Research-based review · Solar panels and kits
EcoFlow DELTA Pro 3 + 400W panel review: a 4 kWh home battery with a first solar panel for long outages
The DELTA Pro 3 bundled with one 400 W folding panel. The panel keeps the fridge side of the house going on a clear day; the station can take more than six times that much solar.
By PowerLockdown EditorialUpdated November 1, 20266 min readBased on manufacturer specs and published dataHow we research
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At a glance · EcoFlow DELTA Pro 3 + 400W panel
Best for: Buyers getting a 240 V-capable home battery who want enough solar from day one to cover a refrigerator and small loads through a multi-day outage
- Battery
- DELTA Pro 3: 4,096 Wh LiFePO4; 12 kWh with two extra batteries
- AC output
- 4,000 W at 120/240 V; 4 × NEMA 5-20R, TT-30R, 6-20R (240 V), L14-30R
- Panel
- 1 × EcoFlow 400W portable panel, monocrystalline cells under ETFE film
- Panel efficiency
- 23% on EcoFlow's bundle page (22.6% on the panel's own page)
- Panel weight and rating
- 35.3 lb; IP68; kickstand case adjusts 40 to 80°
- Station solar ceiling
- 2,600 W: High-PV 30 to 150 V (1,600 W) + Low-PV 11 to 60 V (1,000 W)
- UPS switchover
- 10 ms
- Warranty
- 5 years: 3 standard plus 2 extended on app registration (EcoFlow)
Verdict: A sensible starter pairing. One 400 W panel covers about a fridge's daily use in good sun; plan to add panels if you want the battery itself refilled by day.
In this review
This is a research-based review, based on manufacturer specs and published data. We do not test products. Figures come from EcoFlow's DELTA Pro 3 Solar Generator page and its 400W Portable Solar Panel page, checked November 1, 2026, and from the federal sources cited below.
EcoFlow sells the DELTA Pro 3 on its own (see our EcoFlow DELTA Pro 3 review) and as a solar generator with one or two 400 W folding panels. This review covers the one-panel kit and what the panel adds in an outage. The station is a 4,096 Wh, 120/240 V battery on wheels that EcoFlow says can run loads up to a 3-ton central AC or a 1 HP water pump. The panel is the part that keeps it useful once the grid has been down for more than a couple of days.
The central question is the ratio. The station accepts up to 2,600 W of solar. One 400 W panel supplies about 15% of that, so the kit is a starting point that you can grow, not a full solar system.
Who should buy it
- Households buying a DELTA Pro 3 for 240 V backup that want a matched first panel and cable in the same order.
- Homes in hurricane or wildfire shutoff areas, where outages can run several days and fuel can be hard to find.
- Buyers who want a portable panel they can fold away rather than a roof installation.
Who should skip it
- Anyone expecting one panel to refill 4 kWh in a day. On our planning math, it puts back about 1,200 Wh on a clear day.
- Households that only need a fridge and electronics covered. The Jackery Solar Generator 2000 v2 pairs a 2 kWh battery with 400 W of panels at about a third of the station weight.
- People who need to carry the panel far. At 35.3 lb it is heavier than two 200 W folding panels.
Strengths
- Large panel in one piece. 400 W from a single fold-out panel means one cable run and one thing to aim.
- Built-in stand. EcoFlow says the protective case folds into a stand that adjusts from 40 to 80 degrees.
- IP68 panel. EcoFlow lists ETFE film over monocrystalline cells and an IP68 rating.
- Room to grow. The station's 2,600 W solar input leaves plenty of headroom; EcoFlow also sells a two-panel version of the kit.
- 10 ms UPS on the station. EcoFlow lists a 10 ms switchover, so the battery can sit between the wall and your essentials full time.
- 5-year warranty when registered in the EcoFlow app.
Drawbacks
- One panel is a small share of the input. 400 W against a 2,600 W ceiling.
- Heavy panel. 35.3 lb, and the station weighs 113.54 lb.
- Efficiency figure differs by page. EcoFlow's bundle page says 23% and the panel page says 22.6%; neither changes the 400 W rating.
- Home circuits need an electrician. The station's 240 V value depends on a transfer switch or EcoFlow's Smart Home Panel 2, which EcoFlow says requires installation.
How it compares
The one-panel DELTA Pro 3 kit against the station alone and two other solar bundles we review. Figures are from each maker's page.
| Spec | EcoFlow DELTA Pro 3 + 400W | EcoFlow DELTA Pro 3 (no panel) | Anker SOLIX F3800 Plus + 400W | Jackery Solar Generator 2000 v2 |
|---|---|---|---|---|
| Battery | 4,096 Wh | 4,096 Wh | 3,840 Wh | 2,042 Wh |
| Panel included | 1 × 400 W | None | 1 × 400 W bifacial | 2 × 200 W bifacial |
| Station solar ceiling | 2,600 W | 2,600 W | 3,200 W | 400 W |
| Share of ceiling used | About 15% | 0% | About 13% | 100% |
| 240 V output | Yes | Yes | Yes | No |
Using it in a long outage
What one 400 W panel delivers
Assume about 4 peak sun hours on a clear day in much of the US, fewer in winter or cloud (our planning assumption; check your own location). 400 W × 4 hours is 1,600 Wh at the panel. After losses from heat, angle and charging, call it about 1,200 Wh into the battery. A refrigerator rated at 400 kWh a year uses about 1,100 Wh a day, so on a clear day the panel roughly covers the fridge. Everything else, from the furnace blower to a well pump cycle, comes out of the battery.
With about 3,480 Wh usable from the battery (85% of 4,096 Wh, our planning figure), a fridge plus 300 Wh of lights, router and phones draws about 1,400 Wh a day. With the panel covering most of that on clear days, the battery drops slowly and lasts well past a week of good weather. Add a 240 V well pump or air conditioner and the drain rises fast; a second 400 W panel doubles the daily solar figure.
| Panels | Solar into battery, clear day | Covers |
|---|---|---|
| 1 × 400 W (this kit) | About 1,200 Wh | A typical fridge |
| 2 × 400 W | About 2,400 Wh | Fridge, freezer and small loads |
| 6 × 400 W (near the 2,600 W ceiling) | About 7,200 Wh | Refills the base battery plus daily loads |
Daily solar routine
- 01Set the panel out by mid-morning and set the stand between 40 and 80 degrees to face the sun.
- 02Keep the panel clear of shade; partial shade cuts output sharply.
- 03Keep the station indoors and dry, and run the cable through a door or window gap.
- 04Run the fridge, laundry and pump refills at midday while the panel is producing.
- 05Fold the panel away at night and before high wind.
Frequently asked questions
- How long does one 400W panel take to charge the DELTA Pro 3?
- On our planning math, one 400 W panel puts about 1,200 Wh into the battery on a clear day, so refilling 4,096 Wh from empty takes about three to four clear days with no load running. More panels shorten that; the station accepts up to 2,600 W.
- Will the DELTA Pro 3 with one panel keep a refrigerator running?
- Yes, in most clear-weather conditions. The panel roughly covers a typical fridge's daily use, and the 4,096 Wh battery carries the fridge through nights and cloudy days.
- Can I add more panels later?
- Yes. The station takes 1,600 W on its high-voltage input and 1,000 W on its low-voltage input, 2,600 W in total. EcoFlow also sells the kit with two 400 W panels.
- Can the 400W panel stay out in the rain?
- EcoFlow lists it as IP68. Bring it in during high wind, since a folding panel on a stand can be blown over.
- Did you test the DELTA Pro 3 solar kit?
- No. This is a research-based review, based on manufacturer specs and published data from Ready.gov, CDC and CPSC. We do not test products.
Sources
- EcoFlow, DELTA Pro 3 Solar Generator: kit options and specs, checked November 1, 2026.
- EcoFlow, 400W Portable Solar Panel, checked November 1, 2026.
- Ready.gov (FEMA), Power Outages, updated June 4, 2026.
- CDC, About Carbon Monoxide Poisoning, reviewed October 2026.
- U.S. Consumer Product Safety Commission, Carbon Monoxide Information Center, accessed October 27, 2026.
This is a research-based review. PowerLockdown does not test products; specs come from the manufacturer and safety guidance from the public agencies cited. See our editorial policy.
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