How do you calculate good charger capacity for a demand window?

Multiply output per cycle by available cycles to get gross capacity, then multiply by uptime and first-pass yield. Here 10 units/cycle over 180 cycles is 1,800 gross, derated by 88% uptime and 93% yield to 1,473 good units.

What is the difference between gross and good capacity?

Gross capacity (1,800 units) assumes the line never stops and every unit passes first time. Good capacity (1,473 units) is what you can actually ship after subtracting 216 units lost to downtime and about 111 lost to defects and retest.

Should I plan to gross or good capacity?

Always commit to good capacity. Promising the 1,800 gross figure overstates deliverable chargers by 327 units — more than a fifth of the window — and is the fastest way to miss a fleet or utility rollout date.

Which loss should I attack first, downtime or yield?

Compare the two outputs. Here downtime costs 216 units versus 111 from defects, so reliability is the bigger lever this window — but if a small yield gain is cheaper than chasing uptime, weigh effort against units recovered.

What counts as a production cycle?

Whatever repeatable unit your line plans by — a shift, a takt block, or a day — as long as output per cycle and available cycles use the same definition. With 180 cycles and 10 units each, gross is 1,800.

What is a good first-pass yield for EV charger assembly?

High-mix power electronics often run first-pass yield in the high 80s to mid 90s; the 93% default sits in a healthy band. Below the mid 80s, defect losses start rivaling downtime as your binding constraint.

EV Charging Infrastructure Manufacturing calculator

Demand Capacity Planner Calculator

Demand-capacity planning tells an EV charger plant how many good, shippable units it can actually deliver inside a demand window — not the theoretical line rate, but the number that survives downtime and first-pass yield. It matters because charger programs ship against utility and fleet rollout dates, and a gross-capacity promise that ignores 88% uptime and 93% yield will miss commitments. Production planners and supply chain managers use it to commit delivery dates, decide whether to add shifts, and stress-test a build plan before signing a PO. The split between capacity lost to downtime and capacity lost to defects also tells you which lever — reliability or quality — actually unlocks more shippable chargers.

What this calculator does

Estimate good charger production capacity available to cover site, fleet, or customer demand.
a planner needs to know whether charger production capacity covers customer or site demand
It computes the good, shippable charger capacity available to a demand window by derating gross capacity (output per cycle times available cycles) for expected uptime and first-pass yield.

Formula used

Gross demand-window capacity = chargers or ports per cycle × available production cycles
Good capacity available to demand = gross capacity × expected uptime × expected first-pass yield

Inputs explained

Chargers or ports produced per cycle:
Available production cycles for demand window:
Expected production uptime:
Expected first-pass production yield:

How to use the result

Use it when committing delivery dates for a charger program, deciding whether existing cycles cover demand, or sizing the gap before adding capacity.
It uses single average uptime and yield figures; a line with high variability or a ramp curve will see real output swing around this point estimate, so treat it as a planning midpoint, not a guarantee.

Current U.S. benchmarks

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.

Common questions

How do you calculate good charger capacity for a demand window? Multiply output per cycle by available cycles to get gross capacity, then multiply by uptime and first-pass yield. Here 10 units/cycle over 180 cycles is 1,800 gross, derated by 88% uptime and 93% yield to 1,473 good units.
What is the difference between gross and good capacity? Gross capacity (1,800 units) assumes the line never stops and every unit passes first time. Good capacity (1,473 units) is what you can actually ship after subtracting 216 units lost to downtime and about 111 lost to defects and retest.
Should I plan to gross or good capacity? Always commit to good capacity. Promising the 1,800 gross figure overstates deliverable chargers by 327 units — more than a fifth of the window — and is the fastest way to miss a fleet or utility rollout date.
Which loss should I attack first, downtime or yield? Compare the two outputs. Here downtime costs 216 units versus 111 from defects, so reliability is the bigger lever this window — but if a small yield gain is cheaper than chasing uptime, weigh effort against units recovered.
What counts as a production cycle? Whatever repeatable unit your line plans by — a shift, a takt block, or a day — as long as output per cycle and available cycles use the same definition. With 180 cycles and 10 units each, gross is 1,800.

Last reviewed 2026-05-12.