The peak watt figure is a bench value, not a field promise · review
The highest stated efficiency in this group at 25.4 per cent, from N-type cells on a shadow-free face — and the only listing here that says outright it will not charge a laptop or a power station.
A 28 W high-efficiency solar panel charger with dual USB-C and USB-A.
BigBlue states 20 per cent more power from every ray thanks to a shadow-free surface with no metal lines on the front panel, with engineered heat resistance and advanced N-type cells for low-light efficiency; dual USB-C and one USB-A at 5 V/3 A each, collectively 5 V/4.8 A, with no ability to store electricity; 25.4 per cent conversion and IP44 waterproofing with a polymer surface resisting rain, fog and wear, the USB junction box stated not waterproof; folding to 11 × 6 × 1.4 inches at 1.5 lbs; charging for smartphones, power banks, GPS and small electronics with intelligent safety charging; a package of panel, a 50 cm (19.7 in) USB-C to USB-C cable, carabiners and a manual, with advice against use inside a window or windscreen and an LED glowing solid blue when charging properly; and two notes — that the panel has no internal battery and needs direct sunlight, and that its output is not sufficient for laptops or large power stations, and that devices should be kept in the shade while charging.
No test conditions. No unfolded size. No kickstand.
The highest figure in this group.
Published as a conversion rate, which is the right way to state it. Two other panels here publish 24 per cent the same way. The fourth publishes a 24 per cent increase over traditional cells, which is not the same claim.
What efficiency buys is area: 28 watts from a panel folding to 11 by 6 inches at 671 grams is a good ratio, and this shelf’s introduction says cell type and efficiency tell you how much panel you carry for each watt.
N-type cells and a face with no metal lines are the two reasons the listing gives.
Twice, in its own notes.
“Its power output is not sufficient for charging laptops or large power stations.”
Five volts at 4.8 amps is 24 watts across three sockets, and a laptop wants a Power Delivery profile at 15 or 20 volts. This shelf’s introduction draws exactly this line — a USB-C socket advertising a Power Delivery profile against one that is a 5-volt port with a modern plug.
These are the second kind, and the listing does not pretend otherwise.
The lowest rating in this group.
Splashing water, and solid objects over a millimeter. The two FlexSolar panels here publish IP67.
And the USB junction box is not waterproof on top of that — which the introduction above predicts for every panel on this shelf.
A shower is survivable. A downpour is not, and the panel has to be out in the sun all day.
The note nobody else makes.
Direct sunlight and high temperatures trigger a phone’s own thermal protection, which slows or stops charging. So the panel goes in the sun and the device does not.
It is the kind of sentence that only comes from having been asked the question, and it is more useful than the efficiency figure above it.
BigBlue’s instructions carry the ports and the ingress rating. Nothing here replaces them, and nothing on this page describes any product as safe.
The American Amazon store was listing it at about $75 at the time of writing.
Every figure here is what Keepa held on the day this page was last revised. Offers and prices shift without warning.
Prices quoted in this text were read on October 8, 2026. The live price is at the top of the page.
| Stated peak output | 28 W |
|---|---|
| Test conditions stated | Not published |
| Cell type | Advanced N-type solar cells on a shadow-free surface with no metal lines on the front panel, stated for superior low-light efficiency |
| Stated efficiency | 25.4 per cent — the highest figure published in this group |
| Port set | Three: two USB-C and one USB-A, each at 5 V / 3 A maximum, collectively 5 V / 4.8 A |
| Power Delivery profiles | None published. The USB-C ports are rated 5 V / 3 A, which is not a Power Delivery profile |
| Controller included | No. The listing states no internal battery and no ability to store electricity |
| Folded dimensions | 11 × 6 × 1.4 in |
| Unfolded dimensions | Not published |
| Weight | 1.5 lbs — about 671 g (23.7 oz) |
| IP rating | IP44, with the USB junction box stated not waterproof |
| Amazon reference | B01EXWCPLC |
| EAN | 0768390608519 |
Because 5 volts at 4.8 amps is 24 watts spread across three sockets, and a laptop wants a Power Delivery profile at 15 or 20 volts. The listing puts it in its own note rather than leaving it to be discovered: "Its power output is not sufficient for charging laptops or large power stations." That is the distinction this shelf's introduction draws between a USB-C socket advertising a Power Delivery profile and one that is simply a 5-volt port with a modern plug — and this panel’s USB-C sockets are the second kind.
It is the highest figure in this group and it is published as a conversion rate, which is the right way to state it. Two other panels here publish 24 per cent the same way; the fourth publishes a 24 per cent increase over traditional cells, which is a different claim entirely. What efficiency buys is area: 28 watts from a panel folding to 11 by 6 inches at 671 grams is a good ratio, and this shelf's introduction says cell type and efficiency are what tell you how much panel you carry for each watt. N-type cells and a face with no metal lines are the two reasons the listing gives.
Splashing water from any direction, and solid objects over a millimeter. It is the lowest code in this group — the two FlexSolar panels publish IP67 — and the USB junction box is stated not waterproof on top of that. In practice a shower is survivable and a downpour is not, which for a panel that has to be out in the sun all day is the figure to weigh against the efficiency. The listing is at least consistent: it also advises against window and windscreen use, and against leaving devices in the sun.
Close prices, same category: comparable camping gear. We keep only the specifications all of them publish, because a column with gaps compares nothing.
| Model | Price | Stated peak output | Test conditions stated | Cell type | Stated efficiency |
|---|---|---|---|---|---|
| BigBlue BB 401 28 W charger | $75 | 28 W | Not published | Advanced N-type solar cells on a shadow-free surface with no metal lines on the front panel, stated for superior low-light efficiency | 25.4 per cent — the highest figure published in this group |
| FlexSolar FLC-E6 40 W panel | $57 | 40 W, with the 19 V DC port rated at 40 W maximum | Not published | Advanced monocrystalline cells with ETFE laminate coating | 24 per cent solar conversion rate |
| FlexSolar E 10 W folding panel | $25 | 10 W maximum under direct sunlight | Not published — as on all four panels in this group | High-efficiency monocrystalline A+ cells with ETFE film lamination | 24 per cent energy conversion rate |
| ELECOM NESTOUT 28 W, 4 panels | $130 | 28 W of power generation, across four panels | Not published | SunPower MAXEON cells, named by maker and series | Not published as an efficiency. The listing states "up to a 24% increase in efficiency compared to traditional solar cells", which is an increase and not a conversion rate |
Three phones at once, and nothing bigger
Amazon reports what buyers took in the month before this page was last checked: at least 500.
The figure is a floor, rounded by Amazon, and read through Keepa — it says what buyers picked, not what a maker claims.
Specifications: the manufacturer sheet for camping and hiking gear and the matching Amazon product page. Prices and availability: Keepa. Every figure on this page names its source.
28 W · SunPower MAXEON cells, "24% increase" not 24% efficiency · 2 stands · dual USB-A
The only panel in this group with adjustable stands and a current checker — and the only one whose twenty-four per cent is an increase over other cells rather than an efficiency.
Best for: A pitch where the panel is set up, angled and left for the day
≈ $130
40 W · QC3.0 USB-A + PD2.0 USB-C 18 W each + 19 V DC 40 W · IP67 · 800 g (28.2 oz)
The only panel in this group with three kinds of output and a Power Delivery profile — forty watts through a 19-volt DC port, or eighteen each through USB-C and USB-A.
Best for: A small power station and a phone from the same panel
≈ $57
10 W · 24% monocrystalline · IP67, junction box excluded · 300 g (10.6 oz) · USB-A only
The smallest and lightest panel in this group — ten watts in three hundred grams — with a 24 per cent cell efficiency, an IP67 face and a single USB-A socket.
Best for: A phone and a head torch on a multi-day walk, and nothing larger
≈ $25
