The Greenmagic 400W Portable Foldable Solar Panel (GM400B) is the better portable solar panel overall, rated 4.3 to 4.0. The Greenmagic 400W Portable Foldable Solar Panel (GM400B) leads on features. The CTOLITY 400W Portable Solar Panel (400W-NEW) costs $33 less ($289.99 vs $322.99).
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 $322.99A low-priced 400 W folding panel, but its listing is too thin and inconsistent to recommend over better-documented panels until CTOLITY publishes full specs.
Amazon $289.99Prices 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) | CTOLITY 400W Portable Solar Panel (400W-NEW) |
|---|---|---|
| Overall rating | 4.3/5 | 4.0/5 |
| Value 30% | 97 $0.81 per rated watt | 100 $0.72 per rated watt |
| Tested output 20% | 89 not yet tested; estimated 87% of rated watts from the median of the 10 tested panels | 89 not yet tested; estimated 87% of rated watts from the median of the 10 tested panels |
| Portability 15% | 100 18.6 W per lb (21.5 lb (9.8 kg)) | 50 weight not published (neutral score used) |
| Durability 15% | 36 IP65 | 36 IP65 |
| Efficiency 10% | 75 23.5% claimed efficiency | 73 23.4% claimed efficiency |
| Features 10% | 55 built-in kickstand, series/parallel | 35 built-in kickstand |
| Greenmagic 400W Portable Foldable Solar Panel (GM400B) | CTOLITY 400W Portable Solar Panel (400W-NEW) | |
|---|---|---|
| Output | ||
| Rated power | 400 W | 400 W |
| Tested output | Not tested (estimated 87%) | Not tested (estimated 87%) |
| Efficiency | 23.5% (the listing gives a 21.5-23.5% range without saying cell or module; the top of the range is recorded) | 23.4% (conversion efficiency from the Amazon listing's description, not stated as cell or module; the listing title says 23%) |
| Cells | Monocrystalline | Monocrystalline |
| Bifacial | No | No |
| Electrical | ||
| Series / parallel | Yes | - |
| Connections | ||
| Output connector | MC4 | MC4 |
| USB ports | None | - |
| Build | ||
| Weight | 21.5 lb (9.8 kg) | - |
| Folded size | 32.09 x 31.30 x 1.97 in | - |
| Kickstand | Yes | Yes |
| Water resistance | IP65 | IP65 |
