@jwildeboer I've been looking at getting a replacement battery for my late-Gen Classic. Consensus seems to be that it's a crapshoot. They're all new old stock at this point, it's rare that the recognizable online parts stores catering to the scene sell batteries themselves, and the sellers on places like AliExpress are constantly changing, so you just need to take your chances with one.
Also, FWIW, I've bought laptop batteries on iFixit (EU) in the past, paying a premium for what I expected to be good quality, and the battery I got was already quite degraded. I complained and got another one, in basically the same state. Sure, that's great customer service, but I don't feel like the outcome was substantially different vs just ordering from a cheaper place?

