Use Low Power Mode on battery only (or always) — via Apple Support

Hidden settinglow riskmacOS 14 Sonoma and later

Low Power Mode lowers energy use for longer battery life and, on Macs with fans, quieter running, at the cost of some speed. You can set it separately for battery and for the charger, so it only kicks in when you unplug.

Takes effect right away

How to do it

  1. Open System Settings > Battery (or Energy on supported desktop Macs).
  2. Under Energy Mode, set On battery and/or On power adapter to Low Power.
  3. In macOS Sequoia 15.1 and later you can also switch Energy Modes from Control Center.
Which Macs offer Energy Mode (and High Power Mode) depends on the model; Apple's page lists them.

Sources

Source reviewed
2026-11-02
Link checked
2026-11-02
Tested hands-on
Not by Oddbyte.Me

Oddbyte.Me hasn't tried this on every macOS version, so keep the undo handy.

low power modebattery lifeenergy modefan noisemacbook

More in Performance & Power

Check memory pressure, not 'free RAM' — via Apple Support

Tricklow risk

A Mac that shows almost no free memory is usually fine: macOS keeps recently used files cached in RAM so apps reopen faster. The number that matters is the Memory Pressure graph in Activity Monitor, which combines free memory, swap and cached files.