Bests & Worsts Reviews from Amazon

The panel is nicely made (though the USB port cover is fragile), but it is a 5W panel not 10W as advertised, hence the other negative reviews and my low rating. A normal charge these days is at least 1000mA. I was not able to get more than 440mA in direct sun. It works, it's just not a 10W panel and will typically give you a very slow charge. Why does this matter? A standard 1000mA charge @ 5V is 5W. If a panel is rated 5W then it needs perfect weather/time/position to achieve this. A 10W panel could much more easily supply the 5W output you are looking for under less than ideal conditions. This is not a 10W panel ...so probably not what you're looking for if you want a decent charge. For those who care, I believe these are higher than average output cells (Sunpower?) in the 22% efficiency range (no front tabbing wires or visible silicon structure). 10 series cells should yield close to 6V which is regulated down to 5V. The individual cell size is only 19mmx125mm, though, so at 0.00022mW/mm^2 (22% efficient cell, 1 Sun irradiance), ~520mW max per cell. 10x that for the 10 cells and the max output is about 5.2W. Encapsulation and buck regulator losses taken off of that ...and you're very lucky to come away with 5W output (1000mA @ 5V) even in maximum sun. The description says 1200mA USB output which is not possible, unless, as another reviewer mentioned, you were on the surface of the sun :-) If this was helpful please click below ...thanks!