Disclosure up front: I make BatteryMeter, the free app in section 4. It costs nothing and has no paid tier, but it is my product, so weigh that. No link on this page is an affiliate link. The built-in steps below are what Apple's support pages say. I did not take screenshots for this guide, so check the labels against your own Mac.
The short answer
Click the battery icon in the menu bar. If an app is using significant energy, macOS lists it there. For a full list, open Activity Monitor and click Energy. The app at the top of the Energy Impact column is using the most energy right now, and the 12 hr Power column shows which app has used the most over the last 12 hours.
If no app stands out, look at the battery itself. Apple notes that a battery's ability to hold a charge may be less than when it was new (Apple's page on a battery that runs out quickly).
1. The battery menu
This is the quickest check and needs no app.
- Click the battery icon in the menu bar. If you do not see it, open System Settings, click Menu Bar and select Battery (Apple's page on the battery status).
- Read the list of apps under the charge level. Apple says the menu shows which apps, if any, are using a lot of energy (Apple's page on the Battery Status menu).
- If an app you are not using shows up, quit it. Apple suggests closing an app that uses significant energy when you are not using it, particularly on battery power.
An empty list does not mean nothing is using energy. The menu names only apps, and only the ones using a lot. For background processes and a full ranking, use Activity Monitor.
2. Activity Monitor, Energy tab
Activity Monitor is in Applications, inside the Utilities folder. Open it and click Energy at the top of the window (Apple's page on the Energy pane). Click a column heading to sort by it.
| Column | What Apple says it shows | How to use it |
|---|---|---|
| Energy Impact | A relative measure of the app's current energy use. Lower is better. | Sort high to low to see what is using energy now. It is a score for comparing apps in the same list, not watts. |
| 12 hr Power | The app's average energy impact over the last 12 hours, or since the Mac started. Lower is better. Shown on Mac laptops only. | Sort by it to find the app that has used the most over the day, not just in the last few seconds. |
| Preventing Sleep | Whether the app is stopping the Mac from going to sleep. | An app that keeps the Mac awake keeps using the battery while you are away. |
The bottom of the window shows the remaining charge, the time remaining, the time since you unplugged, and a chart of the battery level over the last 12 hours. On a desktop Mac, the 12 hr Power column and these battery details do not appear.
Quit apps you recognise. If you do not know what a process is, look it up before you quit it, because some belong to macOS.
3. Battery settings, last 24 hours
The first two checks show what is happening now. Battery settings show the pattern. Choose Apple menu, System Settings, then Battery (Apple's page on Battery settings). Apple lists these charts:
- Last 24 Hours, Battery Level: the average charge for each 15-minute period. Shaded areas mark when the Mac was charging.
- Last 24 Hours, Screen On Usage: how long the screen was on each hour.
- Last 10 Days, Energy Usage: how much energy the Mac used each day.
Read the two 24-hour charts together. A steep fall in battery level while the screen was on likely means heavy use, such as a video call. A fall while the screen was off points to something working in the background, or to a Mac that did not sleep. Go back to Activity Monitor and sort by 12 hr Power and Preventing Sleep.
Drains that do not look like an app
Some causes show up under names you may not recognise, or not at all. Each line below repeats what Apple's own page says.
- Spotlight indexing after an update. Spotlight indexes your Mac after you install a software update or upgrade, and that can take hours or even days, depending on how much data is on the Mac. Apple says indexing finishes sooner when the Mac is not in use and is connected to power. Press Command-Space: while indexing runs, a progress indicator shows at the top of the Spotlight window (Apple's page on Spotlight indexing). If the drain started right after an update, plug in and let indexing finish before you look further.
- kernel_task. A system process with this name can show high CPU use, often with more fan noise. Apple says one of its jobs is to manage CPU temperature by making the CPU less available to processes that use it heavily, and that it does not cause the heat itself. It slows down again once the CPU cools (Apple's page on kernel_task). Find the app that is working hard and quit that one.
- Apps and accessories you are not using. Apple says an app you are not using may still be working in the background and using energy, and suggests disconnecting accessories you are not using, such as external hard drives (Apple's page).
4. A free menu-bar list: BatteryMeter
BatteryMeter is a free menu-bar app I make. Its Using the most power section lists the top five apps and background processes by energy impact. Like the Activity Monitor column, that is a relative score and not watts. You can quit or force quit your own processes from the list, and system processes such as kernel_task show no quit option. The menu bar also shows the battery's power in watts, so you can watch the drain change after you quit something.
It needs macOS 13 or later on Apple silicon, and it is for MacBooks, since it reads the battery. It is free with no account, email or trial. Once a day it checks for a newer version of itself and sends nothing else, and a menu item turns that check off. Its chart covers the last hour only, so use the 12 hr Power column and Battery settings for the longer view.
When it is the battery, not an app
If no app stands out and the Mac still runs out sooner than it used to, check the battery's condition. In System Settings, Battery, the Battery Health line reads normal or service recommended, and Maximum Capacity shows the battery's capacity compared with when it was new (Apple's page on Battery settings). For the cycle count, voltage and charger watts, follow how to check a Mac's battery health, voltage and cycle count.
Frequently asked
Is Energy Impact in Activity Monitor the same as watts?
No. Apple describes Energy Impact as a relative measure of an app's current energy use, where lower is better. Use it to compare apps in the same list. It does not convert to watts or to a percent of battery.
Why does kernel_task use so much energy?
Apple says one of kernel_task's jobs is to manage CPU temperature by making the CPU less available to processes that use it heavily. It responds to heat and does not cause it, and it slows down once the CPU cools. Find and quit the app that is using the CPU heavily, not kernel_task.
Does Low Power Mode help?
Apple describes Low Power Mode as a setting that reduces energy use to increase battery life, and lists it among the steps to try when the battery runs out quickly. Turn it on in System Settings, Battery. It does not stop a busy app, so quit that app as well.
Related guides
- Check your Mac battery health, cycle count, voltage and charger watts: read the battery's own numbers with built-in tools, with real output.
- Why is System Data so big on my Mac?: another look at what macOS keeps on the disk in the background.
- All guides.