[PLUG] DIY Thinkpad BMS and battery modules

[tom]

Has anybody got any details on the specifications for the communication
between the embedded controller and the battery module for the ThinkPad
T430? Also perhaps some CAD schematics of the battery module enclosure?
I'm not worried about the cryptographic handshake to verify battery
'authenticity' as I've already replaced the proprietary BIOS with
CoreBoot which doesn't halt the CPU when an "Unauthorized" battery
module or mPCI expansion card is installed into the system.

The Lithium Ion cells Levonvo used to manufacturer their batteries have
a lot of short comings and the 'genuine' cells are starting to suffer
from age. Even if you were to get a newstock one Lenovo did not choose
the highest quality cells and instead opted for lower amp hour lower
endurance cells which do not last as long.

I already am familiar with the Lenovo BMS in the fact that they have
boobietrapped their hardware in an attempt to prevent owners from
modifying and repairing their own machines. Where you have to measure
the voltage of the existing cells and apply a similar DC voltage to the
BMS and each balance lead as dropping to 0VDC would cause the BMS to
brick itself. Compound this with the fact the module enclosure is
glued together and made with very thin shred-able plastic. While this is
doable I'm looking for a cleaner option. Perhaps a cleanroom design
from the ground up with modern cells and modern microcontrollers.

Has anybody attempted to do this before and has some work I can
continue off of?

Sort of an unrelated note but I would also be interested in motherboard
schematics that could be used to design a replacement mainboard in
the future with a modern ARM64 or RISCV (if that riscv matures) cpu
instead of the aging X86 Intel cores. If your not required to run
Microsoft Windows and have the source code to all of the programs you
rely on for productivity there's really no reason at all to use X86
chips with all the heat they produce, power they consume, and
vulnerabilities they have.

Provided you can get the power draw down you could even start
experimenting with different battery chemistries better suited for the
cycling and sustained usage of mobile computers.