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Discussion Starter · #1 ·
So it's began;

Interesting they are using 18650 rather than 2170 format.


Quoted from Ingineerix:
The Tesla Plaid pack uses 7,920 18650 cells arranged in 5 modules that have an 72P22S arrangement each. (total of 72P110S)
Same BMS system as Model 3/Y.
It is capable of sustained 2300A output at a max voltage of 462V (That's over 1 megawatt!).
Each module is 15 3/8" (390mm) long X 55 1/4" (1404mm) wide X 3" (76mm) high. If you include the coolant manifolds and lines, the width is 57 3/8" (1458mm).
This pack's data obtained from the BMS: Beginning of Life Pack Energy: 99KWh Nominal Energy Remaining: 32KWh Nominal Full Pack Energy: 95KWh Charge Total: 1564.13KWh Discharge Total: 1484.05KWh Present SoC: 34.3% Cell Voltage Min: 3.592V Cell Voltage Max: 3.598V Estimated cell capacity: 12.5Wh or about 3.4Ah. Max cell level discharge is about 32A.
 

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Interesting they are using 18650 rather than 2170 format.
It's interesting that they're also not using the 4680 cells that they have been shouting about so much. ;)

Since everything about the construction is based on the Model 3 design, rather than the original Model S/X, the longer 2170 cells should have fit in height - interleaving both bus plates on the top of the module instead of bus plates alternating top and bottom saves the height needed for the longer cells.

The Tesla Plaid pack uses 7,920 18650 cells arranged in 5 modules that have an 72P22S arrangement each. (total of 72P110S)
22S per module multiplied by 5 modules is 110S overall - a significant increase from the 96S of all 16-module Model S/X packs, but not a big deal. While 96S is by far the most common choice for modern EVs, the Jaguar I-Pace uses 108S, for instance.

85 kWh Model S/X packs have used 74 cell groups (so 96S74P for 7104 cells total) and 100 kWh used 86 cell groups (so 96S86P for 8,256 cells total); this is down to 72P so even with more groups in series the total cell count is down from the previous 100 kWh pack. All 7,920 cells fit in the space previously occupied by 14 of the old modules (7,224 cells) because there is less space lost to gaps around modules.

Each module is 15 3/8" (390mm) long X 55 1/4" (1404mm) wide X 3" (76mm) high. If you include the coolant manifolds and lines, the width is 57 3/8" (1458mm).
The original Model S pack used seven pairs of modules, each pair spanning the width of the pack. The Model 3 uses only 4 modules, each spanning the length of the pack. This is in-between, with each module spanning the width (by itself, instead of a pair).

An interesting feature is that it doesn't have the modules stuck up in the front where the original 16-module Model S/X stuck the extra two modules that didn't fit in the main under-floor area. Instead, that front area is used for ancillary equipment which was separate from the original pack, taken from the "penthouse" of the Model 3 pack.
 

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The electrical connections between the modules are welded together - there is not even a pretense that one of these modules will ever be replaced, because Tesla's plan is apparently that once a pack comes out of a car, it is entirely scrapped, never fixed.

If the original Model S/X modules are a bit awkward due to their proportions and the Model 3 modules are very difficult to accommodate, this is essentially one big box that effectively doesn't break down into modules. Forget salvaging this battery for anything unless it has an underfloor space the size of that in the Model S.
 

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The narrator keeps referring to "bus bars", but while the items he's pointing out are bars they're not bus connections at all: they are all point-to-point conductors. It is interesting that (presumably for packaging) they are flat bars rather than cables.
 

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Discussion Starter · #5 ·
"It is capable of sustained 2300A output at a max voltage of 462V (That's over 1 megawatt!). "

What about this current output - seems like a lot to me! but i'm not familiar with whole pack current outputs generally.

So this pack has a max power output of 1062kW! which is just over 1400HP!
 

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"It is capable of sustained 2300A output at a max voltage of 462V (That's over 1 megawatt!). "

What about this current output - seems like a lot to me! but i'm not familiar with whole pack current outputs generally.

So this pack has a max power output of 1062kW! which is just over 1400HP!
The whole-pack current is the same as the individual module current, because the modules are in series (like all production EV packs).

Two notes to put some reality to this...
462 V is the maximum voltage, not the nominal voltage of about 400 volts. The moment the car drives away from the charging station, the voltage available starts to decrease, and that calculated power is not available. This pack as it sits is at 34.3% charged, 3.595 V/cell, and so 395 V... far from 462 V, and possibly capable of 909 kW.
The ratio of momentary peak power (available for what, 3 seconds?) to pack energy capacity is not very different from other high-power batteries. A 16 kWh pack from a Chevrolet Volt hybrid is good for 120 kW in GM's rating, and far more in practice. It's the size of six Volt packs with a roughly proportional peak power ability.

But yes, it's a big battery. :)
 

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Discussion Starter · #7 ·
The whole-pack current is the same as the individual module current, because the modules are in series (like all production EV packs).

Two notes to put some reality to this...
462 V is the maximum voltage, not the nominal voltage of about 400 volts. The moment the car drives away from the charging station, the voltage available starts to decrease, and that calculated power is not available. This pack as it sits is at 34.3% charged, 3.595 V/cell, and so 395 V... far from 462 V, and possibly capable of 909 kW.
The ratio of momentary peak power (available for what, 3 seconds?) to pack energy capacity is not very different from other high-power batteries. A 16 kWh pack from a Chevrolet Volt hybrid is good for 120 kW in GM's rating, and far more in practice. It's the size of six Volt packs with a roughly proportional peak power ability.

But yes, it's a big battery. :)
Ah of course, thanks, I was just 'thinking out loud' and wondering if that would have been the same pack used in the cancelled Plaid + if it had plenty of power in reserve. Probably not then!
So at 34.3% charge and 909kW and assuming 95% efficient motor/inverter is 818kW Motor power which is 1096HP (still struggle to quantify kW!) Is that anywhere close to reality?
 

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So at 34.3% charge and 909kW and assuming 95% efficient motor/inverter is 818kW Motor power which is 1096HP (still struggle to quantify kW!) Is that anywhere close to reality?
Yes, I think so, although efficiency will not be that high a low speed. Just accelerating the 2,162 kg mass of a Model S Plaid from zero to 60 MPH takes 778 kJ, so doing it in 1.99 seconds requires an average of 391 kW (524 HP) after tire losses, plus the power to overcome drag. With power limited by traction for much of the run, it makes sense that the peak output of the three motors in total is close to 818 kW or 1100 HP.
 
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