Gold-Plated Bullet Banana Connectors – 2–8mm Pure Copper for RC Brushless Motor & ESC Wiring

Pure copper, gold-plated bullet (banana) connectors for RC brushless motor and ESC (Electronic Speed Controller) wiring. The bullet connector is the universal standard for RC motor phase connections — the cylindrical male bullet inserts into the female socket, providing a low-resistance, high-current connection that can be quickly disconnected for motor or ESC replacement. Gold plating on pure copper provides the lowest possible contact resistance — critical for high-current RC applications where connector resistance directly affects motor efficiency and heat generation.

Size Selection Guide

• 2mm: For micro and nano RC aircraft. Current capacity: ~10A. For motors below 100W.
• 3.5mm: The most common size for mini and small RC aircraft (250–450 class). Current capacity: ~30A. For motors 100–500W.
• 4mm: For medium RC aircraft and cars (450–550 class). Current capacity: ~40A. For motors 300–1000W.
• 5mm: For large RC aircraft and high-power cars. Current capacity: ~60A. For motors 500–2000W.
• 5.5mm: For high-power RC applications. Current capacity: ~70A.
• 6mm: For large RC aircraft, boats, and cars with high-current motors. Current capacity: ~80A.
• 8mm: For very high-power RC applications and electric vehicle motor connections. Current capacity: ~120A.

Key Specifications

• Material: Pure copper (C11000), gold-plated (24K, 0.5–1.0μm)
• Sizes Available: 2mm, 3.5mm, 4mm, 5mm, 5.5mm, 6mm, 8mm (select above)
• Termination: Solder type (hollow bullet for solder fill)
• Quantity: 40 pieces (20 male + 20 female)

Frequently Asked Questions

How do I solder bullet connectors?

1. Tin the wire end with solder. 2. Fill the hollow bullet connector cup with solder — heat the connector body (not the solder) until the solder flows freely into the cup. 3. Insert the tinned wire into the solder-filled cup while the solder is still liquid. 4. Hold still for 10–15 seconds until the solder solidifies. 5. Apply heat-shrink tubing over the solder joint. Key points: use a high-wattage iron (60–80W) — the copper bullet is a large heat sink and a low-wattage iron will not heat it sufficiently. Use 60/40 or 63/37 solder for best flow. Do not move the wire while the solder is solidifying — movement creates a cold joint.

What is the difference between 3.5mm and 4mm bullet connectors?

3.5mm bullets are rated for approximately 30A continuous; 4mm bullets for approximately 40A continuous. For RC aircraft, 3.5mm is standard for 3S–4S LiPo systems with motors drawing up to 30A. 4mm is standard for 4S–6S systems with motors drawing 30–40A. When in doubt, use the larger size — a 4mm connector on a 3.5mm application adds negligible weight and provides headroom for future motor upgrades.

Why use pure copper instead of brass for bullet connectors?

Pure copper has approximately 3× lower electrical resistivity than brass (1.7 μΩ·cm vs 6–7 μΩ·cm). In high-current RC applications, lower connector resistance means less voltage drop across the connector, less heat generation, and more power delivered to the motor. For a motor drawing 50A, a 1mΩ connector resistance difference results in 2.5W of additional heat generation per connector pair — significant in a weight-sensitive RC application.

Do I need to insulate bullet connectors?

Yes. Bare bullet connectors on motor phase wires can short against each other or against the frame if they touch. Apply heat-shrink tubing over each connector after soldering — leave only the mating end exposed. For battery connections (positive and negative), use different-colored heat-shrink (red for positive, black for negative) to prevent polarity reversal.

Typical Applications

• RC aircraft: Brushless motor phase connections (3-phase: 3 bullet connectors per motor-ESC pair)
• RC cars & trucks: Motor-to-ESC connections on brushless RC vehicles
• RC boats: Waterproof motor connections (with heat-shrink insulation)
• LiPo batteries: Battery-to-ESC power connections (with appropriate current rating)
• Electric vehicles: Low-voltage motor phase connections on small EVs and e-bikes

Package Contents

40 pieces — 20 male bullet connectors + 20 female bullet connectors (size as selected above).