Industry2026-09-16
Why pack builders set a grading window before welding
Sorting cells by voltage and internal resistance is the cheapest consistency measure in a pack workshop.
Parallel groups made from mixed batches drift apart under load, and the weakest cell sets the group. A grading window applied before welding keeps the spread inside a defined range.
The window itself depends on the cell supplier's batch data and the pack's duty cycle, so it is agreed per project rather than copied from a general rule.
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