the curve should look for those charge times

View attachment 1025255

Yep, only competitors will be able to benefit from V4 for the foreseeable future.

 

[uscbucsfan]

Cybertruck has 254mi of range at 70mph vs 331mi for X LR. And that’s with a 20% larger battery. And the charge curve is worse. You’d spend almost twice as much time charging on a Cybertruck roadtrip.

That was for the refresh X and only had a usable battery of 93 kWh. I was pretty shocked by that testing for the MX to be honest.

 

[Daniel in SD]

That was for the refresh X and only had a usable battery of 93 kWh. I was pretty shocked by that testing for the MX to be honest.

I’m referring to this test. 100kwh battery.

Eggmobiles FTW.