USB-C is the order of the day. Recently the European Commission passed the single charger law, and that was the approved standard for it. This means that from 2024 onwards, all consumer electronic devices that need charging will have to have a USB-C port to do so... even the iPhone.

A few days after that, the United States started working on something similar to be implemented on Uncle Sam's land.

The truth is that many people start to have doubts about this standard, and one of the most frequent doubts is: can we use the USB-C charger of our laptop to charge our smartphone? And the answer is simple, generally speaking yes .

However, as you may have noticed, I used the expression “in a general way” here. This is because, ultimately, it will always depend on which charger we are talking about, and which smartphone you are using. In order to have successful charger compatibility (i.e. the ability to use the charger from one device to another device), two conditions must be met: have a common physical link , and use the same charging protocol .

physical connection

In 2014, the USB-C port was officially announced by the USB Implementer's Forum (USB-IF), a non-profit organization that brings together industry-leading companies such as Apple, Microsoft and Intel. USB-C (also called USB Type-C) was conceived with the idea of ​​creating a single universal standard that would solve the many design problems of older USB. Fully reversible, this port would be small enough to be used in smartphones, but still robust enough to power laptops.

Fast forward to the present day, USB-C has become the standard in all types of devices (or almost all). Most new Android phones are powered by this port, and Apple has included it in the Macbook Pro since the 2015 model, and the iPad comes with a USB-C port, which incidentally also shares the spec with the modern Thunderbolt 3. .

charging protocol

But having a physical USB-C port doesn't automatically make everything compatible with everything. This port is simply the physical interface that is bound to the device. In order to have a successful charge, the devices must also have a compatible charging protocol.

Fortunately, if your laptop has a USB-C port, it's also very likely that it supports USB Power Delivery (USB-PD). This is the most common protocol these days, allowing up to 20V/5A (100W) output on laptops. It is also the protocol behind fast charging technologies recently deployed by smartphone manufacturers.

But can I or can I not use my laptop's USB-C charger on my smartphone?

Today, all modern batteries have an integrated charge controller that regulates the input voltage and prevents overcharging. This works in conjunction with the fact that most chargers also support different output voltage levels. In practice, this means that when you connect a charger to a device, the charger itself, and the device, have a kind of “conversation”, where the phone “tells” the charger the voltage it needs, and the input current it needs. supports. The charger then supplies this power at the agreed voltage and current.

USB-C

Precisely because of this negotiation, this means that even if your phone doesn't support fast charging, it will still work with the USB-C laptop charger as the charger will simply assume the standard 5V/1A rate. That is, you can use your laptop charger without problem, it may not have the highest charging speed.

But be careful: always use genuine chargers

All this is real and true, as long as you didn't buy that 5 euro charger in China. Yes, although very rare, there are fake USB-C chargers, that is, they do not meet the USB-IF specifications. I don't think you'll have access to one of these chargers, as they have long since been banned from the market, and from stores worldwide, but in any case, as long as your charger is original, you won't have any problems using it. on any device.