Grid-Scale Battery Energy Storage Systems worked example

Module Yield at 99% target module yield rate: a worked example

What does the result look like when target module yield rate reaches 99%? The full calculation is worked below with real intermediate numbers. Use it when the BESS module formation and capacity test line needs a clean yield rate and gap-to-target figure for the daily tier board or for a corrective action decision on cell chemistry or formation protocol.

The inputs for this scenario

  • Battery modules passing formation and capacity test: 237 modules (unchanged)
  • Total battery modules entered into test: 250 modules (unchanged)
  • Target module yield rate: 99 % (raised for this scenario; the documented default is 95)

Working through the calculation

  • Applying the documented formula (Module first-pass yield rate = modules passing formation test / total modules entered into test x 100) to the inputs above produces each figure below.
  • At this operating point the engine returns 94.8 % for module first-pass yield rate, the number this scenario is built around.
  • At this operating point the engine returns 4.2 points for module yield gap to target.
  • At this operating point the engine returns 237 count for modules passing formation and capacity test.
  • At this operating point the engine returns 250 count for total modules entered into test.

How this compares with the baseline

  • Against the tool's baseline example, where target module yield rate sits at 95% and the headline result is 94.8 %, this scenario lands almost exactly on the baseline at 94.8 %.
  • A figure at this level is achievable when target module yield rate is genuinely sustained, not just peaked for a shift. First-pass yield treats every failure equally, so a batch of borderline-low-capacity modules and a batch of dead cells look identical here — you still need failure-mode Pareto data to act.

Results at a glance

  • Module first-pass yield rate: 94.8 % (headline result)
  • Module yield gap to target: 4.2 points
  • Modules passing formation and capacity test: 237 count
  • Total modules entered into test: 250 count

Run it with your numbers

  • Every input above is editable in the live Module Yield calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.