Apple's CarPlay system offers a convenient way to run navigation, messaging and music apps on a car's infotainment screen, but it can significantly drain an iPhone's battery because all the processing happens on the phone rather than the car itself. This matters for drivers on long journeys, since prolonged use of apps like Waze or Spotify can noticeably deplete battery life, particularly when connected wirelessly rather than via a cable.

The drain occurs because the iPhone renders the entire interface and streams it to the car's display, unlike Bluetooth audio which barely taxes the processor. Wireless connections make things worse since the phone isn't charging while it powers CarPlay, and battery-hungry apps such as GPS navigation and music streaming, especially in areas with poor signal, add further strain. Engadget recommends using a wired connection where possible, enabling Low Power Mode, using a wireless charging pad if available, downloading music and podcasts in advance, avoiding navigation on familiar routes, and keeping iOS updated to benefit from Apple's efficiency improvements.