Most of this site is about portable boxes. The Delta Pro 3 is not portable in any meaningful sense — at 114 lb measured it is a wheeled appliance you position once. What it is, is the most efficient unit anybody has put on a load bank, and the only one here that can actually run a 240 V appliance.
What the measurement says
OutdoorGearLab measured 3,790 watt-hours delivered from a rated 4,096 Wh — 93%.[1]
That is the highest measured efficiency of any unit on this site, against a category norm of 84–87% and a worst case of 75%.[2]
Some of that is physics rather than engineering: an inverter's fixed overhead is a much smaller share of a 4 kWh pack than of a 288 Wh one. But 93% is exceptional even among large units — EcoFlow's own previous-generation Delta Pro managed 82% from a 3,600 Wh rating in the same laboratory.[2]
What 3,790 watt-hours runs
Calculated from measured capacity — assumptions here.
| Load | Draw | Calculated runtime |
|---|---|---|
| Full-size household fridge | 150 W at 35% duty | 72 h 11 |
| 12 V camp fridge | 45 W average | 84 h 13 |
| CPAP, humidifier off | 35 W | 108 h 17 |
| Fridge, lights, router, phones | 250 W | 15 h 10 |
| Window air conditioner | 900 W | 4 h 12 |
| Well pump, running | 1,500 W | 2 h 32 |
Three days of refrigeration from one charge is the headline. In practice a house draws more than a fridge, and the fourth row is closer to a real outage: about fifteen hours of keeping the essentials alive.
The 240 V question
This is the Delta Pro 3's real differentiator and the reason it appears in a home-backup context at all.
It provides native 120 V and 240 V split-phase output, through NEMA 14-30 and 6-20 outlets among others.[3] Everything else measured on this site is 120 V only.
That matters for a specific and short list of appliances: a well pump, an electric dryer, most central air handlers, an electric range. Everything on a normal household circuit is 120 V and does not care.
Recharge
Measured at 3 hours 12 minutes to full, averaging 1,293 Wh per hour.[1] For 4 kWh that is fast in absolute terms, though it is the slowest figure on this site in elapsed hours simply because there is so much to fill.
One gap worth recording: OutdoorGearLab measured a peak charge rate of about 1,600 W against an advertised 1,800 W.[1] Not egregious, but it is a claim that measurement did not fully support.
Solar is the standout: 2,600 W across two MPPT ports — a high-voltage port up to 1,600 W and a low-voltage port up to 1,000 W.[3] That is more than double any other unit here and enough to refill the pack in a single good day from a real array.
Build, expansion and durability
LiFePO4 rated for 4,000 cycles to 80%, five-year warranty.[3] EcoFlow puts that at roughly eleven years of daily cycling.
4,000 W continuous, 8,000 W surge, and X-Boost to 6,000 W.[3] Expansion runs to 12 kWh on a single unit with two extra batteries, and up to 48 kWh as a paired system with 12 kW of output.[3] UPS switchover is specified at 10 ms.
Measured weight 114.1 lb against a specified 113.5.[1][3] It has wheels and a handle. It is not a two-person lift so much as a one-person drag.
Where it falls short
- 114 lb. Plan where it lives before you buy it.
- Peak charge rate measured below spec — about 1,600 W against 1,800 W advertised.[1]
- The most expensive unit on this site at $3,699 list, and about $0.98 per usable watt-hour — worse value per watt-hour than several units a tenth of the price.[3]
- Noise is a manufacturer claim. EcoFlow specifies around 30 dB in its X-Quiet mode; no independent laboratory has measured it under load.
- Whole-home use is not a purchase, it is a project. Transfer switch, electrician, permit.
How it scores
How this score is built →
Against the Anker SOLIX F3800 Plus
The obvious rival is the Anker SOLIX F3800 Plus, which on paper beats it: 6,000 W continuous against 4,000 W, 9,000 W surge against 8,000 W, and a lower price.[4]
We still recommend the Delta Pro 3, for one reason: nobody independent has measured the Anker. No published usable-capacity figure exists for it, and the one substantial hands-on review states that it is not a controlled test.[5] Anker's own product page also gives two different weights and two different solar-input figures.[4]
That is a specification against a measurement, and on this site a measurement wins. The full comparison is here.
FAQ
How long will the EcoFlow Delta Pro 3 run a house?
Not a whole house. It will run selected circuits: about 72 hours for a fridge alone, or roughly 15 hours for a realistic outage load of fridge, lights, router and phones at 250 W. Calculated from the measured 3,790 Wh usable capacity.
Does the Delta Pro 3 really output 240 V?
Yes — native 120 V and 240 V split-phase from a single unit, including NEMA 14-30 and 6-20 outlets.[3] It is the only independently measured unit on this site that does.
Is 93% usable capacity unusually good?
Yes. The category norm is 84–87% and the worst measured unit here returned 75%. Larger packs are inherently more efficient, but EcoFlow's own previous-generation Delta Pro managed only 82% in the same laboratory.[2]
Can I connect it to my home's wiring myself?
In most US jurisdictions, no — that is licensed electrical work requiring a transfer switch and usually an inspection. Doing it wrong can energise the utility line and kill someone working on it. Consult a licensed electrician.
How much solar does it take?
2,600 W across two MPPT ports, more than double anything else here.[3] That is enough to refill the pack from a real array in one good day.
The one to buy if it is not moving
The Delta Pro 3 is the best-measured unit on this site and the only tested one with real 240 V output. If you want a battery that keeps a fridge, a freezer and the lights going for two or three days, and can start a well pump, this is the evidence-backed answer.
The reservations are all practical rather than technical. It costs the most and it is not good value per watt-hour. It weighs 114 pounds. And using it as home backup properly means a transfer switch and an electrician, which is a project rather than a purchase.
The Anker SOLIX F3800 Plus looks better on paper and costs less. Until somebody measures it, that is all it does.
Sources
- OutdoorGearLab. EcoFlow Delta Pro 3 Review. Independent lab test · accessed 5 September 2026
- OutdoorGearLab. The Best Power Stations of 2026 — Lab Tested & Ranked. Independent lab test · accessed 5 September 2026
- EcoFlow. DELTA Pro 3 Portable Power Station — specifications. Manufacturer spec · accessed 5 September 2026
- Anker SOLIX. SOLIX F3800 Plus — specifications. Manufacturer spec · accessed 5 September 2026
- AppleInsider. Anker SOLIX F3800 Plus review — a practical assessment, not a controlled lab test. Hands-on review, not a lab test · accessed 5 September 2026