The feasibility of using a mobile phone charger for a laptop is contingent upon the connection type and the power delivery specifications of both the charger and the laptop. The practice has become increasingly relevant with the widespread adoption of the USB-C standard.
Fundamentally, if a laptop supports charging via a USB-C port, it is often possible to use a USB-C phone charger to provide it with power. However, there are critical differences between chargers designed for phones and those designed for laptops, primarily concerning their power output, measured in watts. Laptops have significantly higher power requirements than smartphones. A typical phone charger may offer 5 to 25 watts, whereas a laptop charger usually provides 45 to 100 watts or more.
When a lower-wattage phone charger is connected to a laptop, several outcomes are possible. The charger may provide enough power to slowly charge the laptop, especially if the device is turned off or in sleep mode. If the laptop is in use, the charger might only be able to slow the rate of battery drain rather than actively increasing the charge. In some cases, particularly with high-performance laptops, the power provided by the phone charger may be insufficient to register as a charging source at all. Therefore, while charging a laptop with a phone charger is technically possible with USB-C, its effectiveness is determined by the charger's power output and the laptop's specific power demands.
