Charge your phone from your tablet with Samsung’s new Power Sharing cable

Power banks are getting cheaper and larger, but what if you could use your Samsung tablet or smartphone as an external battery?

That’s the promise of Samsung’s new Power Sharing cable, which does exactly what the name suggests: it allows you to use some of the energy of one device to charge up another.

There’s a catch – only select Samsung devices can be sources. These are, for now: Galaxy S5, Galaxy Tab S 10.5, Galaxy Tab S 8.4, Galaxy Alpha, Galaxy Avant, and Galaxy Note 4. However, any device with a microUSB port can be charged up. Of course, some of the used energy will be lost due to the inherently imperfect efficiency of the process.

The cable features two microUSB plugs, with arrows on the plugs showing the direction the charge “flows.” While the Samsung devices listed above can give a charge simply by plugging in the cable, Samsung published an app that lets you decide how much energy you want to transfer to the other device. The app is now available from the Play Store or from Samsung Apps.

The Power Sharing cable is available on Samsung’s store for $19.99, which isn’t that much to pay for the functionality it offers. Sure, you can get a good size power bank for that money, but the cable could be more useful, depending on the way you use your devices.