EV & Battery Manufacturing worked example

Cell Aging Inventory Days with released aged-cell inventory on hand of 72,000 cells: a worked example

This worked example runs the cell aging inventory days numbers for a tougher week than the baseline: released aged-cell inventory on hand of 72,000 cells instead of the typical 144,000 cells. Estimate protected days of released aged-cell supply from cell inventory, downstream demand, and safety factor.

The inputs for this scenario

  • Released aged-cell inventory on hand: 72,000 cells (the input this scenario stresses; the baseline uses 144,000)
  • Daily downstream cell draw: 24,000 cells / day (held at the documented default)
  • Aging buffer safety factor: 1.2 x (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Unprotected aged-cell days = released aged-cell inventory รท daily downstream demand.
  • Protected aging inventory days works out to 2.5 days at these inputs, and this is the headline figure for the scenario.
  • Unprotected aged-cell days works out to 3 days at these inputs.
  • Released aged-cell inventory works out to 72,000 cells at these inputs.
  • Daily cell demand works out to 24,000 cells / day at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where released aged-cell inventory on hand sits at 144,000 cells and the headline result is 5 days, this scenario comes in 50% below the baseline at 2.5 days.
  • Use it for daily aging-room replenishment decisions and to check whether released stock can survive an aging-line stoppage. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Protected aging inventory days: 2.5 days (headline result)
  • Unprotected aged-cell days: 3 days
  • Released aged-cell inventory: 72,000 cells
  • Daily cell demand: 24,000 cells / day

Run it with your numbers

  • To rerun this with your own numbers, open the live Cell Aging Inventory Days calculator, set released aged-cell inventory on hand to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.