So did a quick Google search of Cyber Rodeo 4680. This article popped up. Lots of great analysis and I’m sure we dissected it above.
Tesla has made design changes to the structural pack since we analyzed the Giga Berlin cutaway. We’ve discovered new details based on the Cyber Rodeo cutaway.
insideevs.com
Quick takeaways. 828 is what was shown at Cyber Rodeo. 74.1kwh is what this pack has and that is 5x 2170 so Tesla has delivered upon their claims.
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There appears to be extra space for more cells but it would mess up the 4x3 arrangement. To keep design consistent they’d need to be 5x3 which would be 1035 cells and 92.6kwh. Current 2170 pack is 54” wide and the 4x3 arrangement is approx 44. To add the 5th module gets you to 55” with no extra space for electronics or cooling.
I am guessing maybe they need these module arrangements of 3 sets of 69 cells for the voltage they require so they can only add in 207 cell increments. Based on the collector plates. Maybe there is room and design flexibility to add more of these 69 cell groupings. Adding 1 gets you to 80.2kwh, 2 gets 86.4kwh. But it doesn’t work on the electrical side. That is why there is the MY AWD. Trying to get more cells doesn’t work unless you change pack voltage and everything associated with it? Or also structural related?
Still curious on the pack we saw with 2 missing modules, 690 cells, that we assumed was the MY AWD pack. 17% smaller with resulting 16% less range. Those numbers all made sense. It is this 828 cell full pack only giving 279 miles range that throws all those assumptions off. Also note the 5x capacity at 74.1 is just a guess. We think we know 69kwh usable so that would reserve 5kwh for pack health. A lot more than the 3kwh of the 82kwh LR pack.
Another thing to consider, the 5x numbers were based on the 2170 pack at that time, the then LR M3 78kwh total pack. 75kwh usable. Using those numbers, 0.0170 is the per cell density, not 0.0179. Multiplying by 5 and 828 gets you to 70.3kwh which is much closer to the 69kwh we think is usable on the current pack. That is much closer to the 5x prediction. About 98% of expected gain. 0.083 per cell vs 0.085. 4.88x. And even those are guesses since that is using usable kWh instead of total. Lots of flexibility in calculating these things.
We all may be guilty of using battery day numbers from then and applying to current equipment that has seen advances since then.
Just some thoughts to ponder as we learn more about the current 4680 pack.