The creator takes 54 × 5C-discharge 18650 cells (about 16mΩ internal resistance; IR and voltage tested first, any 20mΩ cells swapped out) and loads them into snap-together triple holders for a 3S18P pack, 12.6V full and 36000mAh; fish paper on the positive ends against shorts. Spot-welded with double-layer nickel strip on the high-power AWithZ welder; midway the two pens touched and blew through the strip and one cell, so that cell was pulled and replaced. A 120A balancing BMS goes on, the main + and − are brought out with copper wire wrapped around and flooded with solder from the iron, then wrapped in fish paper and fibre tape. The box gets a bidirectional smart meter (with shunt), a 220V socket, power switch, 90W USB fast-charge module, wireless charging module, a CC/CV buck-boost charging module with 5–30V input (output set to 12.6/12.8V, about 5A, diode in series), a 600W / 1200W-peak pure sine wave inverter, two fans + three 40℃ thermostat switches in parallel (one each on the inverter heatsink, the BMS and the buck-boost module), and finally a carry handle. It can cook rice and run a hot pot, drive power tools, jump-charge an e-bike, and charge straight from any 5–30V charger or solar panel.