This is a little bit of an over-simplification. These particular 21700 and 4680 Panasonic cells are not off-the-shelf or catalog. As far as I know, they were de

This is a little bit of an over-simplification. These particular 21700 and 4680 Panasonic cells are not off-the-shelf or catalog. As far as I know, they were designed specifically with the EV application and Tesla pack in mind. And to my knowledge, the Tesla Panasonic cell variants only exist in Teslas. We could not take some other 21700s and make a roughly equivalent pack without a good deal of effort. The thermal characteristics, impedance, length, width, diameter, would be different. There may not even be any cells available with equivalent form factor and performance characteristics. We haven't seen Tesla or anyone else taking "commodity" 21700 cells and mixing and matching them and throwing them into a pack, it's not possible to do that. Usually, we pick one or two cell manufacturers. It's telling that even Tesla, with their massive buying power, doesn't purchase from LG, Sony or Samsung, only Panasonic in the West for NCA and CATL in China for LFP. Why exactly do we think that is? It's not quite at the level of people saying computer chips are commodities, and you can just plug your device into one interchangeably. But these cells are not easy and simple. We tend to just think something's easy because we don't have good experience with it. For lithium ion, under the hood, there's enough complexity and risk that the details become very important, very quickly.