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Delta Electronics E4

9.8 kWh · 3.65–4 kW · Lithium Ion · direct PV input · 2 configurations

UL 9540CEC listed · May 3, 2021
  • Nameplate energy9.8 kWh
  • Continuous power3.65–4 kW
  • ChemistryLithium Ion

Overview

CEC Energy Storage System List

E4: 9.8 kWh nameplate energy; 3.65–4 kW continuous; lithium ion; accepts solar panels directly (DC-coupled).

Models & configurations

CEC Energy Storage System List · 2 listings
ModelEnergyPowerGrid voltageRound tripCEC listed
E4 {208V}9.8 kWh3.33 kW208 V—May 3, 2021
E4 {240V}9.8 kWh3.84 kW240 V—May 3, 2021

Capacity & power

CEC Energy Storage System List

Charging from solar in Southern California

NLR PVWatts v8 · Cali-Graf calculation · CEC Energy Storage System List
CityDecemberJune
Los Angeles3.1 kW1.8 kW
Palmdale2.8 kW1.6 kW
Chula Vista2.6 kW1.9 kW
Huntington Beach2.9 kW2 kW
Riverside2.9 kW1.7 kW
Santa Clarita2.9 kW1.7 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 Energy Storage System List
UL 9540 certifies the whole storage system; UL 9540A is the fire-propagation test that fire codes ask for indoors and near walls.

California grid & code compliance

CEC Energy Storage System List

Compare with similar batteries

CEC Energy Storage System List
BatteryEnergyContinuous powerChemistryWarrantySoCal permits
Enphase Energy ENCHARGE-1010.1 kWh3.84 kWLithium Iron Phosphate10 years197
Enphase Energy IQ Battery 10C10 kWh7.08 kWLithium Iron Phosphate—118
Enphase Energy ENCHARGE-10T10.1 kWh3.84 kWLithium Iron Phosphate15 years105
Enphase Energy Q Battery 10C10 kWh7.08 kWLithium Iron Phosphate——
Villara Energy Systems VillaGrid5.8–11.5 kWh8 kWLithium Titanate Oxide20 years—
SolarEdge Home Battery9.7 kWh5 kWLithium Ion10 years677
Same segment, similar capacity; each row from the same sources.

Questions & answers

How much energy does the Delta Electronics E4 store?

9.8 kWh nameplate, per the California Energy Commission list.

Is the E4 UL 9540 certified?

Yes — the CEC list shows UL 9540 certification (certified by csa group).

Sources

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