TWELSEAVAN 400W Portable Solar Panel
#6 in LargeFull review
A 400 W folding panel for owners of large power stations that accept around 50 V of solar input. Small-station owners need a lower-voltage panel.
Amazon $399.99$399.99
The TWELSEAVAN 400W Portable Solar Panel is the better portable solar panel overall, rated 4.2 to 3.5. The TWELSEAVAN 400W Portable Solar Panel leads on value, portability and efficiency. The BLUETTI PV350 350W Portable Solar Panel wins on features. The TWELSEAVAN 400W Portable Solar Panel costs $249.01 less ($399.99 vs $649).
BLUETTI PV350 350W Portable Solar Panel
#13 in LargeFull review
For 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 $649$649
Prices 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.
Which should you buy?
- Choose the TWELSEAVAN 400W Portable Solar Panel for value ($1.00 per rated watt vs $1.85 per rated watt), portability (17.6 W per lb (22.7 lb (10.3 kg)) vs 10.8 W per lb (32.4 lb (14.7 kg))) and efficiency (24% claimed efficiency vs 23.4% claimed efficiency).
- Choose the BLUETTI PV350 350W Portable Solar Panel for features (built-in kickstand, series/parallel vs built-in kickstand).
Scores side by side
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 | TWELSEAVAN 400W Portable Solar Panel | BLUETTI PV350 350W Portable Solar Panel |
|---|---|---|
| Overall rating | 4.2/5 | 3.5/5 |
| Value 30% | 86 $1.00 per rated watt | 37 $1.85 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% | 97 17.6 W per lb (22.7 lb (10.3 kg)) | 40 10.8 W per lb (32.4 lb (14.7 kg)) |
| Durability 15% | 56 IP65, 2-year warranty | 60 IP67, 1-year warranty |
| Efficiency 10% | 83 24% claimed efficiency | 73 23.4% claimed efficiency |
| Features 10% | 35 built-in kickstand | 55 built-in kickstand, series/parallel |
Specifications
| TWELSEAVAN 400W Portable Solar Panel | BLUETTI PV350 350W Portable Solar Panel | |
|---|---|---|
| Output | ||
| Rated power | 400 W | 350 W |
| Tested output | Not tested (estimated 87%) | Not tested (estimated 87%) |
| Efficiency | 24% (cell efficiency per the Amazon listing) | 23.4% (cell efficiency ("up to"), per BLUETTI's manual) |
| Cells | Monocrystalline | - |
| Bifacial | No | No |
| Electrical | ||
| Open-circuit voltage (Voc) | 46.9 V | 44 V |
| Voltage at max power (Vmp) | 40 V | 37 V |
| Short-circuit current (Isc) | 10.6 A | 11.4 A |
| Current at max power (Imp) | 10 A | 9.5 A |
| Series / parallel | - | Yes |
| Connections | ||
| Output connector | MC4 | MC4 |
| Cables included | 9.8 ft 5-in-1 MC4 cable (Anderson, XT60, DC8020, DC7909, DC5521), 3 DC adapters | 1.5 m MC4 to XT60 (20 A) |
| Build | ||
| Weight | 22.7 lb (10.3 kg) | 32.4 lb (14.7 kg) |
| Folded size | 26 x 35.5 in | 29.3 x 30.9 x 2 in |
| Unfolded size | 35.5 x 98.5 in | 110.6 x 30.9 in |
| Folding sections | - | 4 |
| Kickstand | Yes | Yes |
| Water resistance | IP65 | IP67 |
| Warranty | 2 years | 1 years |