The peak watt figure is a bench value, not a field promise · review
MARBERO 30 W folding panel, USB-C / QC3.0 USB-A / 16.5 V DC, 1.1 kg stated review
A 30 W panel built around a 16.5 V DC socket for a power station, and the only listing of the nine to print the voltage and current steps of every one of its outputs.
The bottom line The listing that tells you the most about its electricity and the least about its weatherproofing.
What this listing puts on record
A 30 W folding panel with three outputs — USB-C, a QC3.0 USB-A and a 16.5 V DC socket — a stated efficiency of 21.5 to 23.5 %, a folded size of 22.5 × 30.4 × 4.5 cm, a mass of 1.1 kg, a carry bag and a carry handle.
Built around the DC socket
The first bullet point is about solar generators, not about phones. DC adapter plugs are supplied in several sizes, the DC output is quoted at 16.5 V / 1.81 A maximum, and car fridges and air pumps are named as the sort of thing it is meant to run. The USB sockets follow afterwards. On a shelf where most listings lead with a phone, that ordering tells you who the panel is for.
An efficiency range rather than a figure
21.5 to 23.5 % is how the number is printed, and the listing never explains the two-point spread. Every other panel here gives one figure. None of them, this one included, gives an irradiance or a cell temperature, so all of these percentages rank panels against each other and predict nothing about a particular afternoon.
Nothing at all about weather
There is no IP figure anywhere on this listing. Not for the panel face, not for the socket pocket. Two of the nine panels on this shelf are in the same position; the other seven publish something. It is the one column where a listing this detailed goes completely quiet.
The battery is not included in the idea
The closing bullet point states it without ornament: the panel stores no electricity, and a power station or battery is required. That is the honest half. The other half is that no charge controller is named — here or on any listing in this hub — so the regulation between panel and battery is left for the battery to supply.
Availability
Selling between 44 € and 64 € across the German, French, Italian and Spanish Amazon stores when this page was checked.
It also sells on the American and British Amazon stores in the local currency, which the range above does not cover — that range counts euro stores and nothing else.
Every figure in this section is what Keepa returned on the day this page was last updated. Prices and offers change without notice.
Prices quoted in this text were read on 6 September 2026. The live price is at the top of the page.
What it does well, and where it gives way
Strengths
Publishes the voltage and current steps of both USB outputs and of the DC socket, which is more electrical detail than any other listing here offers
A folded size in three dimensions, a mass, a carry bag and a carry handle are all stated
Says outright that the panel stores nothing and that a power station or battery is required
Compromises
No cell type and no ingress rating at all, on a panel meant to be left out in the weather
The efficiency arrives as a two-point range with nothing to say what moves it between the ends
The words Power Delivery never appear, so the USB-C steps have to be read against your own device
Specifications
Stated peak output
30 W — stated in the title
Test conditions stated
Not published on the listing — no irradiance and no cell temperature accompany the 30 W
Cell type
Not published on the listing — the cells are called high-efficiency and are named neither monocrystalline nor polycrystalline
Stated efficiency
21.5 % to 23.5 % — stated as a range, and the only efficiency on this shelf given as a range rather than a single figure
Port set
Three outputs — USB-C, a QC3.0 USB-A and a DC socket — stated. USB-C at 5 V/3 A, 9 V/2.22 A and 12 V/1.67 A; QC3.0 USB-A at 5 V/3.4 A, 9 V/2.5 A and 12 V/2 A; DC at 16.5 V/1.81 A maximum
Power Delivery profiles
Not published on the listing as Power Delivery — the USB-C steps are given in full, and the words Power Delivery appear nowhere
Controller included
Not published on the listing — the maker states the panel stores nothing and that a power station or a battery is required
Folded dimensions
22.5 × 30.4 × 4.5 cm folded — stated
Unfolded dimensions
Not published on the listing
Weight
1.1 kg — stated
IP rating
Not published on the listing — no IP figure of any kind appears
Amazon reference
B092872NYT (same reference on 6 Amazon marketplaces)
EAN
0794590655480
What people ask before buying
Is the 16.5 V DC output the point of this panel?
The maker says so in its first bullet point: DC adapter plugs are supplied, the output is quoted at 16.5 V and 1.81 A maximum, and the panel is described as intended for solar generators and portable power stations. The USB sockets are the second argument here, which is the reverse of most of this shelf.
Why is the efficiency written as 21.5 to 23.5 %?
The listing gives it that way and never says what moves the figure between the two ends. It is the only efficiency on this shelf published as a range. Like every percentage here it comes without an irradiance or a cell temperature, so it ranks the panel and does not predict a yield.
SOLIX PS30 folding solar panel · 30 W stated · USB-A and USB-C · IP65 · two carabiners and an 18-month warranty · no size, mass or efficiency published
The emptiest specification of the nine: a 30 W folding panel with USB-A, USB-C and an IP65 rating, and no mass, no size, no cell type and no efficiency figure anywhere on the page.
Best for: A buyer choosing on the brand and the IP65, who does not need the panel compared with anything.
40 W folding solar module · XT60, USB-A and USB-C · 23 % efficiency stated · IPX4 · fold-out feet and a carry handle · XT60 and USB-C leads supplied · no size or mass published
A 40 W module sold first as an accessory to the maker's own battery power station, with an XT60 lead in the box, fold-out feet to aim it at the sun, and no dimension or mass published anywhere.
Best for: An owner of the maker's own battery power station, for whom the XT60 lead in the box settles the question.
15 W folding solar panel · three rubber-covered connectors · up to 24 % conversion stated · IP67 · 19.8 × 22.4 × 1.8 cm folded · 0.45 kg — the lightest published weight of the nine
The lightest and smallest panel of the nine at 0.45 kg and 19.8 × 22.4 × 1.8 cm folded, and also the lowest peak figure here at 15 W — the trade is written on the label.
Best for: A day pack where the panel has to disappear between uses and a phone is the only thing being charged.
