Why Do Charging Cables Get Hot? [Answered]

USB cables are a part of every household nowadays. They are used to charge our devices and also to transfer data between them.

But sometimes, USB cables can get hot and this scares people into thinking that the cable might damage their phone or some other device. Don’t worry, in most cases, USB cables getting warm is perfectly normal.

Chargers convert the original voltage that comes from the wall socket. Since most smartphones require 5 volts while the wall power voltage may be between 100 and 120 volts so your charger converts it resulting in some heat.

In this blog post, we will explore why USB cables get hot and when you should be worried about it.

Why USB cable gets hot?

While we agree that it is perfectly fine for the charger to get heated up when in use in perfectly normal but excessive heat is not good. Look at a few of the causes of excessive heat in a charger below

The charging cable is old

Charging cables are not made to last forever. With time, the insulation on the wires breaks down and the cable gets damaged. This damaged cable is not able to transfer the current efficiently and gets heated up.

This happened to me recently I found an old Samsung( Good brand) cable. So I decided to use it as a secondary cable when I am outside.

In short, it got heated up to the point unable to touch or if I did not have unplugged it in time, the heat would damage my phone and might even cause a fire.

Cheap/ Bad quality cable

This is pretty self-explanatory. Cheap/ bad quality cables are not made of good material and often have thinner wires. If the wires are too thin then a higher current will cause more friction and heat the cable.

Mostly because low-cost USB cables are unlikely to have been produced using high-quality materials or sufficient safety precautions.

Therefore, it is always a good idea to buy a cable from a reputable brand even if it costs you slightly more.

Adapter is bad

This can be also the reason for your USB cable getting excessively hot. A bad adapter will not be able to convert the voltage properly and this might lead to too much heat being generated.

It’s best to use the right adapter for your particular phone or device. No matter how much money you spend on a good USB cable, if you are going to plug it into a bad adapter it will probably overheat.

It is always best to use the adapter that comes with your phone or buy a new one from the same company.

Is it normal for a charging cable to get hot?

Most of the time, yes. It is normal for your USB cable to get slightly warm when you are charging your device. This happens because the voltage is being converted from the wall socket voltage to the voltage required by your device.

Even while you can easily feel the heat emanating from your charger and it may make you uneasy, But as long as the temperature does not exceed 50 degrees Celsius (122 degrees Fahrenheit)

it is perfectly normal.

However, if you notice that your USB cable or charger is excessively hot to the point you are unable to touch it this can be a sign of danger and you should unplug it immediately.

Can a Hot USB Cable Cause Fire?

It is very unlikely that a USB cable will cause a fire. USB cables are designed to carry relatively low voltage and amperage compared to other types of electrical cables such as those used for your home’s electrical wiring.

However, even low current cables can cause a fire. The metal surrounding the cord can become electrically charged if it comes into contact with the prongs of a USB wall charger while charging, creating a risk of fire.

Putting your charging device on/in a poorly ventilated surface, such as a bed, under a pillow, on a couch, or in a location that receives direct sunlight, could also result in this problem.

Because the heat produced by the charger cannot be dissolved, it will continue to heat up over time and may eventually catch fire. Check out this article for more detail on this.

How do you stop your charger from getting hot?

If your charger is getting too hot, this means there is something wrong with it. The first thing you should do is unplug it from the wall socket and stop using it.

Place the gadget or charger on a flat table instead of a cushioned or ventilated surface for an immediate solution. To get the heat off the device, you might alternatively place it on a rack or platform where air can flow freely.


I hope you found this article helpful. In theory, it is perfectly fine to get the USB cable to get a bit warm when in use because of the voltage conversion.

However, if you notice that it is getting excessively hot to the point where it is uncomfortable to touch then there is something wrong and you should stop using it