Need advice on charging smartphone while /out/.

>yes I know I am a fag for taking my phone /out/

Leaning toward pic related.
https://www.amazon.com/gp/aw/d/B00NNFIT20/ref=mp_s_a_1_2?ie=UTF8&qid=1469637637&sr=8-2

I bought a piece of shit 2600mAh from walmart for $5. Wouldnt charge my phone past 30%. I use my phone for taking pictures/videos, gps, etc.
Since I do a lot of long distance hikes I would prefer something small and light that can charge a galaxy s6 2 or 3 times.
I have never tried portable solar panels. If you have experience with those any information would be appreciated.