Below are practical, high-impact OS settings and habits you can change to extend battery life. I’ve grouped them into general principles first, then quick step-by-step tweaks for common operating systems (Windows, macOS, iOS, Android, Linux). Apply the tradeoffs you’re willing to accept (lower performance or fewer background features for longer battery).

General principles (applies to all devices)

• Lower screen brightness and use auto/ambient brightness when available. The display is almost always the biggest battery user.
• Reduce screen timeout (30–15 seconds for phones; 1–5 minutes for laptops depending on use).
• Use a lower refresh rate (60 Hz) or adaptive refresh if supported.
• Enable any “Battery saver” / “Low power mode” features — these throttle background activity and performance.
• Turn off wireless radios when not needed: Bluetooth, Wi‑Fi, NFC, GPS/Location.
• Limit background app activity and push/sync frequency for email, social apps, and cloud services.
• Use dark mode on OLED screens (phones and some laptop displays) — it can save power.
• Uninstall or disable unused apps and startup programs.
• Use integrated GPU instead of discrete GPU for laptops when possible.
• Keep OS, firmware (BIOS/UEFI), and drivers up to date — efficiency improvements are often included.
• Avoid extreme temperatures. Heat reduces battery efficiency and life.
• For long-term battery health: avoid keeping battery at 100% or 0% for long periods; partial charges (20–80%) are gentler for lithium batteries.

Windows (10 / 11) — quick steps and options

• Open Settings > System > Power & battery:
  • Choose Power mode: “Better battery” or “Battery saver” to prioritize energy savings.
  • Turn on Battery saver (set to activate at e.g., 20%).
  • Reduce Screen and sleep timeouts.
• In Settings > System > Display:
  • Lower brightness, enable Night light only if needed, disable HDR if not needed.
  • Reduce refresh rate in Advanced display settings (if supported).
• Manage background apps: Settings > Privacy & apps (or Apps > Apps & features) → Advanced options for each app → Background apps permissions → Let apps run in background: Off for battery-draining apps.
• Turn off Bluetooth/Wi‑Fi when not needed (quick action center).
• For advanced users: use power plans (Control Panel > Power Options) and set Maximum processor state to e.g., 80–90% on battery to cap CPU power; consider “Balanced” or a custom plan.
• Use integrated GPU in GPU control panel (NVIDIA/AMD) for battery use; or set graphics preference per app in Settings > System > Display > Graphics.

macOS (Monterey, Ventura, later)

• System Settings (or System Preferences) > Battery:
  • Turn on Low Power Mode.
  • Set “Turn display off after” to a short duration.
  • Enable “Slightly dim display while on battery power.”
  • Enable “Optimized battery charging” to improve long-term health.
• Disable Power Nap when on battery (prevents background tasks).
• System Settings > Displays: lower brightness, disable ProMotion / high refresh if you don’t need it.
• Close unneeded apps and remove login items (System Settings > General > Login Items).
• For MacBooks with discrete GPUs: set “Automatic graphics switching” on (older macOS path: Energy Saver).

iOS (iPhone / iPad)

• Settings > Battery:
  • Turn on Low Power Mode.
  • Review Low Battery Mode suggestions and Battery Usage by app; disable background refresh for heavy apps.
• Settings > Display & Brightness: reduce brightness, enable Auto-Brightness, use Dark Mode for OLED devices.
• Settings > General > Background App Refresh: restrict to Wi‑Fi only or turn off for specific apps.
• Settings > Mail / Accounts: set fetch to Manual or increase fetch interval; reduce push.
• Settings > Privacy > Location Services: set apps to “While Using” or “Never” rather than “Always.”
• Turn off unneeded radios: Bluetooth, Wi‑Fi, AirDrop, and set Airplane Mode when you don’t need connectivity.

Android (stock and most OEMs)

• Settings > Battery:
  • Enable Battery Saver / Power Saving mode.
  • Turn on Adaptive Battery (limits background for seldom-used apps).
  • Use App battery usage to put heavy apps to sleep or restrict background activity.
• Settings > Display: lower brightness, enable Adaptive brightness, reduce screen timeout and refresh rate.
• Settings > Apps: restrict background activity or force sleep for specific apps.
• Settings > Location & Privacy: set location access to “While using app” and disable high-accuracy modes if not needed.
• Turn off Bluetooth, NFC, or Wi‑Fi when not needed; disable always-on display features if draining.

Linux (Ubuntu, Fedora, other desktop distributions)

• System Settings > Power (or Power Profiles): choose “Power Saver” / lower performance profile.
• Lower screen brightness and sleep timeouts.
• Use TLP (tlp) and/or powertop for advanced power management (TLP provides sensible defaults; powertop can suggest tunings).
• Disable or unload unused services and background daemons (systemctl disable --now servicename).
• Use integrated GPU and enable CPU frequency scaling governors like “powersave” or “ondemand.”
• For laptops: set SATA/USB autosuspend, bluetooth off when unused.

Advanced tips for power users

• Monitor which processes use the most power: Windows Task Manager (per-app energy impact), macOS Activity Monitor, iOS/Android battery screens, Linux powertop/top.
• Cap CPU max frequency or maximum processor state to reduce peak power draw.
• For laptops with hybrid graphics, force integrated-only mode for max battery life.
• Use hibernate instead of sleep when you won’t use the device for an extended time.
• Reduce or disable notifications and live wallpapers/widgets that wake the display frequently.
• On phones, avoid high-power features like continuous GPS tracking, 5G (if you can switch to 4G), and frequent camera use.

Short checklist you can apply right now

• Reduce brightness, enable auto-brightness
• Enable Battery Saver / Low Power Mode
• Shorten screen timeout
• Turn off Bluetooth/Wi‑Fi/Location when not needed
• Restrict background apps and push/fetch for email/social
• Use dark mode if you have an OLED screen
• Keep OS and firmware updated

If you tell me which device and OS you’re using (e.g., Windows 11 laptop, iPhone 15 on iOS 17, Pixel on Android 14, Ubuntu laptop), I can give step‑by‑step menu paths and specific recommended settings tailored to that device.