Equivalent full cycles (EFC)
A single number that normalises messy partial cycling into full-cycle equivalents.
Equivalent full cycles (EFC) express total energy throughput as the number of complete 0–100% cycles it represents, so that many partial cycles are counted fairly. EFC is the unit warranties use for the energy-throughput limit, making it the key cycle-budget metric for any BESS.
Definition
Real dispatch is a mix of partial charges and discharges, not clean full cycles. EFC sums the energy throughput and divides by the rated capacity, converting irregular operation into an equivalent count of full cycles. Partial cycles are weighted by their depth.
Formula
EFC = cumulative energy throughput ÷ rated capacity
Typical range
Warranty energy-throughput limits are stated in MWh or in EFC. LFP supports ~4,000–6,000 EFC to 80% SoH; NMC ~2,000–3,500. Storage assets typically accrue ~1.5–2 EFC/day.
Why it matters
EFC is one of the two warranty limits (alongside capacity retention) — OEMs honour whichever is reached first. Tracking EFC against the contracted budget tells you whether you’ll hit the throughput cap before the calendar limit, which changes how you should dispatch.
How NuraVolt tracks it
NuraVolt counts EFC continuously from metered throughput, projects the date the contracted EFC budget is exhausted at the current dispatch rate, and flags when cycling intensity puts the throughput limit ahead of the calendar limit.
Frequently asked questions
See also
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