USB-C cable works for data but charges slowly

Your USB-C cable transfers files, but your phone, tablet or laptop charges much more slowly than expected. That can happen because data transfer and charging power use different capabilities, even when the cable and connectors look the same.

Compare charging rates with the Charger & Cable Test, then swap one part at a time. This helps you narrow down whether the cable, charger, device or charging conditions are limiting the speed.

Compare the cable and charger

1. Open the Charger & Cable Test on the battery-powered device you want to check. The test appears only when your browser reports battery information.
2. Connect the charger directly to a wall outlet and the device. Let the battery charge for a few minutes, then note the test's charging speed in percent per minute.
3. Keep the same device, charger, outlet and conditions, but replace only the USB-C cable. Wait a few minutes and note the new rate.
4. If you have another compatible charger, repeat the comparison with that charger while keeping the better-performing cable in place.
5. For a fair comparison, keep the screen off and avoid demanding tasks. Compare readings at similar battery levels, ideally below 80 percent, because charging often slows as the battery fills.

The test gives a comparison in percent per minute, not the cable's exact wattage. A short test can vary with battery level, temperature and device activity, so look for a clear difference rather than treating one reading as a precise rating.

What the result means

One cable charges noticeably slower

The cable is a likely limit, especially if the difference repeats with the same charger and device. It could have a lower power rating, worn contacts or internal damage. Data can still work because a successful file transfer does not prove the cable can carry high charging current reliably.

Both cables charge slowly with one charger

The charger, outlet, charging port or device may be the limit. A charger can provide less power than the device accepts, or a USB hub, dock or computer port may share or restrict its power. Try a suitable wall charger before blaming the cable.

Every combination charges slowly

Check the device's temperature, charging settings and port. Some devices reduce charging speed when hot, while battery protection features may pause or limit charging near a set level. If the device charges slowly with known-good compatible equipment while cool and idle, the device or its port may need service.

The rate changes from one test to the next

This is common when the battery level, temperature or workload changes. Repeat the comparison at similar charge levels with the screen off. The percent-per-minute figure is useful for comparing setups, but it cannot identify a cable's exact power rating or prove that a charger is electrically safe. See what charging tests cannot tell you about electrical safety.

How to fix slow USB-C charging

1. Connect directly to a wall charger. Bypass a dock, hub, monitor or computer port. These can provide less power than a wall adapter or share power with other connected devices.
2. Use a cable and charger rated for your device. Check the device maker's charging guidance and the ratings printed on the charger or cable packaging. USB-C describes the connector shape, not a guaranteed charging speed. USB Power Delivery, often shortened to USB PD, is a charging standard that lets compatible devices and chargers agree on a supported power level. Some cables need an electronic marker to support higher current. For more on connector limits, read why a USB-C connector does not guarantee high speed.
3. Try another port and inspect the connectors. Disconnect the cable and check for bent, loose or dirty contacts. Do not scrape inside a port with a metal object. If the plug feels loose or charging changes when you move it, stop using that cable or port until you can check it safely.
4. Let the device cool and reduce its workload. Remove a thick case if the device feels hot, keep it out of direct sun and close games or other demanding apps. A warm battery or active device may charge more slowly by design.
5. Check battery charging options. On Windows 11, open Settings › System › Power & battery and check any battery or charging controls provided by the computer maker. On macOS, open System Settings › Battery and review Battery Health and charging options. On iPhone, check Settings › Battery › Charging or Battery Health & Charging, depending on your iOS version. On Android, look under Settings › Battery for charging optimization or battery protection; menu names vary by manufacturer. These features can hold the battery below full or adjust charging to protect it, so check whether a limit is active.
6. Restart the device and test again. If charging remains slow after a restart with a known-good cable and compatible charger, the problem may be with the charging port, battery or device electronics.

When the cable or device needs replacement

If one cable repeatedly charges slowly while another works well in the same setup, replace the slow cable. Stop using a cable that is frayed, has a loose plug, becomes unusually hot or makes charging cut in and out. If several compatible cables and chargers all charge one device slowly, but work normally with another device, have the charging port and battery checked by the manufacturer or a repair shop.

Why file transfer does not prove fast charging

A USB-C cable contains separate connections for data and power. A data transfer shows that the data path works, but it does not show that the cable supports the same charging current as a newer, higher-rated cable. The charger and device also have to support a compatible charging level, and the device controls how much power it accepts.

That is why the most useful check is a controlled swap: keep the device and charger the same, change just the cable, and compare the charging rate under similar conditions.