As laptops and mobile devices become more advanced and power-efficient, many people wonder whether it is possible to charge a laptop using a phone charger. It might seem convenient, especially if you have forgotten your laptop charger or are trying to minimise the number of cables you carry. While it is technically possible in some situations, it depends heavily on the type of charger, the laptop model and the connection standards used.
This article explores whether a phone charger can be used to charge a laptop, what conditions need to be met, and what risks or limitations are involved. It also looks at the difference between USB charging types, voltage requirements and how to safely charge your device if you are caught without the proper charger.
Understanding USB-C Charging
In recent years, many modern laptops have adopted USB-C as a standard charging port. USB-C is a versatile connector that can carry both data and power, and it is commonly used for phones, tablets and laptops. If both your laptop and phone charger support USB-C, and the charger has enough power output, there is a chance that you can use it to charge your laptop.
However, not all USB-C ports are the same. A USB-C port on your laptop may support charging, but the phone charger also needs to provide sufficient wattage to power the device. Phone chargers usually output around 5 to 20 watts, while laptops typically require 30 to 100 watts or more depending on the model. Charging a high-performance laptop with a low-wattage phone charger may result in very slow charging or may not work at all.
Laptop Power Requirements
Each laptop model has specific power requirements that are set by the manufacturer. You can usually find this information on the original charger label or in the user manual. Ultrabooks and low-power Chromebooks may charge with as little as 30 watts, but gaming laptops or high-performance machines often need 65 watts or more to charge and operate at the same time.
If your phone charger does not meet the voltage and current levels required by your laptop, it may not be able to deliver enough power to charge the battery. In some cases, the laptop might detect the charger but display a warning that it is charging slowly or not at all.
When Can You Use a Phone Charger
If your laptop supports USB-C charging and has lower power requirements, and your phone charger is a USB-C Power Delivery (PD) charger that can output 30 watts or more, you might be able to charge your laptop. This setup is more common with lightweight laptops such as some MacBook Air models, Microsoft Surface devices, or Lenovo ThinkPad X series laptops.
However, even in this best-case scenario, charging may be slower than with the original laptop charger. You may also find that the laptop charges only when it is powered off or in sleep mode because the power draw while in use may exceed the charger’s output.
Why Most Phone Chargers Will Not Work
Most standard phone chargers are designed to power small devices with low energy needs. Basic USB-A chargers, which are still commonly used for older phones, cannot charge a laptop because they do not support the voltage or current needed. Even some newer USB-C phone chargers are capped at 18 or 20 watts, which is far below what most laptops need.
Trying to use an underpowered charger might cause the laptop to reject the connection or display a low-power warning. In rare cases, using an incorrect charger could damage the battery or charging circuit over time.
Using a High-Power USB-C Charger
There are USB-C chargers designed to work with both phones and laptops. These often support USB Power Delivery and provide output ranging from 30 to 100 watts. If you use one of these chargers, you can safely charge compatible laptops and still use the same charger for your phone. Brands like Anker, Aukey and Baseus make multi-purpose USB-C chargers that are compact and travel-friendly.
Always check the specifications before plugging in. Make sure the charger supports the required output and that the cable is also rated for high-wattage charging. Using a cheap or under-rated USB-C cable can lead to overheating or failure to charge.
Emergency Charging Options
If you are stuck without your laptop charger and have no other option, using a high-wattage USB-C phone charger could help in an emergency, especially to prevent the battery from running flat. It is not a long-term solution, and it is not guaranteed to work on all models, but it might be enough to finish a task or send an important email before the battery dies.
Another emergency option is to use a USB-C power bank that supports laptop-level output. Some power banks are designed specifically for laptops and come with high-wattage USB-C ports that can safely charge your machine on the go.
Conclusion
You can charge a laptop with a phone charger only if the laptop supports USB-C charging and the phone charger provides enough power to meet the laptop’s needs. For low-power laptops and high-wattage USB-C chargers, this may be possible, although not ideal. In most cases, a standard phone charger will not be powerful enough to charge a laptop effectively or safely. It is always best to use the original charger or a proper replacement that meets the manufacturer’s specifications to avoid performance issues or hardware damage.