Whole-circuit class
EcoFlow DELTA Pro 3 Portable Power Station
A 4 kWh, 4,000 W, 120/240 V unit that connects to a transfer switch and backs up circuits, not just devices — a fuel-free alternative to a standby generator once an electrician installs the transfer switch.
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Best for
Backing up real circuits — furnace, well pump, kitchen — without fuel
Specifications
| Capacity | 4,096 Wh LFP (expandable to 12 kWh/unit, 48 kWh system) |
|---|---|
| Cycle life | 4,000 cycles to 80% |
| AC output | 4,000 W at 120/240 V / 8,000 W surge |
| Outlets | 7 AC incl. 30 A RV + L14-30 split-phase |
| Solar input | 2,600 W max |
| Recharge (AC) | 0-80% in 50 min (multi-input to 7,000 W) |
| UPS switchover | 10 ms |
| Certification | UL 9540 |
| Weight | 113.5 lb (wheeled) |
| Warranty | 5 years |
Specifications as published by EcoFlow. Confirm against the current spec sheet before buying — manufacturers revise models without renaming them.
What's good
- Split-phase 240 V and an L14-30 outlet — it can feed a transfer switch like a generator, silently and indoors
- Expandable to 12 kWh per unit; EcoFlow's Smart Home Panel integrates it as automatic whole-home backup
- 2,600 W of solar input can genuinely recharge it in a day
What's not
- 113 lb — wheeled, but this is an appliance, not a camping item
- Feeding circuits still takes a transfer switch or EcoFlow's Smart Home Panel, installed by an electrician and usually under a permit
- Standby-generator price territory — compare it against that install honestly
Our verdict
This is the machine that changed the standby-generator conversation: transfer-switch-ready 240 V backup with no gas line, no fuel and no noise, plus solar recharge mid-outage. The transfer switch is still an electrician's job. If your outage plan involves circuits rather than extension cords, start here and size the expansion batteries from your load calculation.
Compare with the alternatives
- Jackery Explorer 1000 v2 — first power station — fridge, phones, lights and cpap through an outage
- Bluetti Elite 200 V2 — most capacity and battery longevity per dollar in the 2 kwh class
- Jackery HomePower 2000 Plus v2 — starting at 2 kwh with a real expansion path
- Jackery Explorer 2000 v2 — 2 kwh of backup you'll move around, not install
- Anker SOLIX C1000 Gen 2 — the 1 kwh class's strongest inverter and fastest recharge
- Bluetti AC180 — the budget route to a serious 1 kwh station
- Goal Zero Yeti 1000 (LiFePO4) — solar-first recharging and goal zero's transfer-switch ecosystem
- EcoFlow RIVER 3 Plus — desk ups duty, camping, and finding out what you actually need