It states 20000mah lipo battery. I wish you opened it.. It can only manage to charge once my ohone with 4800mah battery.. ONCE and that's it. Literally no juice left after one full charge on my phone from 10% bat left
I think if you left it outside all day it may charge but really I keep it hanging in my kitchen and just the lights in their keep this thing charged all the time.
for the first use you're supposed to use the USB. after that it should capture sunlight better. this is with all chargers I've read about too, so not exclusive. try it and see.