A look at the new Tesla cells

Any reliable updates on the 21700 Tesla cell specs?

electro wrks said:

As others have pointed out, things don't pencil out for the new Semi and R2 to be using today's battery technology.

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Yeh, I get that but was more interested in the Model 3 battery and how we might use the salvage

brian_ said:

Since Model 3 modules built of the 2170 cells are presumably superior to the 18650's in current production models, my guess is that modules which you salvage from Model 3's after they go into actual production will be the same as what will be used in the Semi (and presumably Roadster 2). Or at least the cells in them will be the same.

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The Tesla Model 3 battery capacities announced by Elon Musk suggest that the 2170 is 'simply' a repackaging and cost reduction exercise. Clearly a 200kWh battery will not fit in the Roadster 2 without some major improvements in energy density (at least x2). It's hard to know whether Tesla can deliver this in two years, but given Musk has never met a date I guess two years could turn into five and then maybe it's possible

Solarsail said:

The 3.4Ah capacity is for a 18650. Now since the 2170 is 1.466x the volume of the 18650, one would expect the proportional capacity for the 2170 to be 4.98Ah. But if the capacity is confirmed at 4.6Ah, then that is a step backward! (Note that the 'chemically usable' volume proportion of the 2170 is actually higher - about 1.5x, which implies a capacity of 5.1Ah.)

The T3 LR pack is estimated at 78 kWh nominal (and 74 kWh usable). 78 / 4416 / 3.6 = 4.9Ah -- which I believe is more likely (than 4.6Ah).

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Thanks, that makes a lot more sense

Karter2 said:

I doubt Musk is in any rush to alter/improve the cell performance just yet.

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I agree... hard to imagine how we get from here to a 200kWh Roadster 2 battery in two years

aeroscott said:

Elon said...

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I think that's the problem

All of this would be so much more believable if Tesla actually demonstrated a significant improvement in capacity rather than a change in packaging which, while important, cannot deliver the 200kWh Roadster 2 battery

Duncan said:

Musk has a history of under promising and over delivering on everything except time frames

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Many examples where that's untrue... one obvious example is the Roadster 3.0 upgrade, the majority of which never happened, and the one that did (battery replacement) looks like a $30,000 disaster

https://teslamotorsclub.com/tmc/posts/2402353/

aeroscott said:

Energy density is a given with time at this point.

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Do you believe that Tesla will deliver a 200kWh battery, that occupies less volume than today's Model S battery, in two years time?

aeroscott said:

Could just be a S with 2 100Kwh packs.

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Most people have concluded that the Roadster prototype does not have enough height for a double layer battery based on 18650/2170 cells... some people reported "sitting high up" during the test drive so maybe some batteries are under the seats but IMO this car does not have enough space for 200kWh today.

aeroscott said:

If it's a little heavy so what , add more power.

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How much power do you need *today* to get a 200kWh battery, three motors, and four people to 60mph in 1.9 seconds, 100mph in 4.2 seconds, and then top out above 250mph without (presumably) shifting?

With enough time and resources almost anything is possible but I think this car requires a step change in battery technology that Tesla may or may not have achieved. Personally I'll be keeping my cash in my pocket, especially until we see the reality of Model 3 production

electro wrks said:

If I'm not mistaken, the R2 has motor based torque vectoring. This implies symmetry, side to side, for the two motors and gear reduction boxes in the back.

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Multiple articles have stated that the Roadster has torque vectoring... I'm not sure what the original source of this is but suspect it will be required to get such a heavy car around corners.