Two PV panels for sale can both say 100 W and still behave like different products once the voltage, size, laminate and connector are read.
When you shop PV panels for sale, read the STC line (Vmp, Imp, Voc and Isc) before the wattage, check Voc against your controller, measure the outline and weight, match the front sheet to exposure and confirm the connector. Single stock units prove a design, while bulk and custom orders run on a written specification agreed before production.
The sections below explain what the numbers on a listing mean, which build details set where a panel can go, and an eight-step check to run on any listing. They then cover what listings leave out, compare LinkSolar's stock panels in one spec table and lay out the bulk and custom route. LinkSolar's range runs from 0.11 W mini panels up to ETFE flexible solar panels from 50 W to 135 W, sized for devices, vehicles, boats and products, with rooftop home arrays outside its scope.
What do the numbers on a PV panel listing actually mean?
A PV panel is a set of photovoltaic cells wired in series and parallel and sealed behind a front sheet, rated by the power it makes under standard test conditions. One silicon cell gives about 0.5 to 0.6 V under load whatever its size, so the cell count sets the panel's voltage and the cell size sets its current. Every electrical figure on a listing follows from those two choices.
Standard test conditions (STC) mean 1000 W/m² of light, an AM1.5 spectrum and a cell temperature of 25 °C. According to PVEducation's page on nominal operating cell temperature, a module is rated at 25 °C under 1 kW/m² but in the field runs hotter and under less light, which is why the NOCT test uses 800 W/m², 20 °C air and 1 m/s wind. STC works like a fuel-economy test cycle: every panel runs the same lab test, so listings compare fairly, while the sun, heat and angle at your site set the output you actually get.
Four figures sit under the rated watts, and each one does a different job. According to PVEducation's explanation of the I-V curve, a panel delivers its maximum power at one point on that curve, where the voltage is Vmp and the current is Imp. The 100 W ETFE flexible panel in the LinkSolar range reads like this at STC:
- Vmp 18.05 V. The maximum power voltage is the working voltage the panel holds while it delivers its rated output.
- Imp 5.72 A. The maximum power current is the working current at that same point on the curve.
- Voc 21.63 V. The open-circuit voltage is the no-load voltage, and it is the highest figure your charge controller input has to tolerate.
- Isc 6.17 A. The short-circuit current is the most current the panel can push, and it is the number used to size fuses and wire.
A panel sold as "12 V" typically has a Vmp around 17 to 18 V and a Voc around 21 to 22 V, so the 100 W panel sits in that class. The "12 V" label names the battery the panel charges through a controller, while Vmp and Voc describe what the panel itself puts out.
Which build details on a PV panel listing decide where it can go?
A PV panel's cell type, outline and weight, front sheet and frame, and connector decide where it can be mounted and what it can plug into. The wattage tells you how much power to expect once the panel is in place. Read them first, because any one can rule a panel out.
Cell type
Crystalline silicon cells, whether mono, PERC or back-contact, typically give the most watts per area of panel. Thin-film amorphous silicon trades area efficiency for steadier output in shade and indoor light and for the ability to bend. LinkSolar's amorphous flexible cells, for example, run from 0.3 W to 1.5 W at 1.5 V Vmp and 2.0 V Voc.
If you plan to wire your own panel, loose solar cells for building your own string let you set the voltage with the cell count.
Front sheet, frame and weight
Framed glass panels suit fixed, rigid mounts. A frameless flexible panel laminated behind an ETFE front sheet weighs roughly a fifth of a glass module of the same output, so it can sit on a boat deck, a vehicle roof or a product housing. Compare flexible versus framed rigid panels.
The front sheet sets how long the panel lasts outdoors. ETFE handles UV best but costs more, PET costs less but starts to yellow after about two to three years outside, and glass lasts longest but adds weight.
Crystalline flexible panels follow gentle curves only and should not be folded sharply. Panels that roll up like a mat use thin-film cells, so a listing that says "fully flexible" but shows crystalline cells is using the phrase loosely.
Connector
The connector tells you what a PV panel plugs into without adapters. LinkSolar's stock range uses four types.
- MC4: The 50 W, 100 W and 135 W flexible panels ship with MC4 connectors and extension leads.
- 5.5 × 2.1 mm DC jack: The 12 W and 25 W mini power boxes deliver a regulated 5, 6, 9 or 12 V output through this plug.
- USB: The 11 W foldable panel charges devices at 5 V and 2.4 A.
- Solder pads: The 2.1 W bar and the 2.3 W glass mini panel carry two copper pads for wiring straight into a circuit board.
Whatever the connector, check that panel voltage and connector type fit the charge controller or power station input and stay within its maximum input rating.
How do you check a PV panel listing before you buy, step by step?
A PV panel listing check runs in a fixed order: the STC figures first, then voltage against your controller, then current, size, front sheet, connector and documents. Each step can rule a panel out, so a failed step ends the check for that listing. The same eight steps apply to a single stock panel and to the first unit of a planned bulk order.
- Find the STC line on the listing. If it shows only the rated watts, ask the seller for Vmp, Imp, Voc and Isc before going further.
- Match Vmp to the battery or device you plan to charge. An 18 V class panel, with a Vmp typically around 17 to 18 V, charges a 12 V battery through a controller, while a 5 to 6 V panel suits USB devices or single-cell lithium.
- Check Voc against the controller's maximum input voltage with a margin for cold mornings, because according to PVEducation open-circuit voltage falls about 2.2 mV/°C per silicon cell as temperature rises and climbs back as the cell cools. The 135 W flexible panel reaches about 30 V open circuit, above the input window of some small PWM controllers that handle the 100 W panel, and the difference is explained in how MPPT and PWM controllers treat panel voltage.
- Compare Imp and Isc with the controller's current rating. Use Isc, the most current the panel can push, to size the wire and the fuse.
- Measure the mounting area in millimeters and check the listed weight. On a deck or roof, the outline usually rules a panel out before the power does.
- Pick the front sheet by exposure. ETFE suits years outdoors, PET suits sheltered or short-life products, and tempered glass suits abrasion or a rigid flat face.
- Confirm that the connector type fits the controller or power station input. Measure the cable run as well, since longer cables add voltage drop.
- Ask for the datasheet with full I-V figures before you place a bulk order. Test one unit against that datasheet, following the method in testing a sample before a bulk order.
LinkSolar's mini panel pages publish open-circuit voltage, short-circuit current, maximum-power voltage and current, dimensions and lead type for each panel, which is the minimum a PV panel listing should show. Datasheets with full I-V figures are available on request, and the same figures are used when a custom version is quoted.
What do PV panels for sale listings leave out, and does new, used or bulk change that?
Most PV panels for sale listings leave out four things: output in the field, the Voc margin on cold mornings, which cells are inside, and how the edges and connectors hold up over time. New, used and bulk buyers each close those gaps with a different check. The rated wattage alone answers none of them.
New single units
A new panel sold from stock usually comes with published figures, so the listing is the specification you buy against. Read it with the eight-step check above, starting with the STC line and the Voc against your controller input. If Vmp, Imp, Voc or Isc are missing, ask for the datasheet before you order.
Used panels
A used panel's output depends on how it was stored and how long it sat outdoors, so the original listing figures no longer describe it. A used panel test and a close look at the laminate carry more weight than the label. Typical buyer checks cover four points:
- Electrical test. Ask for a recent I-V test, or at least a measured Voc and Isc, and compare the readings with the original rating.
- Cells and back sheet. Look for cracks, browning or bubbles across the cells and on the back of the panel.
- Edges. Check for edge lift or delamination, which lets moisture reach the cells, and read why laminated panels peel at the edges for the causes.
- Connector. Confirm the connector still mates firmly and the cable jacket shows no cracks.
Bulk orders
On a bulk order, cell type and brand vary by model and project requirements, so LinkSolar confirms what goes into each build in writing before the order. That written specification covers dimensions, Vmp, Imp, lamination, connector and tolerances, and shipped goods are inspected against it. For panels going into a product you sell, ask the supplier for its test report.
Buyers who wire their own strings from loose cells face a separate question about which cell bin they receive, covered in volume tiers and bin spread for loose cells. For finished panels, the written specification is the document that fixes field-relevant figures such as Vmp, Imp and connector type before production starts.
Specs to compare before you order: which LinkSolar PV panel family fits?
LinkSolar's PV panels for sale fall into four families: flexible ETFE panels, mini panels and mini power boxes, a foldable USB panel, and custom builds. The table below compares the stock panels on the figures explained in the first section.
| Panel | Rated W (STC) | Vmp / Voc | Imp or output | Size / weight | Front / build | Connector |
|---|---|---|---|---|---|---|
| 5 V mini panel | 0.11 W | 5 V / see product page | 22 mA | 35 × 22 mm | ETFE | See product page |
| 18 V mini bar | 2.1 W | 18 V rated / see product page | See product page | 247 × 44.5 mm, about 26 g | ETFE, back-contact cells on PCB | Solder pads |
| 5.5 V glass mini panel | 2.3 W | 5.5 V nominal / see product page | See product page | 113 × 113 mm | Tempered glass | Solder pads |
| 12 W mini power box | 12 W | 6.5 V / 7.2 V | Regulated 5, 6, 9 or 12 V, 12 V at 1 A | About 0.85 kg without batteries | IP66 housing | 5.5 × 2.1 mm DC |
| 25 W mini power box with MPPT | 25 W | About 17.5 V / about 21 V | Regulated 5, 6, 9 or 12 V | About 1.25 kg without batteries | IP66 housing | 5.5 × 2.1 mm DC |
| 11 W foldable panel | 11 W | 5.5 V max working / 6.5 V open | USB 5 V, 2.4 A | 245 × 315 mm open, 198 g | Foldable | USB |
| 100 W flexible panel | 100 W | 18.05 V / 21.63 V | 5.72 A | 1247 × 418 mm, 1.0 kg | ETFE, frameless | MC4 |
| 135 W flexible panel | 135 W | About 19 to 20 V / about 26 to 30 V | About 6.7 to 7.2 A | 545 × 1180 to 1374 mm, 1.8 to 2.0 kg | ETFE, frameless | MC4 |
Pick the row whose Voc and connector already fit your controller, then open that family's page for the full I-V figures: small PV panels from 0.1 W to 25 W, flexible PV panels with MC4 leads or foldable panels with a USB output.
Figures from the LinkSolar catalogue export of 23 September 2026 and the live pages on 25 September 2026. STC: 1000 W/m², AM1.5, 25 °C.
The mini bars and glass panels end in solder pads for wiring into a product. The two power boxes regulate their output to 5, 6, 9 or 12 V, and the 2.1 W bar's 18 V rating still has to be checked against the load.
The flexible panels are frameless ETFE modules for vehicles, boats and curved decks. The 135 W reaches about 30 V open circuit, which is above the input window of some small PWM controllers that handle the 100 W.
The 11 W foldable panel charges phones and small devices from its USB 5 V port. It is not designed for electricity storage, so the device holds the charge.
Custom builds change the outline, voltage, front sheet or connector when no stock row fits, as the next section covers. Full-size rooftop modules, typically well above 300 W, are a separate category LinkSolar does not list.
When should you buy PV panels wholesale or have them built to order?
A PV panel buyer should order stock single units to prove the design, move to a wholesale order of the same stock panel once the figures work in the product, and go custom when the outline, voltage or connector has to change. A wholesale order of a stock panel keeps the figures published on its product page, so the checks you ran on single units still apply. Before you compare offers, read what a wholesale quote for 100 W flexible panels should contain.
Custom builds through panels built to your outline and voltage cover voltages from 3 V to 48 V, with the cell count set by the target Vmp. Lamination can be PET, ETFE or fibreglass, or glass where rigidity matters. On the flexible side, custom flexible panels sized to a curved surface are specified in length and width to the millimetre at 12 V, 24 V, 36 V or a custom Vmp, with MC4, SAE or Anderson leads.
Most small-device buyers ask for a 5 V or 6 V direct output, because it lets the product skip a DC-DC converter and the losses that come with it. LinkSolar lists custom mini panels with 5 V or 6 V direct output for that case.
A custom quote starts from five items in the first message.
- Outline. Send a drawing or the surface dimensions in millimetres.
- Target voltage and load. State the battery or device voltage and the current the load draws.
- Lamination by exposure. Say whether the panel sits outdoors for years, stays sheltered or faces abrasion.
- Connector and exit side. Name the plug or lead type and whether the exit sits at the front, rear or side.
- Target quantity. Give the quantity the quote should be priced at.
LinkSolar works as a sourcing partner with factory-side QA, and LinkSolar's partner factories build to a written specification covering dimensions, Vmp, Imp, lamination, connector and tolerances. That specification is agreed before production, production is checked with EL imaging and IV curve testing, and shipped goods are inspected against it. To weigh any supplier's claims about its own production, use the checks that tell a manufacturer from a reseller.
FAQ: buying PV panels
What does PV mean on a solar panel listing?
PV stands for photovoltaic, the process in which cells turn light directly into DC electricity. A PV panel is a set of those cells wired in series and parallel, sealed behind a front sheet and rated at standard test conditions.
On a listing, the PV label tells you the product makes electricity from light, and the Vmp, Imp, Voc and Isc figures tell you what it can power.
Is a higher-watt PV panel always better?
A higher-watt PV panel is the better choice only when its open-circuit voltage, outline and connector also fit the system. The 135 W flexible panel, for example, reaches about 30 V open circuit, which is above the input window of some small PWM controllers that handle the 100 W version.
Check the controller's maximum input voltage and measure the mounting surface before you compare watts.
Are used PV panels worth buying?
Used PV panels can be worth buying when a recent I-V test or a measured Voc and Isc matches the original label. Before paying, check the back and edges for cracks, browning, bubbles or delamination.
Also confirm that the connector is intact and still mates with your cables and controller input.
Can I buy PV panels wholesale in small quantities?
LinkSolar sells its stock PV panels as single units, so a buyer can prove a design with one panel before ordering more. Wholesale quotes are priced at the quantity the buyer sends, for the same stock panel or for a custom build.
Include the panel family, target voltage and quantity in the enquiry so the quote matches the order.
Next step
Read Voc and the connector first, buy stock units to prove a design, and move to a custom build when the outline or voltage has to change. Send the outline drawing, target voltage, load and quantity, and request a quote against a written specification.
For stock panels, compare the figures in the small panel range with published I-V figures before you order.