Best Portable Solar Panels and Solar Battery Chargers, Tested and Reviewed

The answer comes down to wattage. Portable solar devices range widely in the amount of power they can produce, which is largely a function of panel size. Bigger tends to mean more powerful in the world of solar.

The most compact and lightweight solar battery chargers typically produce somewhere between 15 and 50 watts of max power. Devices in this wattage range are best suited for charging personal electronic devices, like cell phones, Bluetooth speakers, smartwatches, GPS devices, or small external power banks to top off a phone battery. These devices may be a good fit for a backpacker or hiker, but not for a power outage at home.

Portable solar panels with a higher power output—often 100, 200, or even 400 watts of max power—are also available. These products tend to be heavier and bulkier, so they aren’t a good fit for hikers. But they work well at a tent or an RV campsite, during a tailgate, or on a boat. They can also be useful at home during a power outage by adding juice to a portable power station. Those large batteries can handle the higher output from the panel, store that energy, and then use it to power whatever device or appliance you plug into it. Many higher-power panels can be daisy-chained together for higher outputs.

A final note on wattage: The wattage listed by the manufacturer is the maximum under ideal conditions—but don’t expect those conditions all the time. Some unavoidable factors can substantially affect power output, including cloud cover and the angle of the sun. It’s not uncommon to get only half of the wattage listed by the manufacturer, so it may be useful to buy a more powerful device to compensate.

Portability: All these products are mobile, but their weight and dimensions range widely. Do you plan to store the solar panel in your garage, only to pull it out for an annual car-camping trip—or are you carrying the device for miles? The petite BigBlue 14W Solar Battery Charger is the lightest in our ratings and weighs just under 1 pound, while the heftiest portable solar panel in our ratings, the Goal Zero Boulder 200 Briefcase 200W Solar Panel, weighs in at 42 pounds. Certain models come with handles and are designed to fold up more efficiently.

Ports: The number and types of ports on the device will affect what you can charge and how fast you can charge. Most lower-wattage devices come with USB-A or faster-charging USB-C ports, allowing you to plug the panel directly into a smartphone or a small power bank with familiar charging accessories. The larger panels are likely to also offer a DC output for the quicker transfer of more power to a range of devices, including portable power stations.

Charging time: These devices don’t provide the kind of lightning-fast charging power that you get from a wall outlet, so temper your expectations. Even 100-watt portable solar panels can require hours of direct sunlight to charge a small power bank or a cell phone with a drained battery. This is also why an external battery is likely a necessary partner to a portable solar device. When it’s sunny and you have time, the panels can charge the external battery, so you can access that stored power whenever you need it most.

Angle to the sun: You can optimize a solar panel’s power output by angling it directly toward the sun, which is why some models offer convenient adjustable kickstands. If you’re using a solar panel that lies flat, you can try to prop it up on something else to get a better angle.

Weather and climate: While the panels can produce power on cloudy days, more direct sunshine correlates to more power. So it’s worth remembering that a hiker in sunny Arizona will get more power out of a portable solar panel than a hiker in New England on an overcast winter’s day.

This roundup of our highest-rated solar devices includes both the solar battery chargers and portable solar panels that CR recommends.