Have you ever plugged a fast-charging compatible device, like a smartphone, into a USB-C cable that only charges slowly? It happens to the best of us. That’s because while the USB Type-C standard ensures that most connectors are similar, it doesn’t necessarily standardize the technology inside the cable. Not all USB-C cables are created equal. If you’re wondering why the USB-C standard is so important – and it’s a valid question – it’s because it makes peripheral ports and connectors on cables and accessories fundamentally more versatile.
You should always be aware of the power output of a cable. USB-C is actually divided into several variants, where standardization exists for the connector. It starts with USB-C 2.0, the entry-level version, capable of data transfer rates of up to 480 Mbps. From there, you have USB 3.2 Gen 1, Gen 2, Gen 2×2, and USB 4, which supports PD (Power Delivery) and Thunderbolt. USB-C PD supports fast charging with power up to 100 watts in some cables and with a maximum of 240 watts in newer cables.
Because this can be confusing, the best explanation is that each version of USB-C is capable of providing different output powers. You need at least 18 watts or more to facilitate fast charging. Ideally, for modern devices, you need a 40-65 watt charger and cable, depending on the electrical needs of the device. If you use a cable that is not rated for higher power output, no matter what the power adapter provides, your devices will not be able to charge quickly. The cable limits the amount of energy supplied. Additionally, there are specialized cables for data, video, audio, and power compared to other options.
What changes the charging performance of a USB Type-C cable?
The connector for USB Type-C is the standardized part you’ll recognize that makes it easy to connect modern charging cables and data cables between compatible devices. It is reversible and shares the same design across all platforms. But it’s what’s inside the cable that truly influences the power capabilities of the entire connection.
The cable “gauge” or thickness of the wires inside determines the data or power limits. A lower gauge number means a thicker design while a higher gauge number means thinner. Higher gauges can interfere with efficient power delivery, resulting in less power flow and slower charge times. Cable length can also change cable performance. Longer cables have to deal with more resistance, which means more power or voltage loss and lower charging rates.
The final piece of the puzzle is general compatibility. For example, PD or Power Delivery standard is necessary for high output power. If the cable in question doesn’t support PD over USB-C, you won’t be able to get the high power needed for fast charging. Additionally, because some cables are specialized, if you opt for a data cable rather than one that prioritizes power delivery, you might see slower charging speeds.
How do you know which USB-C cable is the right one to use?
USB-C cables are made in different ways – that’s exactly why they’re not all the same. The easiest way to identify a cable’s specifications is to read and follow the manufacturer’s product information, whether on the brand’s website or retailer listing. This is not always available, in which case you can look for a certification logo from the USB Implementers Forum (USB-IF). It must appear on the original cable packaging and sometimes, very rarely, on the cable itself. Certified cables have passed the necessary tests to guarantee their high performance.
You can also consider features like the thickness and feel of the cable, whether it is braided or made from premium materials, and whether or not the e-marker chip is present in high-power cables. This chip, which stands for Electronically Marked, exists in cables rated 60 watts and above and acts as a safety controller preventing more power from flowing than the cable can handle. If the chip is not present and the cable advertises 60 watts or more, this presents a safety risk.
Ultimately, if you have trouble finding information about the cable’s PD support or specifications, if you can’t identify any USB-IF logos on the packaging, or if it looks cheap, you’ll want to avoid it. There is a lot of confusion around USB-C, beyond cables. If your device isn’t charging quickly, it may not be because of the cable. For example, a common myth about USB-C ports is that the ports themselves are all the same, but they’re not. Some ports may support high power and fast charging, while others do not.