The new battery cases will cost $129 regardless of which smartphone you're using, and will be available in black or white.
Apple states that the cases will not work with the iPhone X.
The new cases are equipped with Qi-certified chargers, and allow users to charge their iPhone and battery case simultaneously.
The iPhone Xs Max battery case allows for talk time of up to 39 hours, Internet usage of up to 20 hours, or video playback of up to 25 hours.
For the iPhone Xs, these figures are 33 hours, 21 hours, and 25 hours, while the Xr case offers 39 hours, 22 hours, and 27 hours respectively.
The cases can also be charged with USB-PD compatible chargers, and work with Lightning accessories.
