Battery tubes are components used in mods in order to house batteries and connect them easily. The contacts (both negative and positive) are connected to the top part of the tube via soldering.
Wires proportioned to the type of cell and to the amperage output of the device are highly recommended.
The soldering itself is very important to obtain optimal performance from this component: bad, poor quality soldering might affect the conductivity of the circuit. Where applicable, we also recommend to use heat shrinking sleeves to cover the solder area. The top cap can be disassembled to solder it more easily. Mind that it might take some time to heat the cap as it dissipates a lot being quite a big part made out of very conductive material.
The tube is made of stainless steel with black scratch proof coating. The battery cap threading is not coated in order to obtain the best performance, while the external surfaces are coated to obtain matching aesthetic. The battery pin is made of silver plated copper, while the top cap is made of silver plated brass with an array of holes for soldering the negative contact. The insulator is made of Ultem, a type of plastic with great mechanical properties, resistant to heat and chemicals.
Even if this won't affect basic functionality, we recommend you to insert the battery with the positive terminal facing the inner part of the tube (positive toward soldered wires). This way the battery body (which is part of the negative terminal) won't create any short-circuits in case of damaged battery wrapping, because orienting the battery like this the body of the tube will be connected to negative too.
This component can be held in place with an M3 grub screw. There is no need to glue it, just create a small pocket in front of the grub screw, then fasten the screw with an allen key from inside the tube. In order to machine the pocket we recommend a T-slot milling bit of appropriate size. Consider to make the pocket slightly smaller than the grub screw diameter. Using the grub screw is not mandatory, but strongly advised to avoid issues with tube fastening. You can see some pictures of the grub screw fastening process below.