USB Charging Box

This charges batteries as well as your device. I use it to connect to some solar panels so I can charge my batteries and device at the same time. I glued the top on to the case once everything was situated.

Box for charging devices
For the switch:
https://www.amazon.com/gp/product/B01N2U8PK0/ref=oh_aui_detailpage_o08_s01?ie=UTF8&psc=1

To charge your device, supports iPhones:
https://www.amazon.com/gp/product/B07F266X24/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

Battery Connection:
https://www.amazon.com/Micro-USB-Battery-Charger-Over-Discharge/dp/B01LHD9D7E/ref=sr_1_9?ie=UTF8&qid=1539641086&sr=8-9&keywords=micro+usb+converter+5v+step+up

18650 lithium batteries x2:
https://www.banggood.com/4PCS-MECO-3_7v-4000mAh-Protected-Rechargeable-18650-Li-ion-Battery-p-992723.html?rmmds=search