HELP: USB Solar panel Charging for PSP 1000

[cobi_vw]

Hi, i need some help with the connection of the solar panel to the power source of the PSP

Would it be better to connect the solar panel internally, directly on the power source: Therefore building it into the back of my PSP (see image 3) 
OR

Connecting the USB input to the power source and modding the panel so that I can plug it in the USB port??


This is the solar panel im using: (image 1 and 2)