EV & Battery Manufacturing worked example

Battery Cell Rework Rate at 1.08% target maximum rework rate: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop target maximum rework rate to 1.08%, then walk the calculation through step by step. Calculate cell rework rate from reworked cells, total cells processed, and the target rework limit.

The inputs for this scenario

  • Cells requiring rework: 620 cells (held at the documented default)
  • Total cells processed: 48,000 cells (held at the documented default)
  • Target maximum rework rate: 1.08 % (the input this scenario stresses; the baseline uses 1.5)

Working through the calculation

  • The calculation starts from the formula this tool documents: Cell rework rate = cells requiring rework รท total cells processed.
  • Cell rework rate works out to 1.29 % rework at these inputs, and this is the headline figure for the scenario.
  • Rework rate gap to limit works out to -0.21 points at these inputs.
  • Cells requiring rework works out to 620 cells at these inputs.
  • Cells processed works out to 48,000 cells at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where target maximum rework rate sits at 1.5% and the headline result is 1.29 % rework, this scenario lands almost exactly on the baseline at 1.29 % rework.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to target maximum rework rate, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It treats all rework as equivalent; it does not weight a quick re-seal against a teardown, nor does it capture cells that fail rework and become scrap.

Results at a glance

  • Cell rework rate: 1.29 % rework (headline result)
  • Rework rate gap to limit: -0.21 points
  • Cells requiring rework: 620 cells
  • Cells processed: 48,000 cells

Run it with your numbers

  • To rerun this with your own numbers, open the live Battery Cell Rework Rate calculator, set target maximum rework rate to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.