This is a 18650 Li-ion holder for flashlights - designed specifically for mountain biking.
I used RTV silicone between the parts to make the case waterproof.
Each case contains 2x16850 cells(Panasonic NCR 3200mAh),1 PCB for 1p2s(8.4V), Waterproof DC connector and Velcro strip.
Panasonic NCR
http://www.gearbest.com/batteries/pp_189830.html?wid=21
18650_Frame_holder.STL | 10.7MB | |
18650_Helmet_holder.STL | 11.2MB | |
Cap.STL | 13.2MB |