EV charging cables use copper because it conducts electricity better than any other affordable metal, stays flexible when finely stranded and makes reliable connections at the pins. Aluminium is lighter and cheaper but conducts only about 61% as well, so it needs thicker conductors and special terminations. That is why aluminium appears in some fixed supply wiring, while flexible charging cables stay copper.
Key Takeaways
- Copper is the reference conductor; aluminium conducts about 61% as well.
- Flexible charging cables use copper for conductivity, flexibility and reliable pins.
- Aluminium can suit fixed supply wiring if sized and terminated per the NEC.
- Copper costs more because of scarcity, mining limits, demand and trade policy.
How Does Copper Transfer Electricity?
Each copper atom has one loosely held outer electron. In solid copper these electrons are free to move through the metal lattice. When a voltage is applied, they drift together in one direction, and that flow is the current. Every metal resists this drift a little, and the resistance turns some energy into heat (power loss = current² × resistance).
Copper’s resistance is very low, so less energy is lost as heat for a given conductor size. Electrical conductivity is even measured against copper: the International Annealed Copper Standard (IACS) defines annealed copper as 100%. Lower loss matters in charging because the current is high and continuous for hours, a point our article on whether EV charging cables get hot covers in detail.
Copper vs Aluminium for EV Charging
| Property | Copper | Aluminium |
|---|---|---|
| Conductivity (IACS) | 100% (reference) | About 61% |
| Density | 8.96 g/cm³ | 2.70 g/cm³ |
| Size for same current | Smaller | Larger (often one or two AWG sizes up) |
| Flexibility and fatigue | Good when finely stranded | Weaker under repeated bending |
| Terminations | Standard lugs and pins | Must use connectors rated for aluminium |
| Typical use in charging | Charging cables, internal wiring | Some feeders and supply circuits |
The ampacity tables in the National Electrical Code show the trade-off. In the common 75 °C column, 8 AWG copper and 6 AWG aluminium are both rated 50 A, and 6 AWG copper and 4 AWG aluminium are both rated 65 A. Aluminium can be legal and economical for long supply runs if the installer follows the code and the equipment terminals are listed for it. Our guide to wire size for EV chargers explains sizing, and a licensed electrician should make the final call.
Why Is Copper More Expensive Than Aluminium?
- Scarcity: aluminium is the most abundant metal in Earth’s crust; copper is far scarcer and found in lower concentrations.
- Ore grades and mining: the U.S. Geological Survey notes U.S. copper output in 2025 was affected by lower ore grades and concentrator shutdowns at several mines.
- Mass per job: copper is about 3.3 times denser, so a given length of conductor uses more metal by weight, even though it can be thinner.
- Demand from electrification: grids, buildings, electronics and EVs all compete for it.
- Trade policy: the USGS attributed record U.S. copper prices in 2025 mainly to uncertainty about tariffs on copper imports.
The USGS also lists aluminium as a substitute for copper in power cable and electrical equipment, which is exactly the fixed-wiring trade-off above.
What This Means for Charger Buyers
A cheaper charger sometimes hides thinner or copper-clad aluminium conductors. Ask for the conductor material, size and cable standard, and check certification. Our article on whether all EV charging cables are the same lists what to compare. EVDANCE uses copper conductors in its charging cables, including on the EV-ACT5006T 48A Level 2 wall charger, and can provide cable specifications for OEM orders.
Frequently Asked Questions
Why is copper so expensive?
It is scarcer than aluminium, harder to mine as ore grades fall, and in high demand for electrification. Tariff uncertainty pushed U.S. prices higher in 2025, according to the USGS.
Can aluminium wire be used for an EV charger circuit?
In some cases, yes, if it is sized per the NEC and the terminals are rated for aluminium. Ask a licensed electrician.
Is copper-clad aluminium safe for EV charging cables?
Treat it with caution. It conducts less well than solid copper of the same size. Choose certified cables with documented copper conductors.
Related Reading
- How Is an EV Charger Wired? A Plain-English Overview
- What Size Breaker Do I Need for an EV Charger?
- How Long Do EV Charging Cables Last?
- How to Read an EV Charger Datasheet
