When choosing a charging cable, most users focus on what they can see — nylon braiding, silicone coating, or overall thickness. However, the true performance of a cable is determined by what lies inside: the copper conductor.

The quality of the copper core directly affects three critical aspects:

Charging speed (voltage drop and current stability)

Heat generation and safety (energy loss and thermal control)

Service life (flexibility, fatigue resistance, and breakage risk)

Low-quality conductors are the root cause of slow charging, overheating, and early cable failure. In this article, we break down the industry reality and provide practical, technically sound methods to identify inferior copper cores — helping you protect charging safety, product reputation, and long-term business value.

1. Material Determines Everything: Comparing Three Common Conductor Types

Not all "copper" cables are created equal. In the charging cable industry, three conductor materials are most commonly used.

Tinned Copper (Tin-Plated Copper)

Tinned copper consists of pure copper strands coated with a thin layer of tin.

Advantages:

• Excellent corrosion and oxidation resistance

• Stable electrical performance over time

• Widely used in high-quality data and charging cables

Limitations:

• Slightly higher cost than bare copper

• Tin layer thickness must be well controlled

Typical use:

• Mid- to high-end charging and data cables

Oxygen-Free Copper (OFC / Pure Copper)

Oxygen-free copper is refined copper with extremely low oxygen content, offering very high conductivity.

Advantages:

• Conductivity close to theoretical maximum (~100% IACS)

• Lower resistance, minimal voltage drop

• Better heat control under high current

Limitations:

• Higher raw material cost

• Requires stricter manufacturing standards

Typical use:

lHigh-power fast charging cables (PD, PPS, USB-C to C)

Copper-Clad Aluminum (CCA)

CCA uses an aluminum core with a thin copper coating.

Advantages:

• Very low material cost

• Lightweight

Critical drawbacks:

• Conductivity only ~60% of pure copper

• High resistance → severe voltage drop

• Poor heat dissipation and fatigue resistance

• High risk of breakage and overheating

Typical use:

• Low-cost cables with short lifespan

Industry reality:

• Many ultra-cheap cables labeled as "copper" are actually CCA.

2. Understanding Wire Gauge: What Does a "Good AWG" Really Mean?

AWG (American Wire Gauge) defines the diameter of the conductor.

Important rule: Lower AWG number = thicker wire = lower resistance.

Why AWG Matters in Charging Cables

• Thicker copper reduces resistance

• Lower resistance minimizes voltage drop

• Stable voltage enables devices to maintain fast-charging protocols

Practical Reference for Fast Charging

Key insight: A cable claiming "100W fast charging" but using thin conductors will throttle power due to excessive voltage loss.

Professional buyers should always verify actual conductor AWG, not just outer diameter.

3. Practical Identification Methods: Real-World Testing Techniques

The following methods are widely used by engineers, QC teams, and experienced buyers. They are simple, repeatable, and technically valid.

3.1 Scratch Test (Surface Identification)

• Gently scrape the conductor with a blade

• Pure copper: uniform reddish color

• CCA: silver exterior with silvery aluminum core

This method quickly exposes copper-clad aluminum.

3.2 Burn Test (Material Verification)

• Carefully burn a small strand

• Pure copper: remains ductile, no powder residue

• CCA: aluminum core oxidizes, becomes brittle or powdery

This test should be performed in a controlled environment.

3.3 Flexibility and Fatigue Test

• Repeatedly bend the conductor at the same point

• High-purity copper: remains flexible, no cracking

• CCA: hardens quickly and breaks

Fatigue resistance is a strong indicator of long-term reliability.

3.4 Voltage Drop Test (Performance Validation)

• Measure voltage at cable input and output under load

• High-quality copper shows minimal voltage drop

• Inferior conductors exhibit significant loss under current

This is the most objective method for performance verification.

4. BWOO's Quality Philosophy: How We Define a "Good Copper Core"

At BWOO, conductor quality is not a marketing term — it is an engineering standard.

Strict Raw Material Selection

We only use refined copper with conductivity above 99%, rejecting recycled mixed copper and copper-clad aluminum. This ensures stable resistance and predictable electrical behavior.

Scientifically Designed Shielding Structure

Beyond thicker copper cores, BWOO cables integrate:

• Aluminum foil shielding

• High-density braided mesh

This structure reduces electromagnetic interference and ensures stable data transmission alongside high-power charging.

Extreme Load and Aging Tests

In our internal laboratory, cables undergo:

• 24-hour high-current load cycling

• Continuous power stress at rated capacity

The goal is to confirm that the copper core does not carbonize, fracture, or degrade under sustained high power.

5. Conclusion:

For buyers and brands, focusing solely on price often leads to higher return rates, safety complaints, and long-term brand damage — all rooted in poor conductor quality.

Choosing a supplier with transparent material standards and complete testing capabilities, such as BWOO, means you are not just buying a charging cable — you are investing in product reliability, customer trust, and after-sales peace of mind.