My first thought when I picked up the JOOS Orange solar charger was holy cow this thing is heavy! The main unit weighs a solid pound and a half. Then I realized the JOOS is not just a charger, as the name might lead you to believe; it has a replaceable 5,400 mAh battery built in. That and the rest of the feature set changed everything.
The JOOS is heavy, even more so than taking a separate charger and equivalent external battery, but the JOOS has a number of features that really put it in its own niche. For starters, the JOOS Orange is damn efficient. They claim it charges 3.5x faster than equivalent panels, and while we can't verify that it definitely charges damn fast. I left it out to charge on a cloudy day when I left for work, and when I returned less than 8 hours later it had enough juice to fully charge an iPhone with a little left over. Did I mention it was cloudy? The JOOS doesn't seem to care, it will still charge, albeit more slowly. It will also charge from a USB port, e.g. from your plugged in computer, so it's ready to go adventuring the next morning.
Fully charged after a full day of sunlight (OK, it's an Alaskan summer day, so that's a bit longer...) the JOOS has enough juice for at least two full charges on an iPhone. And here's another bonus: the JOOS can charge while underwater. In fact the JOOS is NEMA 6P waterproof - yes, proof, not just resistant. This is useful in a number of scenarios, one being on a boat where could clip a small flotation device into the carabiner hole in case it falls overboard. Sweet!
Other features inlcude a charging indicator to tell you its harvesting photons, a battery charge indicator, multiple charging tips (iPad/iPhone and micro/mini/female USB) and last but not least the ability of the urethane-encapsulated monocrystalline solar cells to retain a charge, according to the manufacturer for years. This is no small thing, especially if you live in an area prone to manmade or natural disasters. You can charge the JOOS and leave it in your bug-out bag without worrying about whether it will be charged when you need it.
The JOOS is heavy but not overly large: about 7/8" thick,5.75" wide and 8 and 5/8" tall. A small rubber plug covers the bottom charging port, and two plastic legs pop out of the back to stand it up for proper orientation. Overall, the JOOS is a great choice if you're looking for a charge-it and forget-it device, a combined charger and battery with a fast charge time, and/or a charger/battery that can live on or near the water. Also available is a reflector kit for $24.95 that makes the JOOS even more efficient.