USB-C Charger Cable: Wattage Is the Spec
Quick answer / TL;DR: Short answer: match the cable wattage to the charger and device, and expect an e-marker above 3 A. Standard cables handle 60 W, marked cables 100 W, and EPR cables up to 240 W. Charging cables may carry no data at all, so buy separately if you also need transfer. Thicker, shorter cables run cooler at high wattage.
A patch cord is a stranded assembly: moulded boot, eight contacts, T568B.A charging cable only has to carry current safely and declare what it can carry. Above 3 A it must contain an e-marker chip.
That chip is the difference between a 100 W cable and a 60 W cable that looks the same.
Wattage Tiers
| Tier | Current | Power |
|---|
| Basic | 3 A | 60 W |
| Marked | 5 A | 100 W |
| EPR | 5 A at higher voltage | 240 W |
| Data | Varies | Separate rating |
The last row matters in practice: many bundled charging cables are charge-only and will not connect a drive.
Choosing
- Match wattage to charger
- Check for e-marker above 60 W
- Shorter runs cooler
- Avoid unbranded 100 W cables
- Keep data cables separate
An unmarked cable offered as 100 W is the specific risk to avoid; the device may refuse to negotiate or the plug may heat.
Real-World Applications
A laptop at 100 W needs a marked 5 A cable. A phone at 25 W is served by any compliant cable. A tablet at 45 W sits between the tiers.
Standards and Verification
| Reference | Relevance |
|---|
| USB PD | Power rules and EPR |
| USB Type-C | E-marker requirement |
| IEC 62368-1 | Safety |
Cable wattage for a specific product is not provided in the knowledge base. Check the marking.
References
- USB Power Delivery specification
- USB Type-C Cable and Connector Specification
- IEC 62368-1, Safety of IT equipment
Practical Notes
Tag the 100 W cables. They are the ones that matter and the ones most often swapped by mistake.
Related reading: usb c cable — blogs/news/usb-c-cable
Related reading: usb cable — blogs/news/usb-cable
Related reading: usb c to usb c cable — blogs/news/usb-c-to-usb-c-cable
Frequently Asked Questions
Do all C cables carry 100 W?
No. Above 60 W needs marking.
What is EPR?
Extended power range to 240 W.
Can it transfer data?
Some cannot at all.
Does length matter?
Yes, for heat and loss.
Sourcing cables for a project, a store, or a private-label line? Contact our B2B sales team for specifications, certification evidence, and volume terms – FOB and CIF options available. Request a quote or sample.
