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46.1 kWh
Battery moduleFortress Power

Fortress Power FP-Nano-S9-I

46.1 kWh · 46.1 kW · Lithium Iron Phosphate

UL 1973CEC listed · May 21, 2026
  • Nameplate energy46.1 kWh
  • Continuous power46.1 kW
  • ChemistryLithium Iron Phosphate

Overview

CEC Battery List

FP-Nano-S9-I: 46.1 kWh nameplate energy; 46.1 kW continuous; lithium iron phosphate.

Capacity & power

CEC Battery List

Charging from solar in Southern California

NLR PVWatts v8 · Cali-Graf calculation
CityDecemberJune
Los Angeles14.3 kW8.5 kW
Palmdale13.2 kW7.7 kW
Chula Vista12.3 kW8.8 kW
Huntington Beach13.5 kW9.4 kW
Riverside13.7 kW8.2 kW
Santa Clarita13.6 kW8 kW
Solar array size that refills the battery from empty in one average day, before the home uses any of it (NLR PVWatts v8, 20° south roof).

Safety listings

CEC Battery List

Compare with similar batteries

CEC Energy Storage System List
BatteryEnergyContinuous powerChemistryWarrantySoCal permits
EG4 Electronics PP-16/280A3-18K1-AWLL43 kWh10.4–12 kWLithium Iron Phosphate10 years—
EG4 Electronics PP-16/280A3-18K2-AWLL43 kWh20.8–24 kWLithium Iron Phosphate10 years—
Power Center Duracell14–42 kWh5 kWLithium Iron Phosphate——
Same segment, similar capacity; each row from the same sources.

Sources

  1. California Energy Commission — Energy Storage System List, data as of Oct 7, 2026. Manufacturer-reported values confirmed by CEC against certificates.
  2. California Energy Commission — Battery List, data as of Oct 7, 2026.
  3. NLR (formerly NREL) — PVWatts v8, NSRDB PSM v3 typical-year weather for Los Angeles, Palmdale, Riverside, Santa Clarita, Chula Vista, Huntington Beach.
  4. Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).