I want to do nothing on my MacBook except watch pre-downloaded MP4 videos.

How can I make the battery last as long as possible in this situation?

I will of course already:

  • screen minimum brightness
  • quit every other app except the MP4 player
  • play in small window not full-screen

What other secret options or configuration can I take advantage of?

4

  • Engage low power mode On your Mac, choose Apple menu > System Preferences, click Battery , click Battery or Power Adapter
  • Putting the video full screen saves the most energy for me for almost all video sources I consume or test
  • Disconnect all accessories (or power down radios like WiFi and Bluetooth to ensure no processes start that could be avoided even though the radio transmitter / receiver / amplifier power savings may be marginal )
  • Enable Optimize video streaming while on battery which lets high-dynamic-range (HDR) video play in standard (SDR) to save energy.

1

  • Re-encode video to be smaller resolution while you still have power source. Less decoding means less CPU time, reducing energy usage
  • Re-encode video to have slower framerate (some HD videos are 60 FPS but 24 FPS might be “good enough”) while you still have power source
  • Re-encode video to use “easier” decoding while you still have power source. For example, H264 over H265 (storage space tradeoff for CPU time)
  • Enter fullscreen, and disable scaling/fit-to-screen (play at original size)
  • Buy external battery pack and use it to charge MacBook
  • Replace internal battery with a new one (especially if battery capacity is failing)

6

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