It's been rumoured for some time that Apple is working on an external power bank that will attach to the back of 12-series iPhones magnetically, using the MagSafe feature. But nothing is certain, and last month our US colleagues outlined several reasons why this product, referred to by many as the "MagSafe battery", might never arrive.

There is now further reason to hope that the battery will one day hit the market. The well-known Apple leaker Jon Prosser has revealed new information about the product; in his podcast Genius Bar, he claims that a version of the device will offer reverse charging.

Reverse charging is a feature already offered by various Samsung smartphones, whereby other devices such as Bluetooth headphones or smartwatches can be inductively charged via the back of a smartphone. In this case, it would be possible to charge a pair of AirPods (if equipped with a wireless charging case) or an Apple Watch by placing it on the back of the battery, on the back of the iPhone - although we should stress that we are now in the realm of speculation.

According to Prosser, Apple is working on two versions of the MagSafe battery: a standard version, plus a premium version with the reverse charging feature. But his source is unsure whether Apple will actually bring both versions to market.

If you can't wait for Apple to release the MagSafe battery pack - assuming it ever does - then read our guide to the best iPhone power banks for detailed buying advice.

This article originally appeared on Macwelt. Translation by David Price.