This study dwells upon two key aspects of cell sorting including what descriptors should be concerned and how stringent the limits of these descriptors should be. Evaluation is made on a parallel multi-cell block using an electric circuit modelling (ECM) approach, which features a model validation based on separate current tracking of each cell in the parallel cell block via Hall sensors, and a detailed comparison of methods to determine model parameters. We find that: (1) the ECM can accurately capture the current balancing behavior in the parallel block; (2) the current interrupt method with a rest duration of 120s is recommended for the determination of cell resistance; (3) the current distribution in the parallel block is insensitive to the hysteresis in open circuit voltage (OCV); (4) cell-to-cell variations decrease the capacity of the block (5) a descriptor accounting for aging variations among cells is suggested to be included in the cell sorting process and the OCV drop rate can be a potential candidate.