Solar chargers have come a long way thanks to new high-efficiency panels and rugged designs. We favor units with an onboard battery, which let us bank energy to use in driving rain, at night, and in emergencies; the ones we used for this test all charged their own lightweight lithium-ion in four to six hours of direct sunlight. These devices should always have a mini-USB connection to keep your phone, camera, or e-book topped off.
When shopping for a solar changer, keep in mind the two basic kinds of panels: rigid monocrystalline and the flexible thin-film. Your decision should be based on which kind will work best given the weather conditions in the areas where you like to explore. Rigid panels generate more electricity in bright sunlight, but most don’t generate much energy at all under clouds. Flexible thin-film panels are less efficient, but make more juice on cloudy days. They also roll up into a small package, which is great when you're traveling with a full pack.
Keep your eyes out for new developments. The field is evolving fast, and the prices and efficiency of thin-film roll-up panels are getting better all the time. After the jump, we run down the best new portable chargers available now and the most promising ones coming up.
The Best Rugged Solar Chargers: WakaWaka Power
Developed with the help of a Kickstarter campaign, this solar charger from the makers of the much-loved WakaWaka Solar Lamp is set to hit the streets in May 2013. With the WakaWaka Power, designers have created a combination light and charger for your phone, GPS, or camera. On a full charge, the device runs the light for 40 hours or recharges a depleted phone. Its status lights and efficient solar cells make it great for the outdoors. The downside: It's the only unit in this round-up that's not water-resistant.
WEIGHT: 7 ounces
SIZE: 4.7 x 0.6 x 3 inches
The Best Rugged Solar Chargers: Joos Orange
The Joos Orange is the most trusted small charger for challenging outdoor conditions. It’s shockproof and fully submersible. The manufacturer (pronounced “juice”) has even shot it with a .22 rifle to prove its dependability (though we’re hoping that isn’t a feature you need). It has a built-in loop that lets you hang it off a carabiner and a monocrystalline panel that charges better in cloud cover than other rigid panels. The unit also has the biggest battery, which is handy when you're traveling with multiple devices, but makes the unit a tad heavy.
WEIGHT: 1.5 pounds
SIZE: 8.6 x 5.8 x 0.8 inches
The Best Rugged Solar Chargers: Powertraveler Solarmonkey Adventurer
The Adventurer comes with its own nylon case with waterproof zippers, spare pockets, and a carabiner for hanging it from backpack loops. Though the electronics aren’t waterproof, the pouch protects them from splashes when stowed and features an insulated shell to prevent battery drain in cold conditions. Powertraveler, which is based in the U.K., sells its products in the U.S. through Amazon.
WEIGHT: 9.3 ounces
SIZE: 6.7 x 3.8 x 0.9 inches
The Best Rugged Solar Chargers: Bushnell Mini Solar Roll
The Mini Solar Roll stretches out to a full 18 inches when gathering solar energy. When it's time to break camp, it rolls up like sushi into a small pouch. The onboard lithium-ion battery is powerful enough to recharge your phone or camera when you need it, packing a lot of talk time into a very small package. Available late February 2013.
WEIGHT: 3.1 ounces
SIZE: 4.3 x 1.25 x 1.25 inches