Originally Posted by saptzae
I suspect that NTSB schematic is simplified. It appears that there is no cell balancing. This would be ridiculous because it would lead to Primary failure.
I agree that the schematic obviously does not show all connections or components. Regarding balancing, there is a small explicit reference in the Materials Laboratory Factual Report released on March 7.
Page 4 of the lab report includes the text "The BMU performs cell balancing on cells over 4.00 V and monitors overall battery voltage for under-voltage conditions."