Apple has been granted a patent (number 9,826,301) for an AirPod case with an inductive charging system that includes a rechargeable battery and a first and a second charging system. It involves Apple’s upcoming AirPower wireless charging mat that’s due in 2018.
An updated version of the AirPods case will include wireless charging. It's rumored that Apple will sell the case separately for $69 by the end of 2017.
Per the Apple patent, the first charging system is configured to charge the smartphone. The second charging system is configured to wirelessly charge the iPhone positioned outside of the case adjacent to an exterior charging surface.
In the patent filing, Apple notes that, while wireless portable listening devices have many advantages over wired devices, they also have some potential drawbacks. For example, wireless portable listening devices, typically require one or more batteries, such as a rechargeable battery, that provides power to the wireless communication circuitry and other components of the device. Single use batteries need to be replaced when their charge is depleted while rechargeable batteries need to be periodically recharged.
Also, if the portable wireless listening device is a pair of wireless earbuds, the earbuds can be relatively small and easy to lose when not in use. Further, achieving high-end acoustic performance from the relatively small earbuds can challenge manufacturers due to the reduced amount of space available within each earbud.
Of course, Apple files for — and is granted — lots of patents by the U.S. Patent & Trademark Office. Many are for inventions that never see the light of day. However, you never can tell which ones will materialize in a real product.