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
4.2/5
For owners of large power stations who want 400 W from a single panel set up beside a car or RV. Check that your station’s solar input handles about 48 V first.
- 400 WRated output
- Not tested (estimated 87%)Tested output
- 30.2 lbWeight
- 47.2 VOpen-circuit voltage
- IP67Water resistance
- $1.24Price / W
Check price at Amazon$495.99Check price at Renogy$495.99
Price checked October 21, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- 400 W from one suitcase, so a single panel can feed a large power station’s solar input
- Aluminum kickstands angle it toward the sun without improvising
- Can be wired in series or parallel with more panels as the system grows
- 3-year warranty, longer than most portable panels
Cons
- About 30 lb and over 9 ft long unfolded, so it is a two-hand carry from the car, not a hiking panel
- 47.2 V open-circuit voltage needs a power station that accepts more than 48 V solar input
- MC4 output only, with no USB ports; the power-station adapter is sold separately, and there is no independent output test yet
How it scores
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.
Specifications
| Output | |
|---|---|
| Rated power | 400 W |
| Tested output | Not tested (estimated 87%) |
| Efficiency | 23% (cell efficiency per Renogy's product page and the Amazon listing; the product description elsewhere says 22.7%) |
| Cells | Monocrystalline |
| Bifacial | No |
| Electrical | |
| Open-circuit voltage (Voc) | 47.2 V |
| Voltage at max power (Vmp) | 40 V |
| Short-circuit current (Isc) | 11 A |
| Current at max power (Imp) | 10 A |
| Series / parallel | Yes |
| Connections | |
| Output connector | MC4 |
| USB ports | None |
| Build | |
| Weight | 30.2 lb (13.7 kg) |
| Folded size | 27.9 x 33.7 x 3.2 in (708 x 855 x 80 mm) |
| Unfolded size | 111.8 x 33.7 x 0.8 in (2838 x 855 x 20 mm) |
| Kickstand | Yes |
| Water resistance | IP67 |
| Warranty | 3 years |
Alternatives in this size
Renogy 400W N-Type Portable Solar Panel Blanket
#7 in LargeFull review
For van, truck and SUV campers who want 400 W from something that stows like a backpack. Owners of small power stations should check the voltage limit, and anyone who wants to prop a panel up on legs should look at a folding suitcase panel instead.
Amazon $469.99 Renogy $469.99$469.99
ALLPOWERS SP037 400W Foldable Solar Panel
#9 in LargeFull review
A cheap way to put 400 W into a large power station from a campsite or driveway, as long as you don’t need to carry it far. Hikers and small-station owners should look at lighter, lower-voltage panels.
Amazon $299 ALLPOWERS $299$299
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