# What’s draining my Mac’s battery? How to find it, and what helps

Canonical page: https://vitalsmac.com/mac-battery-draining-fast

By Atta Ur Rehman Shah, maker of Vitals. Published September 29, 2026.

**Short answer:** Click the battery icon in the menu bar: it lists the apps Using Significant Energy. For the full picture, open Activity Monitor, click Energy and sort by Energy Impact for right now, or by 12 hr Power for the last 12 hours. System Settings → Battery shows when the charge fell. The usual causes are an app keeping the CPU busy, indexing after a macOS update, a bright screen, something keeping the Mac awake, and a worn battery. Vitals, a system monitor for the Mac, ranks the apps that used the most energy over the last hours or 30 days, and lists the apps keeping a MacBook awake.

## How to find what is draining the battery

1. Click the battery icon in the menu bar. Apps listed under Using Significant Energy are the first suspects.
2. Open Activity Monitor (press ⌘Space and type its name) and click the Energy tab.
3. Click the Energy Impact column to sort by it. The top rows are using the most power right now.
4. Click 12 hr Power instead to sort by the average over the last 12 hours, or since the Mac started if that is shorter. Use it when the drain happened earlier in the day.
5. Look at the Preventing Sleep column. Yes means the app is keeping the Mac awake.
6. Open System Settings → Battery. The Battery Level chart shows when the charge fell, over the last 24 hours or 10 days, and Screen On Usage shows whether you were using the Mac at the time.

If nothing in Activity Monitor stands out and the battery still empties quickly, check its health in System Settings → Battery → Battery Health. A worn battery holds less, so a normal load empties it faster.

A MacBook that lasted all day and now lasts an afternoon has usually changed in one of a few ways: something new is using the CPU, macOS is catching up on work after an update, the Mac is not sleeping when it should, or the battery has aged. Each one leaves a different trace, and Apple’s own tools can show all of them. The table below matches the symptom to the likely cause and where to look.

## Why a Mac battery drains fast

| What you notice | Likely cause | Where to check |
|---|---|---|
| Drains fast while you work, with a warm case or the fans running | An app or a browser tab keeping the CPU busy | Activity Monitor → Energy, sorted by Energy Impact |
| Drains fast for a day or two after a macOS update | Spotlight, Photos and other background work catching up | Activity Monitor → CPU: mds_stores, photoanalysisd, mediaanalysisd |
| Loses charge overnight with the lid closed | Something waking the Mac or keeping it awake | Activity Monitor → Energy → Preventing Sleep, or `pmset -g assertions` in Terminal |
| Drains fast with an external display or video playing | The GPU and the displays | Activity Monitor → Window → GPU History |
| Lasts a little less every month | Battery wear | System Settings → Battery → Battery Health |
| Drains fast even during light work | Screen brightness, which is often the largest single draw | Control Center → Display |

## Reading the Energy tab

[Energy Impact](https://vitalsmac.com/glossary/energy-impact) is a relative measure of the power an app is drawing now, not a unit like watts. Compare apps with each other: an app at 40 is drawing far more than one at 2, and a figure that stays high while you are not using the app is the one to look at. Browsers show their tabs as separate [helper processes](https://vitalsmac.com/glossary/helper-processes), so a single busy tab can sit near the top under the site’s address or a name like Google Chrome Helper (Renderer).

The graph at the bottom of the tab shows the battery level over the last 12 hours, with the time remaining and how long the Mac has been on battery. A slope that turns steep at one point tells you when the drain started, and the 12 hr Power column tells you which app was busy around then.

## When the battery drains while the Mac is asleep

A Mac that loses 20% overnight with the lid closed is usually not fully asleep. An app can hold the Mac awake, which Activity Monitor shows in the Preventing Sleep column, and some settings let the Mac wake briefly on its own. [Why won’t my Mac sleep](https://vitalsmac.com/mac-wont-sleep) goes further; these are the quick checks.

1. Before closing the lid, open Terminal and run `pmset -g assertions`. Lines that name an app with PreventUserIdleSystemSleep or PreventSystemSleep are keeping the Mac awake.
2. Quit that app, or let it finish what it is doing: a download, a backup, or a call left open in a browser tab.
3. Open System Settings → Battery → Options and set Wake for network access to Only on Power Adapter or Never.
4. Unplug USB and Thunderbolt devices you do not need overnight. Some can wake the Mac or keep it from sleeping.

## When the battery itself is the problem

Open System Settings → Battery and click the info button next to Battery Health. It shows the condition, Normal or Service Recommended, and the Maximum Capacity: how much charge the battery holds compared with when it was new. For the cycle count, hold Option, choose Apple menu → System Information, and click Power.

Apple rates the batteries in recent MacBooks for 1,000 cycles. A battery near that count, or with Maximum Capacity around 80% or below, holds noticeably less, so the same work empties it sooner. No setting fixes that. Apple or an Apple Authorized Service Provider can replace it.

## What actually helps

Most of the gain comes from finding the one thing that changed and dealing with it. General tips help less than they promise.

- Quit or update the app at the top of the Energy tab, or close the browser tab that is busy.
- After a macOS update, leave the Mac on power for a few hours so [Spotlight](https://vitalsmac.com/glossary/spotlight-indexing) and [photoanalysisd](https://vitalsmac.com/glossary/photoanalysisd) can finish while plugged in.
- Lower the screen brightness. It costs power every minute the screen is on.
- When you need the charge to last, set Low Power Mode to Only on Battery in System Settings → Battery.
- Skip battery saver and cleaner apps. Quitting apps you are still using and deleting caches does not extend battery life, and an extra app running in the background uses power of its own.

## What Vitals adds

On a MacBook, Vitals ranks apps by the energy they used, and names the ones keeping it awake.

- Every app sorted by the power it draws, helpers counted in, next to the charge, the watts going in or out, Maximum Capacity and the cycle count
- Keeping This Mac Awake: the apps holding sleep off, why in plain words, for how long, and whether the screen too. In the menu bar dropdown while one is
- 30 days of energy per app: Over Time → Energy ranks apps over the last hour, 12 or 24 hours, 7 or 30 days, even an app you have since quit

Good to know:

- Per-app power is the energy the CPU spent on each app, measured on Apple silicon. The display, the GPU and the radios are not split by app. On Intel Macs the figure is an estimate.
- Apps are ranked hour by hour for the last two days, and by whole days before that.
- The awake list leaves out macOS’s own processes, which hold sleep off for moments at a time. `pmset -g assertions` shows everything.
- Vitals does not send battery alerts.

Vitals is $9 during the launch, $29 after it, once: [vitalsmac.com](https://vitalsmac.com/).

## Questions people ask

### Why is my MacBook battery suddenly draining so fast?

Usually because something changed: a macOS update that set off indexing, a new app or browser extension, or a process that got stuck. Open Activity Monitor’s Energy tab and sort by 12 hr Power to see what has been busy. If nothing stands out, check Battery Health in System Settings → Battery.

### How do I see which apps are using my battery on a Mac?

Click the battery icon in the menu bar for the apps Using Significant Energy, or open Activity Monitor and click Energy. Energy Impact shows the power each app draws now, and 12 hr Power the average over the last 12 hours.

### Why does my Mac battery drain while it is asleep?

Something is waking it or keeping it awake: an app holding a sleep assertion, Wake for network access, or a connected device. Run `pmset -g assertions` in Terminal to see which app, and set Wake for network access to Only on Power Adapter in System Settings → Battery → Options.

### How do I check my MacBook battery health?

Open System Settings → Battery and click the info button next to Battery Health. It shows the condition and the Maximum Capacity. The cycle count is in System Information → Power.

### Does Low Power Mode help on a Mac?

Yes, when you need the charge to last. It lowers the power the Mac uses, at the cost of some speed. Turn it on in System Settings → Battery, set to Always or Only on Battery.

### Is there an app that shows what is draining my MacBook’s battery?

Vitals ranks apps by the energy they used over the last hour, 12 or 24 hours, 7 or 30 days, and lists the apps keeping the MacBook awake, with the reason each gives.

In the glossary: [Energy Impact](https://vitalsmac.com/glossary/energy-impact), [Preventing Sleep](https://vitalsmac.com/glossary/preventing-sleep), [Idle Wake Ups](https://vitalsmac.com/glossary/idle-wake-ups), [App Nap](https://vitalsmac.com/glossary/app-nap), [mds_stores and mdworker](https://vitalsmac.com/glossary/spotlight-indexing), [photoanalysisd](https://vitalsmac.com/glossary/photoanalysisd).

More guides: [Why is my Mac so slow](https://vitalsmac.com/why-is-my-mac-so-slow), [Which app is using my CPU or memory](https://vitalsmac.com/check-cpu-memory-usage-mac), [Why won’t my Mac sleep](https://vitalsmac.com/mac-wont-sleep), [Chrome using too much memory](https://vitalsmac.com/chrome-using-too-much-memory-mac), [Why are my Mac’s fans so loud](https://vitalsmac.com/mac-fan-loud), [How to control fan speed on a Mac](https://vitalsmac.com/mac-fan-control), [How to free up RAM on a Mac](https://vitalsmac.com/free-up-ram-mac), [Docker using too much memory](https://vitalsmac.com/docker-using-too-much-memory-mac), [How to stop Docker containers](https://vitalsmac.com/stop-docker-containers-mac), [Volume mixer for Mac](https://vitalsmac.com/mac-volume-mixer), [Activity Monitor alternatives](https://vitalsmac.com/best-activity-monitor-alternatives), [iStat Menus alternatives](https://vitalsmac.com/best-istat-menus-alternatives), [Stats alternatives](https://vitalsmac.com/best-stats-alternatives), [Task Manager for Mac](https://vitalsmac.com/task-manager-for-mac), [Best system monitors for Mac](https://vitalsmac.com/best-system-monitor-for-mac), [Best menu bar monitors for Mac](https://vitalsmac.com/best-menu-bar-system-monitor-for-mac), [Best volume mixers for Mac](https://vitalsmac.com/best-volume-mixer-for-mac).