Top 3 Ways to Charge a Laptop With USB

Laptops continue to be an indispensable part of our personal and professional lives. Regardless of your laptop’s configuration and features, the power supply remains a fundamental component that enables its smooth operation. But what happens if you don’t have access to the power supply?

Maybe you left your house in a hurry and forgot to pack your charger. It’s also possible that your charger gave up the ghost and simply stopped working. Sometimes efficient charging is also impossible because the charger’s connector is defective.

Regardless of why you can’t use a charger, the right USB cable can help you out. How to do it? Let’s find out!

How To Charge Laptop with Usb?

You can use modern cables like the USB-C cable to charge your laptop. However, it’s important to know that your laptop needs a USB-C port to charge devices. Also, not every laptop with a Type-C port may allow charging.

This means that with the right USB cable, you can charge your laptop even if you don’t have the standard charger. For some time now, USB cables have been used mainly for charging smaller devices such as smartphones or audio players.

So you’ll need to check your device’s manual or the manufacturer’s instructions to see if it works for you. If it works with your laptop, all you need is a suitable USB-C cable and a power source to charge your laptop.

How to Charge a Laptop With USB-C?

The safest way to charge your laptop with a USB-C cable is if your device comes with one. Laptops with USB-C chargers usually have an adapter/power brick and a plug on one end and a Type-C connecting cable on the other.

It should be noted that not all USB-C ports are meant for charging. While they’re all suitable for data transfer, only certain Type-C ports can charge your device. Check your laptop’s user manual to see if your port supports charging. For example, if your laptop is an ASUS notebook, there are several icons that indicate what the different ports can do.

If your laptop has both slots for a traditional charger and a USB-C charging port, the first port is usually more efficient. However, the USB-C port is a convenient alternative if you don’t have your standard charger with you.

Depending on the make and model of your laptop, you can experience different charging speeds. Both the laptop’s power delivery mechanism and the choice of cable determine the charging speed. For example, a basic Chromebook will charge at about 40W, while a high-end MacBook can charge at over 80W.

Can You Charge a Laptop With a USB?

Yes. With the right cable and connector, you can charge your laptop with a handy USB cable. The 2013 update of USB 3.0 increased the power to 100W, creating the new USB 3.1.

With subsequent improvements to USB technology, it’s not that difficult to charge your laptop via USB today. Of course, your laptop needs to be equipped with a USB Type-C charging port, and you’ll also need a power source. But aside from that, it’s possible to provide your laptop with much-needed power even if you don’t have a traditional charger nearby.

Also, you can choose between different power sources depending on the situation. Whether it’s an extra powerbank or your car’s charging port, there’s more than one alternative to charge your laptop when using a USB cable. The most important thing is to know your laptop’s ports and choose the right cable.

We’ve created an easy-to-follow guide that shows you how to charge your laptop with the right USB cable.

USB Power Explained

Before we get into the specific instructions, let’s first understand how USB power works. Traditionally, USB cables have been used for data transfer, not power. The focus on data transfer efficiency becomes clear when you look at the improvement in transfer speeds over the years.

Version name Speed Released Rate of transmission
USB 1.1 Full Speed 1998 12 Mbps
USB 2.0 High Speed 2000 480 Mbps
USB 3.0 SuperSpeed U 2008 5 Gbps
USB 3.1 SuperSpeed+ 2013 10 Gbps
Source: CMD’s Table on different versions of USB

With a few updates, however, USB cables developed the secondary role of providing power as well as data. Although the initial power was low, developments in USB technology over the last decade have changed this scenario. USB cables can’t only charge phones and power mice, but also charge monitors and laptops.

In 2010, the Battery Charging Specification – BC 1.2 raised USB power transfer from a measly 4.5W to a respectable 7.5W. This new transmission is also called CDP (Charging Downstream Port) and delivers a higher current of 1.5 A for charging devices.

After further updates, the USB cable now offers higher power output and improved data transmission. Therefore, it can charge larger devices that were previously too heavy for USB cables.

How To Charge Your Laptop in a Car

Your car’s alternator powers all of your car’s electrical components. So a power source that powers your music system or illuminates your headlights can also charge your laptop.

Of course, you’ll need to take a few precautions first, since your car isn’t originally designed to charge laptops. The simplest solution consists of a AC adapter and a car charger with a USB port. The AC adapter should have a conventional USB-A port on one side and a USB-C cable on the other. Many modern cars now have built-in USB ports in the dashboard. So the USB charger may not be needed at all.

With these ports ready, charging your laptop is as easy as plugging it in.

  • Step 1: Turn on the ignition to get the engine running. With the right voltage, you may be able to charge the device by merely turning on your car’s battery/accessory mode. But a running engine is the safest bet.
  • Step 2: Plug the USB charger into the car’s charging/lighter port. The Type-A connector should go into this end.
  • Step 3: Connect the other end (USB-C) to the relevant port in your laptop.

That’s it You can now just wait or continue using your laptop (charging will take longer).

How To Charge Your Laptop With a Power Bank

Another way to charge your laptop without a charger is to use a powerbank. A fully charged powerbank is basically a spare battery waiting to transfer power to a weakening device.

Note, however, that you need to consider the power your laptop needs and the power the powerbank provides. For example, normal powerbanks meant for smaller devices have an output power of about 5V. However, a laptop may require an output power of 15-20 V.

So it’s a good idea to buy a powerbank that outputs around 20 V. Yes, they’re more expensive, but they’re much better suited for larger devices. The MAXOAK 50000 is a real power bank designed specifically for your high charging needs. The RAV USB Power Bank has a smaller capacity, but offers full portability.

Once you have a powerbank of your choice, all you have to do is plug in the cord to get your laptop charged. The only downside to a powerbank is that it’ll run out of power once you’ve charged your device a few times.

So it’s the best alternative for emergency situations where there are no other options.


We hope this brief but informative article has prepared you for those times of need when your charger lets you down. If it has helped you in any way, feel free to share it with your friends and family.

Do you know of any other methods to charge your laptop with a USB cable? Let’s know in the comments what alternatives you know. If you’re lucky, we might include your suggestions in our next article.

Chris Martin is a professional tech writer. He's been covering tech tutorials, hardware reviews, and more as a professional writer for over seven years now and it doesn't look like he'll be stopping anytime soon! In addition to writing about the latest gadgets on the market, he also covers topics such as how to set up your home network or troubleshoot any computer problems you may have.

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