Home Battery System GuideThe BLUETTI EP900 and EcoFlow DELTA Pro Ultra are two modular home energy storage systems built around LFP cells. This comparison lists only published figures so the numbers read directly rather than through a ranking.
How to read this comparison
Every figure below comes from a named source: BLUETTI's EnergySage listing and EcoFlow's product page. Capacity in kilowatt-hours sets runtime, and output power in kilowatts sets simultaneous load. Both systems are modular, so totals depend on how many battery packs are installed.
Because both stack, single-configuration numbers are a scale note, not a quality judgment.
No winner is declared. The right choice depends on target size, output needs, and installer or dealer support.
BLUETTI EP900, from BLUETTI's specs
EnergySage lists the BLUETTI EP900 with a maximum capacity of 19.8 kWh and 9 kW of maximum output power. It uses a Lithium Iron Phosphate battery pack with an intelligent BMS.
EnergySage lists an efficiency of 85% for the EP900 and a 10-year warranty.
EcoFlow DELTA Pro Ultra, from EcoFlow's specs
EcoFlow lists 6,144 Wh of capacity per DELTA Pro Ultra battery, and the system is modular and stacks to reach far higher totals. The unit delivers 7,200W of AC output at 120V/240V, 60Hz.
EcoFlow uses EV-grade LFP cells and backs the DELTA Pro Ultra with a 5-year full warranty.
Where they differ on paper
Per-unit capacity is stated differently. The EP900 lists a maximum of 19.8 kWh for the system, while the DELTA Pro Ultra lists 6,144 Wh per battery and stacks to higher totals.
On output power the EP900 lists 9 kW maximum, while the DELTA Pro Ultra lists 7,200W. Both use LFP chemistry, with EcoFlow specifying EV-grade cells.
Warranty differs on paper: BLUETTI lists 10 years, while EcoFlow lists 5 years. Which fits depends on target capacity, output needs, and dealer support.