The Greenmagic 400W Portable Foldable Solar Panel (GM400B) is the better portable solar panel overall, rated 4.3 to 3.3. The Greenmagic 400W Portable Foldable Solar Panel (GM400B) leads on value, portability and efficiency. The EcoFlow 400W Portable Solar Panel wins on durability. The Greenmagic 400W Portable Foldable Solar Panel (GM400B) costs $376.01 less ($322.99 vs $699).
A low-cost 400 W folding panel for owners of large power stations who camp by the car or RV. The thin spec sheet means checking a station’s voltage limit before buying.
Amazon $322.99For 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.
Amazon $699 EcoFlow $699Prices were last checked October 21, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Each factor is scored 0-100 against the same fixed reference points for every large portable solar panel; a clear win is highlighted. How we rank explains each one.
| Factor weight | Greenmagic 400W Portable Foldable Solar Panel (GM400B) | EcoFlow 400W Portable Solar Panel |
|---|---|---|
| Overall rating | 4.3/5 | 3.3/5 |
| Value 30% | 97 $0.81 per rated watt | 43 $1.75 per rated watt |
| Tested output 20% | 89 not yet tested; estimated 87% of rated watts from the median of the 10 tested panels | 54 best measured 76% of rated watts (1 test) |
| Portability 15% | 100 18.6 W per lb (21.5 lb (9.8 kg)) | 44 11.3 W per lb (35.3 lb (16 kg)) |
| Durability 15% | 36 IP65 | 60 IP68, 1-year warranty |
| Efficiency 10% | 75 23.5% claimed efficiency | 57 22.4% claimed efficiency |
| Features 10% | 55 built-in kickstand, series/parallel | 55 built-in kickstand, series/parallel |
No independent test published yet.
| 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 |
| Greenmagic 400W Portable Foldable Solar Panel (GM400B) | EcoFlow 400W Portable Solar Panel | |
|---|---|---|
| Output | ||
| Rated power | 400 W | 400 W |
| Tested output | Not tested (estimated 87%) | 305 W (76%) |
| Efficiency | 23.5% (the listing gives a 21.5-23.5% range without saying cell or module; the top of the range is recorded) | 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 | Monocrystalline |
| Bifacial | No | 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 | Yes |
| Connections | ||
| Output connector | MC4 | MC4 |
| Cables included | - | MC4 to XT60 |
| USB ports | None | None |
| Build | ||
| Weight | 21.5 lb (9.8 kg) | 35.3 lb (16 kg) |
| Folded size | 32.09 x 31.30 x 1.97 in | - |
| Unfolded size | - | 42.0 x 94.1 x 1.0 in |
| Kickstand | Yes | Yes |
| Water resistance | IP65 | IP68 |
| Warranty | - | 1 years |
