Last week we went out to Dartmoor, camping with no electricity or running water. Just beforehand, my friend Jan posted that he'd just received his "Waka Waka" solar charger / light in the post. I think he funded their Kickstarter project - apparently the company started with a solar-powered LED light intended for developing countries, one of those business models where they use the profits from selling their neat little device in wealthy countries to support making it available in poorer countries.
Anyway, so Waka Waka make this neat-looking little solar charger that can provide reading light or can charge your phone via USB. Possibly ideal for camping trips, so I got one too. I don't have much experience with other solar cells but here's my review of this one. Looks neat doesn't it?
The short review: Really pleasant and functional design which can sit/stand/hang anywhere or fold away. In southern England in August, it needs a proper sunny day to charge my smartphone all the way up (i.e. it can't do a full charge every day) but it's great for topping up a phone so you can keep using it. The LED light is surprisingly bright and pleasantly-coloured.
Some extra notes:
I should mention that my main aim was to keep the smartphone charged up so I could use it for GPS and important phone calls. For that reason, we didn't use the LED light feature much (so that we didn't run it down), so I guess I can't really evaluate the LEDs beyond saying they're lovely and bright and neutrally-coloured, and apparently can last for dozens of hours from a single charge. So, having said that:
It has nicely-thought-out status lights so you know what's going on. A subtly flashing "bip-bip" indicates how fast it's charging, and a blue light lets you know when it's charging up your USB device.
In southern England (latitude about 50 degrees) in August, it needs a good sunny day to charge all the way from zero to full. With varied sunshine, it charges up pretty far, but only enough to get my smartphone up to about two-thirds. That's not a bad deal at all, and if you live in sunnier climes or if you use your smartphone moderately rather than running it dry each day, I guess you'll have no trouble at all. (Though in less-sunny climes, or if it's not summer....) Also, I didn't "optimise" the position of the solar panel too heavily, just left it on the roof of the tent, pointed it at the sun, and went out walking for the day.
Once charged, it doesn't hold its charge for ever. It seems that overnight it can fall back from its 4-bars full status down to 2-bars. So it's not exactly like you can treat it as a "spare battery" once charged, I'd guess it makes sense to use the charge within a day if you're going to.
Waterproofness: I must admit I'm a bit baffled by the instructions. Apparently it's rainproof on one side (the solar panel side) but not on the other side. So does this mean it's OK to leave it out in the rain, or not? Well, who knows - but I left it out all day, on at least a couple of days and nights when it rained pretty heavily, and it seems fine.
It looks like an iphone in a holder! Now you might think that's just irrelevant. Actually, we live in London so it means I can't leave it outside to charge, and can't really leave it prominently showing anywhere, in case it gets swiped. Luckily, on holiday we were in the middle of a field with no-one around.
As I said, the design of the thing is v pleasant - nice simple block design that has a robust feel to it, including the little stand bit that folds out. Also the stand has a hole that can be used for standing the thing on a bottle, or hanging it from the ceiling, or strapping it to your back-pack. Neat.