voltage divider is not a good solution for me,
I know that is why I said it has been an epic thread in the past. You need to measure the voltage of a cell that has a DC offset of 50V.
This is not a trivial thing to do.
One 'solution' had an isolated arduino across each cell, others did it with a small 8 pin processor on each cell. My preferred solution was to have a voltage controlled oscillator on each cell and capacitavly couple the signals into an arduino where it measured the frequency.