I built a straight 3.7 lipo mod with a fasttech case, cut length down a bit for size, https://www.fasttech.com/products/1379500, put a lipo battery in it Turnigy 1000mAh 1S 20C Lipoly, and a USB charger out the bottom https://www.fasttech.com/products/1453504 It has a simple radio shack fire...