Wow, those are indeed low cost. Unfortunately I am dumb if it's not Arduino.
What I had figured out is multiplexed cell warning signals with multiple Arduino boards, but not actual voltage reading of each cell. Example, you could get a warning that cell #1 is low voltage (a PWM signal from that cell's board to the main board) but not actually know what the specific voltage was.
I am going to play with the I2C communication side tonight to see if I can make it do the latter.
Yes, TurnNBurn, you will need to solder. I picked up a 35W soldering gun at Princess Auto yesterday for $15. It even came with solder. Start practicing and do some YouTube tutorials. It's really not hard.