There’s no better charger than the sun—at least if you’re trekking in the middle of Montana and the next wall outlet is 30 miles away. The following solar chargers are portable, durable, and should provide enough juice to keep your gadgets going all day long. But keep in mind you’ll need bluebird skies and some extra time on your hands—solar charging can take up to 10 hours or more, even on a good day.
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Eton BoostSolar ($130)
ճ is the one you want for long treks. The solar panel measures about six inches square, and it’s only three-quarters of an inch thick. There’s a USB port that will fully charge a smartphone twice. On cloudy days at home, you can charge the BoostSolar using a standard micro-USB port plugged into a wall outlet. This solar charger has rubber bumpers for protection and takes about 30 hours to charge fully from the sun on a bright day.
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Goal Zero Nomad 7 ($80)
This relatively small solar panel is . Charge a headlamp all day in the sun, and you’ll be able to use the light all evening at your campsite. There’s no included battery pack, but Goal Zero makes several compatible add-on power packs, including the new ($40). The panels on the 13-ounce Nomad fold up like a book, making it extremely packable. To fully charge the power pack, you’ll need bright sunlight for about four hours.
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Aspect Solar Duo-Flex ($160)
Like the Goal Zero Nomad, the is a foldable solar panel that charges headlamps, smartphones, tablets, and other portable electronics that don’t require too much juice. The entire kit—which weighs just over a pound—includes a battery pack that takes 10 hours to charge by the sun. You can charge two gadgets at once with the power pack’s two USB ports, or charge continuously using only the panels. A headlamp can be fully charged up to three times. The best part? The Duo-Flex is rugged enough to withstand short drops and some serious jostling in your backpack. An included water-resistant case offers extra protection on rainy days.
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Bracketron Xolar3000 ($50)
Yes, this charger is designed for golf outings, but it works well on hikes, too. The combines a small solar charger and back-up battery. The solar panel is about the size of a smartphone, and the charger has one USB output. Charging the battery pack takes about eight hours of direct sunlight, and you’ll be able to charge a smartphone about two and a half times. Like most back-up batteries, you can also charge using a wall outlet or by plugging into a laptop’s USB port.
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Solarpod Buddy ($50)
Another solar charger designed to charge a smartphone, the is about the size of an iPhone. You’ll collect rays gradually—it takes about 17 hours for a full charge—but once you’re at 100 percent, you can expect to charge a smartphone twice or a digital camera about seven times. You can also charge from a wall outlet (that takes just over four hours). The Buddy isn’t water-resistant or super rugged, but it is made from a hard plastic and can withstand some abuse in your backpack.
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Cobra CPP 300 ($80)
Available this May, the new is a rugged, waterproof solar charger with a built-in battery pack. It comes with rubber bumpers on the side, and the panels fold out for a total solar-charging area about 11 inches wide and six inches tall—about double the size of most pocket chargers. Once you’ve “solared” up (which will take up to 15 hours), you can expect to charge your phone about three times.