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Li-ion DIY safety guide

DIY lithium packs can catch fire: check cells for shorts before welding, always add a BMS, never skip insulation and fusing on high-current builds.

Before welding

  • Use matched, healthy cells; never mix old and new.
  • Work on an insulated surface; remove rings and watches.

While welding

  • Two points per tab, needles perpendicular, no dragging.
  • Stop if a cell heats up or a weld sparks excessively.

After

  • Always add a BMS; insulate positives with barley paper.
  • Charge the first cycle supervised.