How long can the EcoFlow DELTA Pro 3 run a Space heater?

4.6 hours

Formula: (4.1kWh × 0.85 inverter efficiency) ÷ 18 kWh/day = 4.6 hours. At continuous 1500 W draw (no duty cycle), about 2.3 hours.

What if you add a battery? The + Extra Battery config jumps to 8.2kWh — roughly 9.3 hours on a Space heater.

Appliance

Space heater · 1500 W / 1500 W surge

Battery (base)

4.1kWh · 4kW / 8kW surge

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Runtime Quick-Check

Pick a battery and an appliance — see days of runtime after the 0.85 inverter derate.

BatteryApplianceQuantity

4.6 hours

Formula: (4096 Wh × 0.85) ÷ 18 kWh/day = 4.6 hours. Continuous draw ≈ 2.3 hours at full load.

Running more than one device?