[deckar01]

The Two Bit Da Vinci YouTube channel has a good video on solid state battery fundamentals and a deep dive into a battery company (ProLogium) that has demonstrated manufacturing at scale.

https://youtu.be/xQFVIs4leig?si=iOOt5gg_2MJAIoFR

[thelastgallon]

BYDs battery stress testing: https://www.youtube.com/watch?v=WPTgg3joL5E

[deckar01]

Those use liquid electrolyte cells and the video is more promo than rigorous testing.