Apple just launched three new smart battery cases for its newest iPhones. It's the first time Apple has launched a battery case since the one it first began selling for the iPhone 6/iPhone 6s.

The cases are available in either black or white and can be purchased for the iPhone XS, the iPhone XS Max and the iPhone XR. They add battery life but make the phone a bit thicker. They also work with wireless chargers, so you can drop them on a charging pad to juice them up instead of plugging them in.

Apple says the iPhone XS case offers up to 21 hours of internet use or 25 hours of video playback, the iPhone XS Max case offers up to 20 hours of internet use or 25 hours of video playback, and the iPhone XR case offers up to 22 hours of internet use or 27 hours of video playback.

The cases can be ordered now and will be available in stores on Jan. 18.

WATCH: CNBC's Todd Haselton's iPhone XR review