Kowint Energy S4004-ST

Name: Kowint Energy S4004-ST
Brand: Kowint Energy

20.5 kWh · 15 kW · Lithium Iron Phosphate

UL 1973CEC listed · Oct 2, 2023

Overview

CEC Battery List

S4004-ST: 20.5 kWh nameplate energy; 15 kW continuous; lithium iron phosphate.

CEC Battery List

NLR PVWatts v8 · Cali-Graf calculation

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).

CEC Battery List

CEC Energy Storage System List

Battery	Energy	Continuous power	Chemistry	Warranty	SoCal permits
LG Energy Solution RESU 10H Prime	9.6–16 kWh	5 kW	Lithium Ion	—	127
Qcells Q.SAVE	9–18 kWh	5.5–11.1 kW	Lithium Iron	10 years	30
Tigo Energy TSB	9 kWh	3.5–5.2 kW	Lithium Iron Phosphate	11 years	2
FOXESS ECS4000-H5	25 kWh	14.4 kW	Lithium Iron Phosphate	—	1
RNG International Renogy X	20 kWh	10 kW	Lithium Iron Phosphate	10 years	1
GoodWe SECU-S Series	11.5–18.4 kWh	2.9–23 kW	Lithium Iron Phosphate	—	—

Same segment, similar capacity; each row from the same sources.

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