Start here: a two-minute check
- Open Activity Monitor (Applications › Utilities) and click the Energy tab.
- Sort by Energy Impact. Apple describes it as a relative measure of an app's current energy use; lower is better. Anything near the top that you aren't actively using is a suspect.
- Check 12 hr Power. This column shows each app's average energy impact over the last 12 hours, or since your Mac started. It catches apps that drain in bursts when you're not watching.
- Check Preventing Sleep. A "Yes" means that app is stopping your Mac from sleeping, which drains the battery with the lid open and the screen off.
Quitting the worst offender often fixes the problem. If an app keeps returning to the top, look for an update or a setting that reduces its background work. (Source: Apple, View energy consumption in Activity Monitor.)
The usual suspects
Browsers with many tabs
Every open tab can run scripts, play media and refresh in the background. Video sites, web apps and pages with lots of ads cost the most. Close tabs you don't need, and check your browser's own task manager for the heaviest ones.
Video calls and screen sharing
Calls keep the camera, microphone, network and video encoder busy at once. An hour-long call can use a noticeable share of a charge, especially with background effects turned on.
Indexing after an update or migration
After a big macOS update, or after moving to a new Mac, macOS often re-indexes your files for Spotlight and analyzes your photo library. This background work can take a day or two and settles on its own. Leaving your Mac plugged in and awake for a while helps it finish.
Sync, backup and helper apps
Cloud sync clients, backup tools, updaters and launchers run in the background and can start automatically at login. Check System Settings › General › Login Items & Extensions for things you don't need any more.
A runaway process
Sometimes an app gets stuck at full CPU. You'll notice warmth and fan noise (on Macs with fans), and it'll be at the top of Activity Monitor's CPU tab. Quit it, or Force Quit if it won't respond.
Settings that make a real difference
- Screen brightness. The display is one of the biggest power users. Apple recommends dimming it to the lowest comfortable level for maximum battery life.
- Wi-Fi and accessories. Apple notes that Wi-Fi uses power even when you're not connected to a network, and suggests disconnecting peripherals and quitting apps you aren't using.
- Low Power Mode. In System Settings › Battery, choose Low Power Mode for when you're on battery. Apple says it reduces energy use to increase battery life. (See Apple, About Power Modes.)
- Keyboard backlight. Turn it off in bright rooms, or let it switch off after a few seconds of inactivity in System Settings › Keyboard.
(Source for brightness and Wi-Fi: Apple, Batteries – Maximizing Performance.)
Heat makes everything worse
Apple says MacBooks work best at ambient temperatures of 10° to 35° C (50° to 95° F), and that higher temperatures can permanently damage battery capacity. A hot Mac also runs its chips harder to do the same work. Avoid using it on a bed or cushion that blocks airflow, and keep it out of the sun and hot cars.
Is it the battery?
Batteries wear with use. If your Mac drains fast even when nothing is busy, check the battery itself:
- Open System Settings › Battery and look at Battery Health. Click the info button for details.
- "Normal" means the battery is working as expected. "Service Recommended" means it holds less charge than when new, or isn't working normally. Your Mac is still safe to use (Apple).
- Check the cycle count in System Information › Power. Apple rates the batteries in MacBook Air models from 2020 onward and MacBook Pro models from 2021 onward for 1,000 cycles, designed to keep up to 80% of their original capacity at that point (Apple).
If your battery is worn and the shorter runtime bothers you, Apple or an Apple Authorized Service Provider can replace it. Apple recommends relying on the battery health macOS reports when deciding.
Quick reference
| What you notice | Likely cause | What to try |
|---|---|---|
| Drains fast with the lid closed | Something preventing sleep | Activity Monitor › Energy › Preventing Sleep |
| Warm, fans running, slow | A runaway app | Activity Monitor › CPU, quit the top app |
| Worse since a macOS update | Indexing and photo analysis | Wait a day or two, plugged in |
| Worse every month | Battery wear | Check Battery Health and cycle count |
| Worse only on calls or video | Camera, encoder and network all busy | Lower brightness, turn off video effects |
How Tend helps
Activity Monitor's Energy Impact is a relative score. Tend measures your Mac's total power draw and estimates each app's share in watts, so the biggest drain sits at the top of the list. It keeps the last 24 hours free, and 30 days with Pro, so you can see what drained your battery yesterday. Pro can also alert you when an app stays above 80% CPU for 5 minutes, or uses more than 4 W while you're on battery. It's free to download, and Pro is free during the beta.