saptzae
This contributes to explaining why there is lots of stuff on the PCB's.
Did you see this approach used before? How many amps to be shunted? Voltage control loading a charging (or charged cell) through by pass?
With these thin wires seems just impossible to control cell voltages during the charging. A likely scenario (during charging) JAL BOS fire.
Again, parallel charging is the only way i can imagine to adequately manage cell voltages during charging.
In the lower right, at the bus bar, there seems to be a breaker used to disconnect the battery from the bus. If so, I wonder whether it was opened and remained open after the initial failure.
After loosing control of a given cell voltage, thermal effects will kick in (may be impossible to revert the runaway) and the opening of the main battery connection to the bus may not help at all. I heard on the use of a diode in the main battery circuitry. Anyway means of disconnection of the battery to the bus seems mandatory with Li Ion.