Whether it's a 10-day trek through the Rocky Mountains or just an afternoon spent in Central Park, unplugging from the grid for a bit is the best way we know to recharge our inner batteries. Unfortunately, the batteries we've come to depend on even off the grid – for our GPS system, UV water purifier, digital camera, music player – just don't feel the same way. Recently we tested out the new Bushnell SolarWrap 400 panel and found it powerful enough for all our needs, while remaining sufficiently lightweight, low profile, and durable to be worth packing for any trip into the hinterlands.
Bushnell's SolarWrap series of solar panels are water-resistant and flexible, and roll up window shade-style into a lightweight, ruggedized canister-style carrying case (we tested the 400 model, which weighs just 10 ounces). Built into the case is a standard USB port (tucked behind a waterproof rubber stop) for charging most mobile devices, as well as a lithium-ion battery for storing a charge. So you aren't limited to trickle charging when the sun is shining, and can pre-charge the battery via a wall outlet before heading out.
Using the sun to fill up the internal battery takes about six hours in sunlight – it even registered a charge with cloud cover – and provides enough juice to completely recharge about five camera batteries, or two smartphones, or the equivalent. And unlike some models we've tested, that's it: no blinking LEDs to decipher or special situations to consider. [$180; bushnell.com]