Home / Power and batteries

Small solar panels for keeping essential devices charged

By the Plain Prepper editors. Updated 2026-10-14.

We research products from makers' specs, manuals and safety agencies; we do not run hands-on tests. Links to Amazon may earn us a commission at no cost to you. How this works.

Quick answer

Choose a small solar panel by the input your device accepts, the output available at the port and the space you can expose to sunlight. Goal Zero Nomad 10 is a compact USB example; Nomad 20 adds a solar charging cable; Jackery SolarSaga 40 Air offers a larger panel with model-specific charging accessories. The panel's wattage is not necessarily its USB output. Pair solar collection with compatible stored power when you need charging after sunset.

Start with the charging port, then compare the panel rating

A small solar panel can help recharge portable electronics, but the label on the panel does not describe every output connector. These maker figures show why the distinction matters.

Example	Panel rating	Documented output path
Goal Zero Nomad 10	10 W	USB: 5 V, up to 1.5 A, 7.5 W maximum
Goal Zero Nomad 20	20 W	USB: 5 V, up to 2.1 A, 10.5 W maximum; separate solar cable
Jackery SolarSaga 40 Air JS-40B	40 W under standard test conditions, +/-5%	Multifunctional adapter: USB-A 5 V/2.4 A; USB-C 5 V/3 A

Goal Zero publishes the Nomad figures on the current product pages. The Jackery figures come from its U.S. JS-40B manual, which is reproduced on the retailer's document server. Match the model on the delivered panel and accessories before use.

Choose a charging task first: a headlamp, phone, power bank or compatible station. Check that device's accepted input and approved charging cable. A larger panel label cannot force the device to accept a higher charging rate.

Use volts times amps to understand the USB ceiling

The Nomad 10's USB maximum follows directly from 5 V multiplied by 1.5 A: 7.5 W. The Nomad 20's USB limit is 5 times 2.1, or 10.5 W. Doubling the panel rating therefore does not double the published USB-port ceiling.

For SolarSaga 40 Air, the manual's adapter figures calculate to 12 W at USB-A and 15 W at USB-C. They do not mean a phone receives the panel's entire 40 W rating through either port.

Do not add separate port maxima and assume they are guaranteed simultaneously. The available sunlight, device demand and accessory limits still apply. The cited Jackery USB specifications describe its multifunctional adapter, not permission to use any cable with a similar connector.

Compare these ceilings with the way you actually charge. A device that normally expects a different USB power profile needs its own compatibility check. The presence of USB-C identifies the connector style; the published voltage and current describe the supported output in this example.

Check folded storage and the open collection area

Goal Zero lists Nomad 10 at 1.12 lb, folding to 9.5 by 7.2 by 1.25 inches. Unfolded, it measures 9.5 by 14.5 by 0.75 inches. Nomad 20 is 2.28 lb, folding to 11.5 by 7.4 by 1.25 inches and opening to 11.5 by 21.75 by 0.75 inches.

Jackery's JS-40B manual lists about 1.98 lb and folded dimensions of 9.1 by 13.4 by 0.8 inches, excluding the junction box. Allow room for that box and the cable rather than treating the flat-panel dimension as the entire packed assembly.

Check both conditions: whether the folded panel fits your bag and whether the open panel can face unobstructed sun at the intended location. Goal Zero's examples have adjustable kickstands. Jackery's manual describes a sun-angle indicator and adjusting orientation as the sun moves.

Separate collecting sunlight from storing usable energy

The Department of Energy explains that photovoltaic cells convert absorbed light into electrical current. Their output depends on the light and the cell's performance. A panel is the collecting part of the system; an attached battery provides storage.

The Nomad manuals explicitly say these panels contain no built-in battery. Goal Zero permits direct USB charging or pairing with a compatible power bank for later use. That distinction matters when the charging task continues after the panel is packed away.

The Nomad manuals also describe phones stopping charging in low light. Their auto-restart feature is intended to resume charging after an environmental interruption. It does not supply energy through prolonged shade or darkness.

Start an outage plan with stored energy available, then treat the panel as a way to replenish it when conditions permit. Evaluate the device and power bank together during ordinary use. Do not infer a fixed number of phone refills from the panel wattage alone.

Match solar cables and avoid improvised panel chains

Nomad 20 has an integrated blue 8 mm solar output listed at 14 to 22 V, up to 1.3 A and 20 W maximum. That is distinct from its regulated USB output. Confirm the receiving station's solar-input limits and approved connection.

Goal Zero says Nomad 10 is not chainable. Nomad 20 permits specified Nomad combinations; its guide limits the chain and warns about losses through longer cable paths. Do not transfer that permission to unrelated panels or assume another similarly shaped plug is equivalent.

Jackery's manual says the included JS-40B cables are specific to SolarSaga 40 Air. Its DC8020-to-USB-C adapter cable is for charging Jackery stations only, not other devices. Ordinary USB device charging uses the separate multifunctional adapter outputs depicted in the manual.

Accessory lists also differ: the U.S. product page's box summary is shorter than the manual's full list, including the dedicated USB-C adapter cable. Confirm the supplied bundle rather than assuming every pictured adapter comes with every listing.

Follow weather limits and distinguish cell life from panel durability

Jackery advertises IP68 weather protection, but the same product page's FAQ says not to leave the panel in rain or soak it. It also says the station-adapter output ports are not waterproof. Follow those restrictions rather than interpreting the rating as permission to leave connected electronics exposed.

The JS-40B manual says the panel is not intended for permanent installation and should be stored during strong wind, hail or other severe weather. It prohibits bending, stepping on the panel, artificial spotlights and unprotected combinations with other power sources.

Goal Zero's English manuals describe Nomads as weatherproof, while its current product FAQ uses waterproof language. Keep receiving devices protected and avoid treating those words as a verified immersion specification.

DOE's discussion of long-lived silicon modules is about photovoltaic technology. It does not establish a service life for these folding products' fabric, hinges, connectors or accessories. Inspect the complete panel and cable assembly, and replace damaged parts according to the manufacturer.

What to look for when you buy

Questions people ask

How do small solar panels work?

DOE says photovoltaic material absorbs sunlight and converts its energy into electrical current. The panel supplies power while suitable light is available. A compatible battery stores energy for later use.

How many small solar panels do I need?

Start with the device's energy needs and the charging input it accepts. Then check available sun, storage and approved panel combinations. A universal panel count cannot be inferred from the nameplate wattage.

Does a 40 W solar panel charge a phone at 40 W?

Not through the documented SolarSaga 40 Air adapter outputs. Its U.S. manual lists USB-A at 5 V/2.4 A and USB-C at 5 V/3 A, equivalent to 12 W and 15 W maxima before actual conditions and device demand.

Can I leave a folding panel outside permanently?

Check its instructions. SolarSaga 40 Air's manual expressly says it is not for permanent installation, and the product FAQ restricts rain exposure. Protect connected batteries and devices rather than relying on a panel's weather label.

Sources

• Nomad 10 current specifications and FAQ, Goal Zero
• Nomad 20 current specifications and FAQ, Goal Zero
• SolarSaga 40 Air current U.S. page and weather FAQ, Jackery
• Nomad 10 SKU 11900 user guide, linked by current support, Goal Zero
• Nomad 20 SKU 11910 user guide, linked by current support, Goal Zero
• SolarSaga 40 Air JS-40B U.S. user manual, retailer-hosted original, Jackery, hosted by Home Depot
• Solar Photovoltaic Cell Basics, U.S. Department of Energy

Sources checked 2026-10-14.