I have a few good pouch cells left over from some failed battery banks. Contemplating making up my own super sized battery for my 11th Gen i5 FW13 mainboard (that is in a 3d printed case, not a laptop shell).
Yes, I do believe so.
Normally, laptops communicate with a Li-Ion BMS (Battery Management System) over data pins, the SMB labeled pins. This provides estimation of the charge level, tracking wear, and charge cycles. BMS’es also provided needed safety fuctions, monitoring temperature and individual cell voltage. Due to this, the mainboard will likely refuse to charge or accept power if it is unable to find and communicate with a BMS. The BMS data pin is labeled in the pinout on Framework’s github. And the mainboard EC (embedded controller) is open source, so what it needs to see from the BMS would be found there, if nowhere else.
It may be much easier to turn them into a big power-bank instead and and connect them to the framework that way.
To directly connect them you’d need to build a very specific bms and likely changes to the embedded controller to support the likely lower charge voltage of your cells.