I have a 20,000 mAh Limefuel battery pack with two USB ports. (Amazon only sells a 15,000 mAh version now.) I charged my phone from it for several days to get it down to 10%. I wish I had counted how many charges I got from it. That would have been useful information.
|Limefuel 20,000 mAh USB battery pack.|
digital meter so I'd have some idea of what it was actually doing. My initial results were not good. It was cloudy so the panel only produced 0.5 watts.