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Battery energy = daily load kWh x autonomy days / depth of discharge / round-trip efficiency. For 20 kWh/day load, 1 day autonomy, 80% DoD and 90% efficiency: 20 / 0.8 / 0.9 = 27.8 kWh, so select a 30 kWh bank. The calculator computes capacity and matches standard rack/cabinet sizes.

Depth of discharge is the fraction of capacity used per cycle. LFP batteries tolerate 80-90% DoD for 6,000+ cycles; lead-acid lasts longest at 50% DoD. Deeper discharge shortens cycle life, so the battery is oversized to respect the DoD limit. The calculator applies DoD to the usable-capacity calculation.

LFP cells deliver 6,000-8,000 cycles at 80% DoD (roughly 15-20 years at one cycle/day), while NMC gives 3,000-5,000 and lead-acid 500-1,200. Calendar life and temperature also matter — operating above 35 deg C accelerates degradation. The calculator reports cycle-life implications for the sized bank.

The PCS power rating must cover the peak load and charge rate, and its DC voltage range must match the battery string. For a 30 kWh bank serving a 10 kW peak load, select a 10-15 kW PCS. The calculator matches PCS power and battery DC voltage to the sized bank.

For peak-shaving, the battery must cover the peak demand above the target for the duration of the peak window, usually 2-4 hours. Shaving 100 kW for 3 hours needs 300 kWh usable, or ~375 kWh at 80% DoD. The calculator sizes the bank for the shaving window and quantifies demand-charge savings.