Talk time up to 37 hours*
Internet use up to 20 hours*
Video playback up to 25 hours*
* Testing conducted by Apple in November 2018 using preproduction iPhone XS Max units and software paired with preproduction iPhone XS Max Smart Battery Case units and preproduction software. Talk time tests were conducted over a Voice over LTE (VoLTE) network.
* Internet tests were conducted over LTE and Wi-Fi networks using a dedicated web server, browsing snapshot versions of 20 popular web pages and receiving mail once an hour. Video tests consisted of repeated playback of a 2-hour 23-minute movie purchased from the iTunes Store.
* All settings were default except: Bluetooth was paired with headphones; Wi-Fi was associated with a network for all but the Internet LTE test; the Wi-Fi feature Ask to Join Networks, Auto-Brightness, and True Tone were turned off.
* All battery claims depend on network configuration and many other factors; actual results will vary.