rogbmw
Member
Fun reading this thread....but everything is pure guesswork at this point. Heck...we have not even seen/driven the Beta X yet!
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Tesla Model 3 P+ vs BMW M3?
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- Model 3
Yes that is the BMW logo and it already exists. Thing is Tesla hasn't released the logo or even a rough sketch of the Model 3 yet. Wouldn't it make more sense to write what Tesla says they'll call it instead of making up a logo just for clarity? I know writing three lines sideways looks cool and there are 3 lines and it looks like an E in the old Model E and all. Tesla isn't calling it MIII or MIII or M/// or even M3 rather Model 3 or Model III as some news outlets have written. Tesla so far has simply said Model 3. I put that in bold for emphasis. Anyway, it was just a suggestion but up to you of course.
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strider
Active Member
Read my post #28 again:
Tesla Model 3 P+ vs BMW M3? - Page 3
That is why I think they'll charge $100k. Because they CAN.
Also, why did you leave the power the same for the AWD model? Tesla will use 2 motors to get AWD so depending on battery chemistry and PEM construction it could have double the HP of the base model.
My vote on this is to call it the "Model 3" or abbreviate "TM3" to differentiate from BMW. You'd think Tesla would have thought about this since they claim the BMW 3-series is the target of the TM3. -<whee>-
Red Sage
The Cybernetic Samurai
Yes. Because this is a comparison that JB Straubel himself has made. Specifically, he said that the Tesla Model S 85 achieved a higher capacity using fewer 18650 battery cells as compared to the Tesla Roadster at 53 kWh.
It seems here you are comparing the form factor of the battery packs, not the number of battery cells encased within them. The Model S battery pack is a completely different form factor, designed to at once be a stressed member of the frame once installed, as well as to be readily removable for the sake of battery swaps. Neither of those functions was required or engineered for the Tesla Roadster. The battery pack for the Tesla Model S is purposely overbuilt and armored to minimize intrusion and thermal runaway to be as safe as possible in the event of an accident. It is necessarily heavier because of these engineering concerns, not because of the weight of the battery cells themselves.
The battery cells remain the same size and form factor. They are 18650 cells. I'm pretty sure I've said that I expect the capacity to increase, not the size of the cells to decrease. I'm pretty sure I've said, though perhaps not in this particular conversation, that fewer 18650 cells, with higher capacity, could together in an array, store a higher amount of energy.
stopcrazypp
Well-Known Member
I don't know if Straubel ever said something like that, but if Straubel said something to that effect, he may have been talking about the Model S 60kWh. That one has 14 instead of the 16 modules in the 85kWh, which means 6216 cells in the 60kWh pack. So it has more capacity than the Roadster with fewer cells.
I have been talking about the pack itself, when comparing size not the 18650 cells.
And with new factory build from scratches, who says they have to stick to 18650 form factor?
The individual cells get higher capasity with same weight or lower weight and keeps the capasity.
Voltage on indevidual cells can also be changed the drawback with large changes is time consuming testing.
I do not think Tesla will lower the safety standard on the TM3 compared to the ModelS Pack.
The wrapping will be smaler so less weight, the drawback is less space for cells.
Less cells in serie gives less Voltage, less cells in parallell gives less capasity.
Better batteries with more Wh/kg is the solution.
One importen thing with TM3 they cant take a risk on the battery lifetime or fire risk, when the gold is to sell several 100 000 cars a year.
Tesla would not survive if the batteries died after 2-3 years or other major failures.
TM3 with less than 50kWh as standard and more exlusive 75kWh pack.
sigurdi
And with new factory build from scratches, who says they have to stick to 18650 form factor?
The individual cells get higher capasity with same weight or lower weight and keeps the capasity.
Voltage on indevidual cells can also be changed the drawback with large changes is time consuming testing.
I do not think Tesla will lower the safety standard on the TM3 compared to the ModelS Pack.
The wrapping will be smaler so less weight, the drawback is less space for cells.
Less cells in serie gives less Voltage, less cells in parallell gives less capasity.
Better batteries with more Wh/kg is the solution.
One importen thing with TM3 they cant take a risk on the battery lifetime or fire risk, when the gold is to sell several 100 000 cars a year.
Tesla would not survive if the batteries died after 2-3 years or other major failures.
TM3 with less than 50kWh as standard and more exlusive 75kWh pack.
sigurdi
53kWh with 6831 cells vs 60kWh 6216 cells is a increase of 24.4% (from 2008-2012)
The same progress from 2012 to 2016 (as mentioned before) will give a model S or X a 106kWh battery pack with same size as the 85kWh today.
Not a 135kWh pack that need to be 20% smaler in size.
Hope for a 100kWh pack option in the model X.
sigurdi
The same progress from 2012 to 2016 (as mentioned before) will give a model S or X a 106kWh battery pack with same size as the 85kWh today.
Not a 135kWh pack that need to be 20% smaler in size.
Hope for a 100kWh pack option in the model X.
sigurdi
Red Sage
The Cybernetic Samurai
JB Straubel. Multiple times. He has said that people keep harping about the 18650 form factor and that it doesn't matter. What matters is energy density. He says that for all the various configurations of batteries they have explored, none of them trump their use of an array of 18650 cells. He says there is no need to move to bigger individual battery cells. All evidence points to the superior efficiency of using several smaller batteries instead.
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Oops! Sorry... He definitely said 'something like that'... It was in one of three videos I typically reference. I'll check them again and get back to you guys. My apologies in advance, assuming I misquoted or paraphrased incorrectly.
;-)
I did not say larger cells.
Smal cells is better, but do they ned to be as big as 18650?
Array of smal cells is superior to larger, you can connect them in seies and parallell and build a battery pack with the Voltage and current you need.
If one cell or 10 dies it do not infect the pack.
Pack of large cells, the death of one cell have impackt on the pack.
Smal cells is better, but do they ned to be as big as 18650?
Array of smal cells is superior to larger, you can connect them in seies and parallell and build a battery pack with the Voltage and current you need.
If one cell or 10 dies it do not infect the pack.
Pack of large cells, the death of one cell have impackt on the pack.
stopcrazypp
Well-Known Member
I would be careful about using only the 60kWh for comparison as it appears to use less energy dense cells. The 85kWh has 7104 cells, which means a 46% improvement (using 56kWh for Roadster).53kWh with 6831 cells vs 60kWh 6216 cells is a increase of 24.4% (from 2008-2012)
The same progress from 2012 to 2016 (as mentioned before) will give a model S or X a 106kWh battery pack with same size as the 85kWh today.
Not a 135kWh pack that need to be 20% smaler in size.
Hope for a 100kWh pack option in the model X.
sigurdi
Red Sage
The Cybernetic Samurai
Right now, yes. Tomorrow, maybe not. The 18650 battery cell is a known quantity, studied in depth by JB Straubel for well over a decade. The amount of energy stored, its rate of discharge, its lifespan, its resistance to the elements, its chemistry, volume, weight, and capacity and any variables among them are all fully understood. So the software balancing, electronic control systems, and temperature protections that are designed to work with them are optimized specifically for the variables of the 18650 form factor. All those things would have to be designed again from scratch to work with a different cell size or configuration.
100th Post! :tongue: :wink: :biggrin: :smile:
:smile:Most of the things you mentioned will be changes, when they are getting higher densety by altering the electrolyte, additives or anode catode.
Like when they changes the catode from cobolt - (LiCoO2 roadster) to cobolt- aluminium in Model S.
And Sorry
My mistake, the S60 have 5040 cells, and that gives the same densety as the S85.
The increase from roadster when only using the cellcount and kWh gives 54% increase.
Same speed gives a 130kWh in a model S/X in 2016.
Still do not se 135kWh in TM3
A AWD to be racing - Nope
Maybe in 2020.
sigurdi
Like when they changes the catode from cobolt - (LiCoO2 roadster) to cobolt- aluminium in Model S.
And Sorry
My mistake, the S60 have 5040 cells, and that gives the same densety as the S85.
The increase from roadster when only using the cellcount and kWh gives 54% increase.
Same speed gives a 130kWh in a model S/X in 2016.
Still do not se 135kWh in TM3
A AWD to be racing - Nope
Maybe in 2020.
sigurdi
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Well, they told us yesterday on the conference call that they will not stick to 18650 form factor. The new cells will be about 10% wider and 10% higher(?). Something like 20710 maybe?
I did expected a wider cell, but not taller. Rather I guessed on a shorter cell to make the "surfboard" thinner and give more legroom in the car.
Given the same battery size area (L x W) what will that do to kWh (is this the right term) ? ie a MS 85 would possibly become a 120 ? What are the implications for the Model 3 ? ie. a 20% smaller pack with 20% increase in density ? Could a Model 3 potentially have a 85kWh battery ?
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Red Sage
The Cybernetic Samurai
I was pretty surprised to learn they intend to make any physical changes to the battery cells themselves. I had been under the impression that JB Straubel had vetoed that necessity. He did specifically say they would stay with cylindrical battery cells. I have thought all along that an 85 kWh battery pack would be possible, and that the minimum that would be offered is 60 kWh, for the Tesla Model ☰.
stopcrazypp
Well-Known Member
They have said the optimal size is about twice the size of the current cell. I expect wider but not lower. Lower would make the surface area to volume ratio even worse on the sides (in practical terms only the sides of the cell can be used for heat exchange). The existing 26650 format would match this criteria perfectly.
It seems from the conference call they might even make it taller (which would help heat exchange area).
