A neat trick just caught attention on the forums: if you own an iPhone with a USB-C port (such as the iPhone 15 or later), you can use that iPhone to charge your Apple Watch by plugging the watch’s magnetic charging cable into the iPhone’s USB-C port. According to Apple’s support documentation, the phone is capable of charging small accessories including the Apple Watch, albeit at a modest power level.
To make this work you need the correct hardware: the watch must be connected via its USB-C magnetic charger (or if you have an older watch cable then a USB-C to USB-A adapter), and the iPhone must be one of the newer models that supports powering accessories through USB-C.
Once you connect the cable, the watch begins to receive power from the phone. It’s not fast, but it’s enough to rescue the watch when its battery is about to die and you don’t have a wall charger nearby.
What You Should Know Before Trying It
The output power is capped at around 4.5 watts, which is low compared to what a wall charger can deliver. Because of that limit you should think of this method as an emergency option, not a regular way to charge your watch. If you rely on full speed charging, you still need the original wall charger or Apple’s fast charger puck for the watch.
One important limitation is that you cannot just place the Apple Watch on the back of the iPhone and expect wireless charging. The trick requires a cable connection and cannot work via reverse wireless charging on current iPhones. Also, because your iPhone is supplying power, its own battery will drop while it is charging the watch, so make sure the phone has enough charge for your own use.
In short, when your Apple Watch is dying and you’re away from a charger, grab your iPhone, connect the watch puck, and keep going. It won’t be full speed, but it keeps you going.
