DIY Battery Spot Welding Pen – Copper Core 3mm Handheld Kit
DIY Battery Spot Welding Pen – Copper Core 3mm Handheld Kit
DIY Battery Spot Welding Pen – Handheld Copper Core Kit
Take your battery pack building and DIY spot welding projects to the next level with this precision-crafted handheld spot welding pen. Featuring a pure red copper body and a 3mm copper core, this pen delivers superior electrical conductivity — up to 3–5× greater than brass — while keeping heat generation minimal even under high current. Whether you're assembling 18650 battery packs or tackling custom electronics builds, this kit is built for reliable, consistent welds every time.
Key Features
- Pure Red Copper Construction: Outperforms brass with 3–5× higher electrical conductivity and significantly lower heat build-up under high current loads.
- Thread-Fixed Welding Tip: Threaded tip design ensures a firm, stable lock on the copper core needle — no slipping during use.
- Hydraulically Tightened Joints: All cable connections are hydraulically tightened for maximum contact surface area, delivering safe, reliable performance under heavy current flow — superior to screw-fixed designs.
- Compatible with 4AWG Cable (max ~7.5mm): Copper tube inner diameter of 8mm accommodates up to 4AWG cable for a snug, secure fit.
- Versatile Needle Length: Accepts a 100mm full-length welding needle, which can be cut into two sections for flexible use. Note: needles are manually processed; expect approx. ±8mm length variance and ±0.1mm diameter variance (core ~2.3–2.4mm).
- DIY-Friendly Design: Straightforward installation — unravel cable strands, twist tightly, and feed slowly into the copper tube (reserve 10–15mm inside for optimal contact).
- Hydraulic Pliers Recommended: For best results and full cable-to-pen-body contact, use hydraulic crimping pliers when tightening. This ensures a strong, low-resistance connection.
Specifications
- Core Material: Red Copper
- Core Diameter: Approx. 2.3–2.4mm
- Copper Tube Inner Diameter: 8mm
- Max Cable Gauge: 4AWG (~7.5mm)
- Welding Needle Length: 100mm (can be cut to 2 sections)
- Tip Fixing: Threaded tightening
- Package: 1 Set
- Made in Mainland China
What's in the Box?
- 1× Handheld Spot Welding Pen Set (copper body + welding needle)
Installation Tips
- Strip the cable end and unravel the wire strands.
- Twist strands tightly into a single stream.
- Slowly feed into the copper tube, leaving 10–15mm seated inside.
- Use hydraulic pliers to compress and lock the cable firmly into the pen body.
- Thread-tighten the welding needle tip to secure it in place.
Looking for more DIY tools and workshop accessories? Check out our Air Compressor Pressure Gauge – DIY Tool or our Electromagnetic Induction Tester – Coil & Circuit Fault Detector to complete your toolkit.
Note: Due to manual measurement, please allow ±1–3mm dimensional variance. Product color may vary slightly from images depending on monitor settings.
Learn more: OSHA on personal protective equipment
Frequently Asked Questions
Q: What type of copper is used in this spot welding pen, and why does it matter?
A: This spot welding pen is made from pure red copper — not brass. Red copper has an electrical conductivity rate 3–5 times higher than brass, meaning it passes current far more efficiently with much less heat build-up. This makes it ideal for DIY battery spot welding applications where consistent, high-current performance is critical.
Q: What is the maximum cable size I can use with this welding pen?
A: The copper tube has an inner diameter of 8mm and is compatible with cables up to 4AWG (approximately 7.5mm in diameter). To insert the cable, unravel the strands, twist them tightly, and slowly feed them into the tube, leaving 10–15mm of cable seated inside for a secure connection.
Q: Do I need any special tools to assemble this welding pen?
A: While the pen can be assembled by hand, it is strongly recommended to use hydraulic crimping pliers to tighten the cable into the pen body. Hydraulic tightening ensures full, firm contact between the cable and pen body, which is essential for safe and effective spot welding under high current — far superior to screw-based fixing methods.
Q: Can the welding needle be cut down to size?
A: Yes. The spot welding pen accommodates a 100mm full-length welding needle. You can cut one needle into two sections for use, giving you two tips from a single needle. The tip is secured via a threaded tightening mechanism for a firm, slip-free hold during welding.