How do you calculate leak-test capacity?

Multiply packs per cycle by available cycles for gross capacity, then multiply by uptime and first-pass yield. With 2 packs/cycle, 220 cycles, 90% uptime, and 97% yield, gross is 440 and good capacity is 384.12 packs.

Why is good capacity lower than gross capacity?

Downtime and failures eat into it. Here 440 gross packs lose 44 to downtime (10% uptime loss) and about 11.88 to first-pass failures, leaving 384.12 good leak-tested packs.

What is a good first-pass leak-test yield?

Mature pack lines often run 96-99% first-pass on leak test once sealing and gasket processes are stable; the 97% default sits in that band. Persistent yield below 95% points to seal-process or fixture problems.

How much does station uptime cost me?

Uptime scales capacity directly. At 90% uptime you forfeit 44 of 440 gross packs; lifting uptime to 95% would recover roughly 22 of those packs before yield is even applied.

Is leak testing my line bottleneck?

Compare good capacity to pack build rate. If assembly completes more than 384 packs in the same period, the leak-test station gates the line and needs more cycles, a faster fixture, or parallel stations.

Should I model retest in this calculator?

This is a single-pass model, so packs that fail and get reworked aren't recovered here. If retest is common, treat the 11.88 failed packs as a separate rework stream that competes for the same cycles.

EV & Battery Manufacturing calculator

Battery Pack Leak Test Capacity Calculator

Battery Pack Leak Test Capacity estimates how many sealed packs your leak-test station can actually certify as good in a given period. Leak testing - typically helium or pressure-decay - verifies the coolant and enclosure seals that keep an EV pack safe, and it is frequently the gating station before final assembly. Manufacturing and quality engineers use this to confirm test throughput keeps pace with pack build rate and to quantify how much capacity downtime and first-pass failures quietly consume. A station that looks fast on paper can fall short once uptime and yield losses are applied.

What this calculator does

Estimate usable pack leak-test capacity from packs per cycle, available cycles, test uptime, and first-pass leak yield.
a pack line needs to confirm helium, pressure-decay, or coolant-loop leak testing can keep up with assembly takt
It computes good leak-tested pack capacity as packs per cycle times available cycles, derated by station uptime and first-pass yield.

Formula used

Gross leak-test capacity = packs tested per cycle × available leak-test cycles
Good leak-tested pack capacity = gross capacity × station uptime × first-pass leak-test yield

Inputs explained

Packs tested per leak-test cycle:
Available leak-test cycles in period:
Leak-test station uptime:
First-pass leak-test yield:

How to use the result

Use it when sizing leak-test capacity against pack build rate or diagnosing whether testing is the line bottleneck.
It applies a single first-pass yield and ignores retest loops; packs that fail and are reworked then re-tested can either recover or further consume cycles, which this single-pass model does not capture.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).
U.S. light vehicles sell at a 16.9 million annual rate (BEA, Jun 2026), up 4.1% from a year earlier, the volume signal for automotive supply chains.
Global copper trades at $13,484 per tonne (IMF via FRED, May 2026), up 41.5% in a year, and U.S. industrial electricity averages 8.66 cents per kWh. Both feed electrified-hardware unit economics.
The U.S. has 11,691 transportation equipment establishments employing about 1,682,910 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate leak-test capacity? Multiply packs per cycle by available cycles for gross capacity, then multiply by uptime and first-pass yield. With 2 packs/cycle, 220 cycles, 90% uptime, and 97% yield, gross is 440 and good capacity is 384.12 packs.
Why is good capacity lower than gross capacity? Downtime and failures eat into it. Here 440 gross packs lose 44 to downtime (10% uptime loss) and about 11.88 to first-pass failures, leaving 384.12 good leak-tested packs.
What is a good first-pass leak-test yield? Mature pack lines often run 96-99% first-pass on leak test once sealing and gasket processes are stable; the 97% default sits in that band. Persistent yield below 95% points to seal-process or fixture problems.
How much does station uptime cost me? Uptime scales capacity directly. At 90% uptime you forfeit 44 of 440 gross packs; lifting uptime to 95% would recover roughly 22 of those packs before yield is even applied.
Is leak testing my line bottleneck? Compare good capacity to pack build rate. If assembly completes more than 384 packs in the same period, the leak-test station gates the line and needs more cycles, a faster fixture, or parallel stations.

Last reviewed 2026-05-12.