PCB
@Machaca
Thank you for the picture of #158. It shows bypass connections which could be used to divert small part of the charging current across individual cells. Bypass can be used to fully charge all cells and also lower voltage of individual cells. This contributes to explaining why there is lots of stuff on the PCB's.
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.