Here’s a little capture of the comm between a Tesla Model S battery module and the master board. As you might imagine, Tesla did not exactly provide a handy protocol specification document for this. 
So, the only references are open source projects. Luckily, I did write one of those: https://github.com/collin80/TeslaBMS
ModelS_BMS.sal (9.7 KB)
I haven’t taken the time to built a python HLA for this yet. If I remember correctly the various commands and responses are more or less static in length so it should be possible to write some sort of state machine that interprets the data into a higher level output.
The BMS uses an extremely odd bit rate so it’s kind of interesting from that perspective. The async serial decoder seems to be working well and results fill out the table properly.