For owners of large EcoFlow DELTA-class stations who want the most watts from a single folding panel and will mostly set it up near the car. Campers who carry gear any distance are better off with two smaller panels.
Price checked October 21, 2026. As an Amazon Associate we earn from qualifying purchases.
The rating comes from 6 measured or published factors, each scored 0-100 against fixed reference points for its size. How we rank explains each one.
The most power independent reviewers measured from the panel in real sun. Heat, haze, sun angle and the device being charged all cut output, so 70-85% of the rated watts is a normal real-world result.
| Tested by | Measured peak | Of rated | Conditions |
|---|---|---|---|
| Mighty Gadget | 305 W | 76% | Highest input shown on an EcoFlow DELTA 2 after adjusting the angle, early afternoon in a partly shaded garden in the north of the UK, mixed sun and cloud, September 2022; input mostly settled between 150 and 250 W |
| Output | |
|---|---|
| Rated power | 400 W |
| Tested output | 305 W (76%) |
| Efficiency | 22.4% (22.40% in EcoFlow's spec table, cell or module not stated; the US product page says up to 23% and labels the option 22.6%) |
| Cells | Monocrystalline |
| Bifacial | No |
| Electrical | |
| Open-circuit voltage (Voc) | 48 V |
| Voltage at max power (Vmp) | 41 V |
| Short-circuit current (Isc) | 11 A |
| Current at max power (Imp) | 9.8 A |
| Series / parallel | Yes |
| Connections | |
| Output connector | MC4 |
| Cables included | MC4 to XT60 |
| USB ports | None |
| Build | |
| Weight | 35.3 lb (16 kg) |
| Unfolded size | 42.0 x 94.1 x 1.0 in |
| Kickstand | Yes |
| Water resistance | IP68 |
| Warranty | 1 years |
For owners of large BLUETTI or similar power stations who want maximum watts from one panel at a campsite or during an outage. The short warranty and high voltage rule it out for small stations.
Amazon $798.99 BLUETTI $849A low-cost all-in-one kit for keeping a 12 V RV, boat or camper battery topped up. Power-station owners are better served by a panel with published electrical specs.
Amazon $179.77For BLUETTI and other mid-size station owners who want lots of watts from one panel near the car. Hikers and anyone who moves it often should look at lighter panels.
BLUETTI $649Compare the EcoFlow 400W Portable Solar Panel with any other portable solar panel →
More from EcoFlow: every EcoFlow product ranked.
