How hi-tech is this charger? Apple computers for many years know when the battery was made, and count charge and recharge cycles and depth of discharge. Those numbers are used to estimate how much capacity the cell/pack has left. Tesla cars do this also. Apple also avoids 100% charging and floats around the 95% level to avoid the internal damage going over 4.16v/cell.
An aging lithium cell will show changes to internal resistance and how long the passivation layer takes to clear when charging or discharging is started. That could mean a different charge routine for cell detected as past their prime.