It finally turns we found water on Mars (Finally! Since the time we talk about and that there are suspicions!) ! That is fine, but there is another planet, which is actually a star, just as interesting, and we are far from having been able to reap the benefits: the Sun! The Sun gives us light and we can convert this light energy through solar panels (it is far from a very high performance, but still there!). Here is the test of a solar battery charger panels: the Marsboy (I guess Sunboy is a company already used ^^ name) PETC-S14T 
Characteristics of the solar charger Marsboy 15 W
- Dual USB output. Meet the cost of two aircraft at the same time.
- Foldable compact size. Practice to use or transport.
- Waterproof and scratch-resistant.
- Model: PETC-S14T
- Material: PET, monocrystalline photovoltaic cell + PCB + film protector scratch-resistant matte
- Color: black
- Folded size: 19 x 25.5 x 2 cm
- Size unfolded: 80 x 25.5 x 2 cm
- Power: 15 W
- Output: 2 .1a / 2 .5A
The test of the PETC-S14T Marsboy
First thing to say is that these solar panels make their weight in peanuts: more than 500gr, almost 700. On a time T, it’s light enough, but in the long run, it might take more effort if you put it on your back hiking ;) At its size, by being folded back and comparison in order to see more clearly without measuring ruler, that does not exceed an A4 sheet in width and height, it is even smaller by about 2-3 cm. In unfolded, just imagine 4 A4 sheets glued next to the other. In short, very compact folded and pretty huge in being unf
o
lded! The surface of capture of the light rays is quite big, which allows to have an excellent outgoing intensity: theoretically, you’ll be able to have a 4.6 A total with 2 USB ports. I did not have to have 4, 6A, but this is quite normal because the conditions were not optimal: half clear sky (the Belgium is not a country known for its Sun, far from it!), but this charger depends on Sunshine! But despite the bad conditions, I even easily could all reach the 1.3 has which isn’t bad at all for of photovoltaic cells. About photovoltaic cells, therefore the monocrystalline silicon, pretty good performance. Very well protected and isolated from other 2 parties, waterproof and anti scratch. Unless it is done falling against a sharp object, it should withstand most small shocks. Although edges are compounds that seams, the fact that these edges are composed of solid plastic that also supports photovoltaic cells makes it all pretty solid. 
There is a Pocket, barely hinged with a small scratch in the Middle, which allows you to put your smartphone, mp3/mp4 player, gps, etc… so that it is reloaded quietly in his corner. The Pocket is not waterproof, unlike photovoltaic cells, but good, in case of rain, there is rarely much sun, and even if there is the Sun, your device to reload is probably not very waterproof. So I advise you to consider the whole thing as being permeable, as this will facilitate you the drying of the fabric strong enough passage, solar charger. 2 USB ports are surmounted by a circle which illuminates in blue when the charger senses a few rays of light. A port in white and one in white allow you to differentiate one 2.1 A (white) and 2.5 A (blue, which is reminiscent of the 3 USB ports). In the image we see pretty bad indicator lit in blue, but I was forced to put the flash otherwise we would not see the other details, but if you pay attention, you will see that the O is slightly blue and this is reflected on the other
side : The solar charger Marsboy does not natively battery.
Conclusion
Although having failed to reach maximum intensity due to weather conditions, this charger is still very powerful, and I have virtually no doubt that it can reach the 4A, especially at high altitude! Compact when folded, unfolded surface is fairly substantial. Photovoltaic cells are very well protected against scratches and small shocks. The fabric should easily support folding/deployment thousands of times in my opinion in the light of its strength. Presence of a flag that indicates when there is enough light to recharge something. 2 USB ports, which is 2.1 and the other at 2.5. Presence of a pouch that allows to place his device to reload. Link: in http://www.amazon.fr/gp/product/B0119L3816/ 