Can Your Laptop's USB-C Charger Juice Up Your Phone?
The Rise of USB-C
USB-C chargers are now ubiquitous, found in everything from smartphones to laptops. This shift has led some phone manufacturers to exclude chargers from new phone boxes. However, laptops still typically come with their own chargers, often USB-C ones, such as MacBooks, Chromebooks, and many Windows laptops.
Cross-Device Charging: Laptop Charger for Your Phone?
Can you use your laptop's USB-C charger to charge your phone?
The answer is yes, especially for phones made in the last few years. But how does this work? What charging speeds can you expect? Will your phone's fast charging feature work? And is it safe to use your laptop's powerful charger on your phone every day?
How USB-PD Makes It Possible
Charging your phone with your laptop's USB-C charger is generally fine. The process is straightforward if both devices support USB-PD (USB Power Delivery). This standard, created by the USB Implementers Forum, allows the charger and phone to determine the best charging power. The charger then starts charging the phone at the highest safe power level.
Daily Use and Compatibility
You can use this setup daily. USB-PD makes it easy to charge any USB-PD-capable device, such as phones, tablets, or gaming consoles, with any USB-PD charger. So, your phone can be charged by any USB-PD charger, whether it came with another phone, a laptop, or a gaming console.
Widespread Support for USB-PD
As USB-C becomes more common, more devices support USB-PD. For example:
- Recent iPhones
- MacBooks
- iPads
- Google Pixel phones
- Samsung Galaxy devices
- Almost all Chromebooks
Many Windows laptops and Android smartphones also support USB-PD.
Non-USB-PD Devices: What to Expect
Things get a bit tricky if one or both devices don't support USB-PD. It's still safe to charge your phone with a USB-C laptop charger if one or both devices don't support USB-PD, as long as they follow basic USB-C specs.
If the charger supports USB-PD but the phone doesn't, the charger will default to a safe lower power mode, supplying only 5V. The current can be 1.5A or 3A, resulting in charging speeds of up to 7.5W or 15W. The USB-PD standard's safety features ensure that a higher voltage is never applied unless the phone asks for it.
If the laptop charger doesn't support USB-PD, it will usually default to 5V. The phone will detect the current via the resistor configuration of the Configuration Channel (CC) pins on the charger. The maximum supplied current is 3A, resulting in a charging rate of up to 15W. So, if neither the laptop charger nor the phone supports USB-PD, you probably won't get fast charging or faster than 15W.
Safety and Quality
If you're unsure whether the charger or phone is compliant with USB-C specifications, it's best to avoid using the laptop charger to charge your phone to reduce risk. Finally, always use a high-quality USB-C cable to charge your phone, as the cable can also affect the charging process and speed.
