Samsung's latest Galaxy S21 devices all offer reverse wireless charging - which Samsung now calls wireless power sharing.

The feature itself isn't new - Samsung originally launched on it on S10 range and reverse charging is available on a number of other devices too now - but you might be wondering how to use your Galaxy S21 to charge your smartwatch or your friend's iPhone, for example. 

This is what you need to know to get some juice from your Galaxy S21 into another device. 

What devices can be charged using the Galaxy S21?

Any device - smartphone or wearable - that supports Qi wireless charging can be charged with the Galaxy S21. 

This includes Apple iPhones from the iPhone 8 and newer, any Android device with wireless charging, as well as Samsung's Galaxy Buds, or the Galaxy Watch 3 for example. 

How to charge a device using wireless power sharing 

To start charging a device using the Galaxy S21, you'll need to unlock your Galaxy S21 and pull down the Quick Settings pane from the top of the screen with a double swipe.

The wireless power sharing icon is a battery with an arrow in it. Tap on the icon to turn it blue and your Galaxy S21 device is ready to share its battery. If you don't have the option in your Quick Settings pane, then you can add it by editing the buttons in the menu top right.

Once turned on, place the device you want to charge on the back of your Galaxy S21 and charging will begin. You'll get a haptic buzz and a confirmation tone to confirm the device is in the correct location.

Samsung Galaxy S10 PowerShare How to charge another device using your smartphone photo 2
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Things to watch out for

For smartphones, devices need to be back-to-back while for smartwatches, you'll need to make sure the underside of the casing is touching the glass back of the Galaxy S21. There will be a haptic buzz and a tone to confirm it's correctly placed.

The two devices need to be in contact all the time to charge. If you remove contact, charging will stop until you reconnect them. You will also have to have over 30 per cent charge in your Galaxy phone before you start.

To find out more about the Galaxy S21 devices and the other features they offer, have a look at our reviews.