They put the old (55WH vs the newer 61WH) battery in the shell -- Framework you cheapos! I guess they are trying to get rid of the old, smaller batteries.
Also, word of warning just don't apply the 3.08 bios update if you have a 12th gen. I've had nothing but problems with the 3.08 bios update without real remediation from framework. Really, don't perform this upgrade without doing a thorough review of the support forums regarding the issues people are having.
There was a blog post about the BIOS update that i found here on this site, but i'm having trouble finding it for reference now. Someone had the same issue as i have where sometimes my system just won't boot (no video and error sequence) unless i remove or re-add a memory module. Not that fun.