Bilingual Chinese / English captions. Followers want to DIY FPV drone packs with a good discharge rate and long flight time, so first the prep: the pack body is 21700 or 18650 — the former has a higher discharge rate and more capacity but is bigger, choose to suit; fish paper; balance leads (pick a balance connector for however many S you need); power leads; copper and nickel strip; heat-shrink tubing for the outer protection. Tools: scissors, a soldering iron, and most important the spot welder — this AWithZ compact spot welder UF20B, which reaches welding condition in about 1 minute, much faster than the 20-plus minutes of other welders on the market; high power, up to 10.5kW, up to 1750A output; officially rated to weld 0.4mm nickel-plated steel strip, easily enough for drone packs; the welding pen has two modes: auto (press and it fires) and manual (pen trigger); preheat time selectable 1–10ms, 1 or 2 pulses selectable; screen reads 29°C. Assembly next episode. Comments: ‘it’s your fault, I bought the same one’; 18650s blow up easily, pouch cells are safer (creator replied); can pouch cells be used (creator: yes); only use it a few times a year so bought a P60F; does the welder go bang.