Gallery: Sun on the Run: 4 Portable Solar Chargers Tested
01solar-chargers
The Basics __Do these charge fast enough to be practical?__ Finally, yes. As recently as 2008, when our gadgets were tied to various proprietary cables, the batteries in solar chargers had to be tuned to dispense power at the lowest common denominator to ensure the flow of electricity wouldn't overwhelm low-voltage connections. Now, thanks to USB ubiquity, getting power from a portable solar charger is just as fast as plugging into the wall. __How long to juice up my phone?__ A portable panel coated with standard monocrystalline silicon needs about two hours of direct sunlight to fully charge a smartphone. Flexible coatings of copper, indium, gallium, and selenide (CIGS) are slightly less efficient in direct sun but work better under cloud cover and behind UV glass, both of which cripple crystalline panels. But in general, bet on two to three hours. __How much power can these hold?__ The batteries in most portable chargers have capacities of around 8.1 watt-hours—enough to charge two smartphones. But some have batteries in the 20-Wh range. After a day in the sun, one of those can fully charge an iPad, smartphone, and point-and-shoot camera and still have juice left over. Buying Advice Don't do this to save money. In the U.S., electricity from the grid costs about 10 cents per kilowatt-hour. A $150 solar charger with a meaty 20-Wh battery would take nearly 75,000 charge cycles to pay for itself. But if you spend enough time outdoors and away from wall sockets, going solar is a great way to make sure you've got backup juice. If you live in Arizona, a cheap crystalline unit will be fine. Seattle residents will want the more expensive CIGS panels. Buy the biggest battery-panel combo your wallet and backpack will allow.
02solar-joos-orange
__Solar Joos Orange__ No need to handle this one gingerly. The Orange survived a biblical downpour, a one-story defenestration onto concrete, and use as a speed bump. (OK, we accidentally ran it over with a motorcycle.) It was also the fastest charger in our test, capable of bringing a dead iPhone back to 100 percent after less than an hour of direct sunlight. The monocrystalline silicon nitride panel slowed significantly under cloud cover, but eight hours of decent light completely filled the 20-Wh battery, which holds more than enough juice to get through the night. __WIRED__ Collapsible stilts for optimal angling. Simple design. Tough enough to survive a trip to Mars. Hole for hanging or securing. __TIRED__ Weighs almost 2 pounds. Doesn't like variable light. $149, __[Solar Joos Orange](http://solarjoos.com/)__
03solio-bolt
__Solio Bolt__ When it comes to charging iDevices, the dual-panel Bolt lives up to its name; an Apple setting optimizes flow for 30-pin connectors and let us juice up an iPhone 4S in 30 minutes. But getting power into the Bolt is a different story. The best way to angle it is to stick something through a hole in the hinge that's too small for anything but pencils and twigs. And the curved back makes it almost impossible to prop it against anything. So the Bolt spends most of its time on its back. With constant angle adjustment, we got it to fill its tiny 7.4-Wh battery in nine hours. __WIRED__ Fits in a jacket pocket. Friendly price. __TIRED__ Impractical design. Battery can't keep up with tablets. No automatic power-off means unintentional drain. $70, __[Solio Bolt](http://www.solio.com/chargers/solio-bolt/)__
04brunton-solaris-4-usb
__Brunton Solaris 4 USB__ Though just 8 ounces and an inch thick when closed, the Solaris' four flexible CIGS panels unfold into a 25- by 9-inch light-gathering array that can be draped over a tent, staked to the ground, or hung from a tree branch. Unfortunately, it doesn't come with a battery. You can charge directly from the USB port during daylight hours (slow) or fork over an extra $120 for Brunton's moderate 8.1-Wh battery unit—ours fully charged in less than four hours, but with all this square footage, we would prefer a higher-capacity option. __WIRED__ Outstanding surface- to-weight ratio. Flexible panels are easy to pack and use. __TIRED__ No battery included! CIGS panels, while versatile, drive up the price; even sans battery, this was our most expensive unit. $252, __[Brunton Solaris 4 USB](http://store.bruntonoutdoor.com/portable-power/panels-and-chargers/solaris-reg-4-usb/)__
05goal-zero-guide-10-mobile-plus-kit
__Goal Zero Guide 10 Mobile Plus Kit__ Goal Zero gets marks for flexibility. The paperback-sized unit's battery pack comprises four rechargeable AAs, equivalent to 10-Wh of storage. Plug in via USB to charge your mobile devices, or pull the batteries out to power non-rechargable gadgets like flashlights and cameras. Unfortunately, the tiny 3.5-inch panels that make this kit so packable required two days to deliver a full charge. And the Guide 10 has none of the Joos's design elegance. The Velcro closure is downright ugly, and the soft nylon case doesn't inspire much confidence. __WIRED__ Removable batteries. Power pack doubles as an emergency LED flashlight. __TIRED__ No legs for angling panels toward sun. Slow to charge. Not rugged enough for rough outdoor use. $129, __[Goal Zero Guide 10 Mobile Plus Kit](http://www.goalzero.com/shop/p/132/Guide-10-Plus-Mobile-Kit/1:1/)__
