Increasing the number of cell grading bins reduces within-module capacity spread in proportion to bin width, but grade-specific waiting WIP rises in proportion to bin count, and the time for the rarest tail bin to fill one module's worth of cells rises faster still. On an assumed line of about 4.46 million cells per year with 16-cell modules, going from 6 bins to 18 bins (6 capacity × 3 internal resistance) leaves the 0.6 Ah capacity bin width unchanged while raising average partial-fill WIP from 45 to 135 cells and tail-bin fill time from about 4,492 s to about 28,311 s. During ramp-up (operating at 30% of rated rate) this…