Guide:
https://learn.adafruit.com/usb-dc-and-solar-lipoly-charger
Hookup Diagram/Photo
https://cdn-learn.adafruit.com/assets/assets/000/034/573/original/projects_batt_load.jpg?1470259382
Solar Charger
https://www.adafruit.com/products/390
Solar Panel
https://www.adafruit.com/products/200
Barrel jack adapter
https://www.adafruit.com/products/2788
Part to attach the load
VERTER 5V USB Buck-Boost
https://www.adafruit.com/products/2190
A USB A Jack to 5.5/2.1mm barrel jack adapter comes in handy to use with a
long USB extension.
https://www.adafruit.com/product/988