The resistor is the cable’s rating label written in electrical form. A Type 2 plug carries a coding resistor that declares the maximum current that cable is built for, read by the car through the proximity pilot circuit when you plug in. Two cables built to different ratings carry different coding — a different resistor in your second cable usually just means the two cables belong to different current classes, not that one is faulty.
Key Takeaways
- The resistor in a Type 2 plug is coding: it declares the cable’s rated current class.
- Different class, different build — different coding.
- Never modify a plug: the coding only protects you while it honestly matches the conductors behind it.
What the Coding Resistor Actually Does
A loose charging cable has no screen and no electronics of its own, yet the equipment still needs to know what it can safely carry. The coding resistor is how a passive cable answers. When the connector seats, the car reads the coding and treats the declared class as a ceiling: even if the post could offer more, the session is capped at what the cable declares. The coding sits in the plug itself, fitted when the assembly is made — it is part of the cable, not an accessory.
As our comparison of Type 2 vs J1772 vs NACS connectors sets out, Type 2 builds cable identification into the plug, so a driver-supplied lead can be trusted by any post it meets. The equipment is not guessing from the cable’s thickness — it is reading a declaration.
Why Your Two Cables Carry Different Coding
Coding follows the build: if the build facts differ, the coding differs with them:
| What differs between the cables | What the coding declares |
|---|---|
| A 16 A cable next to a 32 A cable | Each plug declares its own current class |
| A single-phase version next to a three-phase version | The coding matches the build it was assembled with |
| A portable charger’s fixed lead next to a loose public-charging lead | The fixed lead’s coding is set for its unit; the loose lead declares its own class to any post |
| A plug replaced during a repair | Whatever the replacement plug carries — this is the case to check, below |
Two cables of the same class and build carry the same coding. A difference is the system working as designed: the plug is reporting a build difference.
When a Different Resistor Is a Warning Sign
The coding is only trustworthy if it matches the cable it sits in. Treat the difference as a warning — and stop using the cable at high current until the maker clarifies — when:
- The behaviour contradicts the printing. Sessions cap below the class printed on the jacket — coding declaring less than the printing claims.
- The plug is not the original. A re-terminated cable carries whatever coding the replacement plug brought with it, which may not match the conductors behind it.
- The cable has no traceable maker. On an unbranded lead, printing and coding can disagree with each other and with the build — one reason not all EV charging cables are the same, and why a cable that runs hot, covered in our guide to whether EV charging cables get hot, deserves suspicion.
Never open a plug or swap components to “correct” the coding. A declaration that overstates the conductors removes the protection the coding exists to provide. Diagnosing a suspect cable belongs with its maker.
Cables Matched at the Factory
The coding question disappears when the lead is part of a listed unit. The EVDANCE EV-ACS3210E is a 32 A Type 2 portable charger whose lead is built and coded for the unit’s single-phase design of about 7 kW. With a wallbox such as the EVDANCE EV-ACT3204E, offered with a Type 2 cable or a socket, the socket version is where your own cable’s coding joins the chain.
Frequently Asked Questions
Can I change the resistor to turn a 16 A cable into a 32 A cable?
No. The coding must match conductors and insulation built for the higher class. Changing the declaration without the build makes the cable misreport itself to the equipment. Never modify a charging plug.
Does the resistor itself set my charging speed?
It declares a ceiling, and the equipment honours it. If charger and car could both do more, the session sits at the cable’s class; if they offer less, the coding never comes into play.
Both my cables are marked 32 A, but the resistors differ. Is one wrong?
Possibly — markings and coding should agree, though a phase-variant difference can also sit behind it. Compare the full printed ratings; if the behaviour differs too, treat the cable as mis-declared until its maker confirms what it is.
Related Reading
- Which EV Charging Cable Do I Need?
- Are All EV Charging Cables the Same?
- Type 2 vs J1772 vs NACS: Which Connector Does Your Market Need?
- Do EV Charging Cables Get Hot?
