DIY high-power flashlight tutorial: three 18650 cells and an e-bike headlight for under ¥20

DIY flashlight — 3×18650 + e-bike LED, under ¥20

Unboxing and testing a small handheld spot welder — very practical and handy

Fixing a fan’s laptop battery that died in storage

Fixing a dead laptop battery for a follower

Spot-welding power-bank cells with the AWithZ portable welder. Spot-welding power-bank cells with the AWithZ portable welder. After long use a power bank's capacity drops. A shame to throw it away; swap in a few high-capacity cells and it works again

A neat trick for welding Li-ion cells

Trying the AWithZ small handheld spot welder — if you don’t weld much and want to do some DIY, worth considering

No flashlight repair today — replacing the 18650s inside a Milwaukee 12V battery

Repairing a Boda cordless drill: new Li-ion cells, spot-welded pack assembly. A friend was about to throw out a dead drill — both batteries dead, the drill dead too, only the charger worked. I fixed it, so I’m not giving it back, I’ll use it myself

Swapping a flashlight battery with a handheld mini Li-ion spot welder. The handheld mini welder is easy to carry and works for re-celling power banks, players and other small gadgets. Solder a Li-ion cell with an iron and the heat raises the pressure inside and can ruin the cell — only a spot welder will do