Make your battery pack using your own 18650s or laptop batteries.
There are built-in tabs so do you not need to do your own soldering like other DIY battery packs, just put in the 18650s and you're good to go.
Comes with a light, an LCD screen showing charge percent, a 1.0A USB-A port, and a 2.1A USB-A port. Charges from a micro-USB.
18650 Battery Pack