Whole-circuit class
EcoFlow DELTA Pro 3
A 4 kWh, 4,000 W, 120/240 V unit that connects to a transfer switch and backs up circuits, not just devices — the no-installation alternative to a standby generator.
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Best for
Backing up real circuits — furnace, well pump, kitchen — without fuel or permits
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
- EcoFlow's affiliate cookie and stock cycles aside: the price class is standby-generator territory, so compare 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 permit, no noise, plus solar recharge mid-outage. 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 Explorer 2000 Plus — starting at 2 kwh with a real expansion path
- 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