Minor quibble, and I don’t know for certain, but I suspect the 18650s in a battery pack are welded and not soldered.
That’s how they’re connected on most smaller devices, using a somewhat specialized pinpoint welding technique that I assume heats the metal (and the cell) a lot less than soldering would. You can buy DIY setups on ebay for small projects - I assume it’s scaled up on the EVs but uses a similar tech for similar reasons.
Of course, I could be wrong...
Here’s a low-end battery spot welder as an example.
https://www.amazon.com/Aideepen-Handheld-Adjustable-Portable-Stainless/dp/B0BZS4H6WP?th=1
I think you are right and that was a poor choice of wording - its all done by machine for the connection. My point was that there is a LOT of potential for failure among small components anywhere within the pack or even between the sheets of anode/cathode in the battery.
Like I said, it is amazing that they exist at all when you understand more about the batteries!
“Minor quibble, and I don’t know for certain, but I suspect the 18650s in a battery pack are welded and not soldered.”
Welded, per Tesla.