Trying to understand cell no 38

[vh2q]

Replaced 5 cells about a year ago incl no 38 to rectify sag. Took care to match voltages. Now cell 38 starts out level but then drops off faster than the rest hitting the 3v threshold at about 35 miles, when the gauge shows half tank. Upon charging it get up to 4.1v withe the rest. Conversely, three of the new cells seem to have more endurance than the rest.

Is this just a cell capacity problem?

Hobdrive says 34Ah capacity after charging, 75%.

Is this driven by no 38?

 

[kiev]

Yes the weakest cell determines the effective capacity of the pack.

That cell is weak or of lower capacity than the rest, which is why it falls faster yet charges back up quickly