To find what is draining your Mac battery, click the battery icon in the menu bar. It lists the apps that use significant energy now. For a ranked list, open Activity Monitor and click Energy. Neither one shows the display, the radios or a charging iPhone, and neither keeps more than 12 hours. Here is each place, and what to do with what you find.
The battery menu
- Click the battery icon in the menu bar.
- Read the list of apps that use significant energy. If no app uses a lot, the list is not there.
This is a quick check. It shows the apps of this moment, with no numbers.
Activity Monitor
- Open Activity Monitor. It is in the Utilities folder in Applications, or search for it with Spotlight.
- Click Energy at the top.
- Click the Energy Impact column to sort by the energy each app uses now.
- Click 12 hr Power to sort by the last 12 hours, or since the Mac started.
Apple calls Energy Impact “a relative measure” of an app’s energy use, where lower is better. It is a score, not watts. The panel at the bottom shows the charge, the time on battery and a chart of the last 12 hours. See what Energy Impact means in Activity Monitor for each column.
The Battery settings
- Open the Apple menu and choose System Settings.
- Click Battery in the sidebar.
- Click Last 10 Days and read the Energy Usage chart.
The chart shows how much energy the Mac used each day. It does not list apps, but it tells you which day was unusual. See how to see battery history on a Mac.
What macOS leaves out
| Question | Battery menu | Activity Monitor | Battery settings |
|---|---|---|---|
| Which apps use energy now | Only heavy users | Yes, as a score | No |
| Which apps used energy yesterday | No | No. 12 hours at most | No |
| How many watts the Mac uses | No | No | No |
| The display, graphics and radios | No | No | No |
| A device charging from a port | No | No | No |
Most of the power is not your apps
The apps in these lists are only part of the drain. The display, the graphics, Wi-Fi and Bluetooth, and macOS itself use power too. At light load they use more than all apps together.
On one MacBook at light load, on October 11, 2026, we measured about 15 W for the whole Mac. The processor energy of all the apps together was 0.5 W. The rest was the screen, the hardware and the system.
So check these before you quit apps:
- Brightness. The display is one of the largest users. Lower the brightness with the keys on the keyboard.
- Devices on the ports. A phone, a drive or a hub takes power from the battery. See does charging an iPhone from a MacBook drain its battery.
- An app that runs in the background. Sort Activity Monitor by 12 hr Power. If an app near the top is one you did not use, check its settings for background work, or quit it.
- Preventing Sleep. In Activity Monitor, the Preventing Sleep column shows apps that keep the Mac awake.
Common causes
| Cause | How to tell | What to do |
|---|---|---|
| A browser with many tabs | The browser and Web Content are near the top in Activity Monitor | Close tabs you do not need |
| A video call | The call app is near the top of Activity Monitor during calls | Turn off the video when you do not need it |
| A sync or backup | A cloud drive or Time Machine is near the top after you add files | Let it finish while the Mac is on power |
| A phone charging from the Mac | The battery drops faster while the cable is connected | Charge the phone from a wall charger instead |
| The battery is old | The charge goes faster than a year ago, with the same use | Check the maximum capacity. See how to check battery health on a Mac |
See where the power went, over hours and months
BatteryBud is a battery monitor for Mac. From version 1.3.0 it has Power flow on MacBooks. It is a map on the page of your Mac. The map starts at the battery or the adapter and splits into Apps, Devices, System and, on the adapter, Charging. Then it splits into the six largest apps, the other apps, each device charging from a port, and System.
- Live, in watts. The total updates every minute, from the battery controller. The apps update every 5 seconds while the map is on screen.
- Over time, in watt-hours. Since you unplugged, the last 24 hours, 7 days, 30 days or 12 months. You can filter to the time on battery or on the adapter.
- Measured or Estimated. Measured shows the processor energy macOS records for each app, and everything else is System. Estimated splits the rest of the Mac’s draw, after devices and charging, between apps and macOS by the score that Activity Monitor ranks by. It marks those figures as estimates.
- In the menu bar. The popover shows the three largest drains under your Mac. Click them to open the full map. You can turn this off in Settings, then General, then Menu bar.
To draw the map, BatteryBud records the energy each app uses. The history stays on your Mac, and it is not shared with your other Macs. In Settings, then General, a switch stops the recording and deletes the history.
Power flow is for MacBooks. A desktop Mac has no battery controller, so BatteryBud cannot measure its total.