Building a camper Interior? Can’t afford a Zig charging Unit? Why not build your own!!! This guide will guide you through the process of building your own Zig charger unit from as little as £5 to £10. A self built zig unit will power everything you need in your van. They are safe, reliable and fused! In building a Zig Unit there is a small amount of soldering and you will need an electrical tester. Upon purchasing, you will be able to download the PDF file.