Lots of people in the comments showed their own home-built soldering irons, so the creator upgrades his earlier DIY soldering station: materials are 6 Li-ion cells, 1 BMS, and a self-designed 3D-printed shell (came out well). Battery welding: fish paper on the positive ends for insulation, cells positioned to match the BMS wiring; welded with the AWithZ supercapacitor spot welder at gear 10, the pen with the manual button is convenient; weld the cells, the BMS balance leads and the power leads in turn, then insulate the battery. Main unit assembly: on the rear panel the left switch controls the battery and the right switch the main board, external power and charging port on top, sleep connector below; fit the main board with four screws, secure the battery and wire it as required, mind the polarity; fit the rear panel and it’s done, the outside fits together seamlessly; plug in the handle and the sleep socket, switch on the battery and the main board, and solder a board to test. Comments: one viewer reports an AWithZ that ‘starved’ twice after sitting for half a year — the first time it revived after a day and night on charge, the second time it didn’t after 36 hours and went back to the factory; don’t buy the big-capacitor type if you rarely use it (creator: didn’t know that could happen); T12 mod enthusiasts; some find the accessories over-complicated, simplicity is best.