Top balance cells?

[OTRwSolar]

Can anyone explain this?
I ran a few minor charge and discharge cycles and if I set the overvoltage at 3.4-3.45v then the cells charge balance correctly.
However if above that from 3.5-3.6v then the cells will not balance.
I have one cell that is always lagging. Cells 1-3 are close but set at 3.5-3.6v, Cell 4 is always low.

I ordered an active balancer but I am curious about the above. Is Cell 4 a bad cell?

The delta typically remains very low when charging up to approx. 3.4v---even if the cells are somewhat unbalanced. Above 3.4v is typically when the delta rises quickly if you have unbalanced cells. Bottom line, normal behavior (when cells are unbalanced).

Need to top-balance before you can make any conclusions about bad/weak cells.

 

[tammons]

If you top balance all the cells, what will be the indicator that one cell is weak?