Mac Battery Draining Fast After an Update? How to Fix It

Your Mac battery draining fast right after a macOS update is one of the most common complaints, and also one of the most fixable. In many cases it is temporary background work. In others a rogue app or a setting is to blame. Here is how to tell the difference and what to do about each.

Give it a day or two first

After a major update macOS does a lot of housekeeping: Spotlight re-indexes files, Photos re-analyses your library for faces and objects, and apps update in the background. This work keeps the CPU busy and the battery low. Leave the Mac plugged in overnight, with the lid open if it is a laptop, for a day or two. If battery life is back to normal afterwards, you are done.

Find the culprit in Activity Monitor

1. Open Activity Monitor from Applications, then Utilities.
2. Click the Energy tab and sort by 12 hr Power. Unlike the Energy Impact column, it shows consumption over the last twelve hours, so short spikes do not hide a steady drain.
3. Look for a single app or process far above the others. Browsers, video-call apps and Electron-based apps are frequent offenders.
4. On the CPU tab, sort by % CPU. Processes like mds_stores or photoanalysisd at high CPU are indexing or analysis, which should finish by itself.
5. If an app you do not need is using lots of energy, quit it. If it keeps coming back, check System Settings, then General, then Login Items.

See what is stopping your Mac from sleeping

A battery that drains while the lid is closed usually means something is holding the Mac awake. Run this in Terminal:

pmset -g assertions

Look for entries such as PreventUserIdleSystemSleep or PreventSystemSleep and the process name next to them. A video call app, a download manager or a backup tool is often the cause.

Check battery health

An update can make a worn battery feel worse because background work exposes its limits. Open System Settings, then Battery, and click the info button next to Battery Health. Check the maximum capacity figure and the cycle count. You can also read them in Terminal:

system_profiler SPPowerDataType | grep -E "Cycle Count|Condition|Maximum Capacity"

If the capacity is well below 80 percent, or the condition reads Service Recommended, a battery replacement will do more than any software setting.

Fixes that usually help

• Restart the Mac. Processes that went wrong during the update often settle after a clean boot.
• Install the latest point update. Apple regularly fixes battery bugs in x.1 and x.2 releases.
• Turn on Low Power Mode in System Settings, then Battery, while you work on battery to reduce background activity.
• Lower the screen brightness and turn off the keyboard backlight when you do not need it. The display is the biggest single consumer.
• Update or remove heavy apps. Old versions of apps can misbehave on a new macOS release.
• Close unused browser tabs and switch off extensions you do not use. A handful of tabs running video or animations can drain a battery on their own.
• Disconnect Bluetooth accessories you are not using, since a poorly behaved one can keep the radio busy.

Still draining? Run diagnostics

Run Apple Diagnostics to rule out a hardware fault. On an Apple silicon Mac, shut down, then press and hold the power button until startup options appear, and press Command-D. On an Intel Mac, hold D while the Mac starts. If diagnostics reports a problem, contact Apple Support.

As a last resort, back up with Time Machine and create a new user account to test. If battery life is fine under the new account, the problem is in your profile, such as a login item or a preference file, and not in macOS itself.

Most update-related battery drain comes down to temporary background work or one misbehaving app. Check Activity Monitor, wait out the re-indexing, and the problem usually fixes itself.