The peak watt figure is a bench value, not a field promise · review
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.
A 40 W foldable solar panel charger with USB-C, USB-A and DC outputs.
FlexSolar states QC3.0 USB-A and PD2.0 USB-C ports at 18 W maximum each for simultaneous charging of phones, tablets and power banks, with a 19 V DC port at 40 W maximum to power small stations, a smart load distribution design recommending single-port use for peak efficiency, and no energy storage; an integrated IC detecting connected devices with an LED status light and overcurrent, overheating and short-circuit protection; folded dimensions of 8.0 × 11.1 × 1.8 inches at 1.76 lbs (0.8 kg (1.8 lb)); advanced monocrystalline cells at 24 per cent conversion with IP67 dustproof and waterproof construction and ETFE laminate, the junction box stated not fully waterproof and the panel not to be submerged for over 30 minutes; and a package of one panel, two carabiners and a manual, with the advice to position at 45° facing direct sunlight and a note that shade or partial coverage may reduce performance by up to 70 per cent.
No unfolded dimensions. No test conditions. No kickstand.
The DC port, and only that one.
The two USB sockets are eighteen watts each. The headline forty belongs to the 19-volt barrel output that feeds a small power station.
Which is this shelf’s buying tip, exactly: confirm the lead in the box matches the input socket on the battery you already own, because a panel and a power station from different makers usually need an adapter neither supplies.
The listing also asks that one port be prioritized at a time — the honest way of saying three sockets share one panel.
The only Power Delivery profile in this group.
This shelf’s introduction draws the line: a USB-C socket advertising a Power Delivery profile charges a phone or a laptop directly, while a barrel output is aimed at one power station and needs the right lead.
Eighteen watts is the low end of PD — a laptop usually wants 45 or 65. So this panel charges phones and tablets over USB-C, and power stations over DC.
The cost of shade, published.
Partial coverage on a series-wired panel does not cost output in proportion to the area shaded: one shaded cell throttles the string behind it.
That is why the same bullet asks for 45 degrees facing direct sunlight — and why this shelf’s introduction makes the kickstand matter, since the angle you can set is what changes yield through the day.
This panel asks for an angle and supplies nothing to hold it at one.
The limit on the IP67.
Not to be submerged for over thirty minutes, and the junction box is not fully waterproof — store it indoors in heavy rain.
Two exclusions on one rating, both published. This shelf’s introduction predicted the second: an ingress rating usually covers the panel face while the junction pocket is rated separately or not at all.
FlexSolar’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 $57 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 | 40 W, with the 19 V DC port rated at 40 W maximum |
|---|---|
| Test conditions stated | Not published |
| Cell type | Advanced monocrystalline cells with ETFE laminate coating |
| Stated efficiency | 24 per cent solar conversion rate |
| Port set | Three: a QC3.0 USB-A and a PD2.0 USB-C at 18 W maximum each, plus a 19 V DC port at 40 W maximum. The only DC output in this group |
| Power Delivery profiles | PD2.0 on the USB-C port at up to 18 W. The only Power Delivery profile published in this group |
| Controller included | No. The listing states an instant energy conversion device with no energy storage |
| Folded dimensions | 8.0 × 11.1 × 1.8 in |
| Unfolded dimensions | Not published |
| Weight | 1.76 lbs — 0.8 kg (1.8 lb) |
| IP rating | IP67 with ETFE lamination, with the junction box stated not fully waterproof and the panel not to be submerged for over 30 minutes |
| Amazon reference | B09H6GGK55 |
| EAN | 0785249519352 |
The 19 V DC one, and only that one. The two USB sockets are 18 watts each, so the 40 W headline belongs to the barrel output that feeds a small power station — which is the compatibility question this shelf's buying tip is written for: confirm the lead in the box matches the input socket on the battery you already own, because a panel and a power station from different makers usually need an adapter neither one supplies. The listing also recommends prioritizing a single port at a time for peak efficiency, which is the honest way to say the three sockets share one panel.
A phone at full speed and a tablet at a reasonable one. This shelf's introduction draws the line: a USB-C socket advertising a Power Delivery profile charges a phone or a laptop directly, while a barrel output is aimed at one power station and needs the right lead. Eighteen watts is the lower end of Power Delivery — a laptop usually wants 45 or 65 — so the useful reading is that this panel charges phones and tablets over USB-C and power stations over DC. It is the only panel in this group with a PD profile at all.
Up to 70 per cent, by the listing’s own figure, and publishing it is rare. Partial coverage on a series-wired panel does not reduce output in proportion to the area shaded: one shaded cell throttles the string behind it. That is why the same bullet asks for 45 degrees facing direct sunlight, and why this shelf's introduction says the kickstand matters — the angle you can set is what actually changes yield through the day. This panel asks for an angle and supplies nothing to hold it at one.
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 |
|---|---|---|---|---|---|
| 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 |
| 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 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 |
A small power station and a phone from the same panel
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 · 25.4% N-type cells · two USB-C and one USB-A, 5 V/4.8 A total · IP44
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.
Best for: Three phones at once, and nothing bigger
≈ $75
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
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
