This is the second one of these I’ve had now (the first one was stolen)… it charges it’s little internal battery using sunlight from the two solar panels and does a pretty damn good job of it too!
Minor flaws? – yes – the annoyance of having to use an adaptor system to charge the Ameo and various other things when a USB socket would have been easier… oh and be careful on hot days – it does get quite hot to touch if left in the sun! (duh!)
The design is fantastic and pocketable, and the fact you can keep it topped up from USB on your laptop is great too so the solar charging facility isn’t the only way of charging it… however I wouldn’t rely on the sun to charge it too quickly – you’re looking at a couple of days in bright sunlight to get anywhere near full.