Generally speaking, it is safe to leave a MacBook plugged in all the time. A huge number of MacBook usage are in scenarios where a MacBook is sitting on a desk, connected to a charger, and often to an external display, keyboard, and mouse too. These “use a laptop as a desktop” situations are incredibly common in the workplace and school with Apple laptops, and for many home users as well.

When a MacBook is plugged in and charging, it will typically perform at it’s best, since there is no need to engage in energy conservation or battery life extension. It’s not totally unusual for some MacBook users to have discovered their laptop feels like it’s running slower than usual when running on battery particularly when battery life is relatively low, and in fact it often is running slower because of the Low Power Mode feature, which directly throttles performance to extend battery life.

While there’s nothing wrong with keeping a MacBook plugged in all the time, and you’ll often have the best CPU performance by doing so, there are a few things to keep in mind that may contribute to the broader battery health and battery longevity of your MacBook, so it’s important to keep those in mind.

Important considerations for keeping MacBook plugged in

Most modern laptop and gadget batteries are lithium-ion based, including those that are found in MacBooks, which means they degrade over time and with usage. The battery in a MacBook is designed to be used. Keeping a lithium-ion battery at 100% charge constantly may reduce the overall lifespan of a battery, but modern Macs include battery maintenance features that help to prevent this. Nonetheless, it’s still good practice to use your Mac laptop as a laptop from time to time, and let the battery discharge to 20%-30% or so, and then charge it again.

Apple explains the various factors that can contribute to Mac battery health and battery lifespan as follows: “All rechargeable batteries are consumable components that become less effective as they get older—and their age isn’t determined only by time. A battery’s lifespan depends on its chemical age, which is affected by factors such as its temperature history and charging pattern. As your notebook’s battery ages chemically, its charging capacity gets smaller.”

Let’s pay particular attention to the ‘temperature history’ and ‘charging pattern’, because those are both often directly controllable by MacBook users.

Modern versions of MacOS have built-in battery optimization features that aim to extend the lifespan of the devices battery. One of the primary means of doing this is by learning your laptop usage and charging habits, and then delaying the amount of time the MacBook spends fully charged. For example, let’s say you get to your desk every day at 8am, plug in your MacBook, and then leave your desk every day and disconnect the MacBook at 4pm – macOS battery optimization will observe and learn this schedule, and then hold your laptop battery at an 80% charge level until the end of the day, when it will then charge the battery to 100%. Apple Silicon Mac laptop batteries will use fast charging tech to get to 80% capacity, and then they automatically switch over to a slower charging style referred to as ‘trickle charging’, where the remaining 20% will charge much slower, at a defined time, or sometimes not at all.

Battery Optimization is enabled by default on every modern Mac, but you can confirm it is enabled on your particular Mac laptop by going to  Apple menu > System Settings > Battery > Battery Health > clicking the tiny (i) button next to Battery Health make sure “Optimized Battery Charging” is enabled. Battery Optimization should be enabled on Mac laptops for best performance and longevity.

Avoid extreme heat

Extended exposure to high heat or extreme heat can negatively impact battery health and battery life, and it’s also not great for any tech in general. Heat can directly damage lithium-ion batteries. Keep the MacBook Air or MacBook Pro out of direct sunlight, and away from heat sources. Do not smother the laptop, which can prevent heat from dissipating as designed.

Additionally, if you run the MacBook in clamshell mode (meaning closed, but still on and connected to an external display), you will want to make sure it is well ventilated around it, particularly with the modern MacBook Air since it does not include a cooling fan. The fan-less design of the Apple Silicon MacBook Air series makes it a very power efficient and silent computer, but it is known to throttle performance when overheating or in clamshell mode and under heavy usage.

Aside from potential battery issues, high heat will often cause CPU performance to reduce and throttle. If you’ve ever used a MacBook outside in the sun on a warm day, felt the computer get very hot to the touch, and then suddenly become almost unusably slow with beachballs, it’s likely because the Mac is overheating and the system is reducing performance and other activity to try and cool things down. There are a variety of helpful ways to keep a MacBook cool in hot weather and high temperatures if you want more specifics, but a little common sense goes a long way.

Keep macOS updated

It’s important to keep up to date with macOS software updates and install those updates when they are available. Not only do macOS system software updates routinely fix bugs and security issues, they may also address any known issues with energy usage, battery optimization and usage, or other power management related circumstances. You can update macOS by going to  Apple menu > System Settings > General > Software Update.

Window Tiling

With macOS Sequoia, Apple has introduced a new window tiling management feature that aims to make it easy to arrange open windows into a layout that works best for you. When you drag a window to the edge of the screen, ‌macOS Sequoia‌ suggests a tiled position by displaying a frame, and you release the window to drop it right into place. This way, you can quickly arrange two app windows side by side, or place four windows in corners to keep several apps in view at once. When a window has been dragged to tile on one side or the other, dragging it back immediately resizes it to its original width and height.

macOS 15 also adds new tiling options to the green traffic light in the top corner of windows. Hover your pointer over the green button, and a menu appears with options to move and resize or fill and arrange all open windows.

Safari Video Viewer

When watching a video in Safari, click the menu icon in the left-hand side of the address bar and select the new Video Viewer option. This makes the playing video expand within the Safari window into a kind of theater mode that blurs everything out behind it, bringing the content front and center.

It also includes a native playback controls interface that replaces YouTube's – or the UI of whatever video you are playing. Options include AirPlay, volume, Picture in Picture, and playback speed.

Move & Resize Windows Controls

Accessed from the menu bar, a new "Move & Resize" option in the Window menu allows you to easily manage and arrange windows on your screen by offering various tiling and resizing options. You can move a window to the top, bottom, left, or right half of the screen, or position it into one of the four corners if you prefer a quarter-screen layout.

macOS also provides more flexible arrangements, such as splitting the screen horizontally or vertically, where you can tile windows side by side or one above the other. For even more control, there's a feature to quickly return a window to its previous size and position, making it easy to undo any changes.

iPhone Notifications

In System Settings > Notifications, there's an "Allow notifications from iPhone" menu that gives you several options. These include options to enable or disable sounds for notifications from iPhone, select which specific app notifications to mirror, and turn the entire feature on and off.

Show Passwords in Menu Bar

If you want to make access to the new Passwords app a lot more convenient, go to Passwords ➝ Settings... and check the box next to "Show Passwords in Menu Bar." When you're next on a website in Safari that you have login credentials for, click the key icon in the menu bar, and you'll see the dropdown menu automatically detect which login details you're looking for, ready for you to select. This also works with other browsers that have the iCloud Passwords browser extension installed.

Highlight Text in Notes

The Notes app now supports colors for typed text, allowing for highlighting. Apple added five colors, including pink, purple, orange, mint, and blue, with the colors able to be added through the formatting interface. Simply click on the Aa button in the toolbar to get to the color options when a word or phrase is selected.

Math Notes

Apple has added a powerful new feature to your Mac's Calculator app: Math Notes. This integration between Calculator and Notes offers a versatile tool for all your calculation needs. It's particularly handy for splitting bills, calculating group expenses, or working through more complex mathematical problems.

Math Notes allows you to type equations directly into a note, with automatic solving when you add an equals sign. You can perform a wide range of calculations, including defining variables for more complex math. For example, if you're planning a night out, you could write "dinner = $57" and "movies = $24" in a note, then simply type "dinner + movies =" to get the total cost. To access the feature, click the calculator symbol at the bottom left of the calculator window and select Math Notes.

You're not limited to accessing Math Notes through the Calculator app – you can also use the feature directly within the Notes app using any new or existing note. In fact, you can get Math results almost anywhere in the operating system. If you type an equation into Spotlight, for example, you'll get a result, and the same goes for apps like Messages.

Private Wi-Fi Address Options

In System Settings > Wi-Fi, if you click the Details button next to the currently connected network, there's a new Private Wi-Fi address option that may be familiar to users with iOS devices. A fixed private address reduces cross-network tracking by using a unique Wi-Fi address on the network. You can make it Fixed, Rotating, or turn off the option.

Record and Transcribe Voice Notes

Apple has made a significant enhancement to the Notes app, introducing a built-in audio recording feature that streamlines the process of capturing and transcribing voice notes. The new audio recording tool in Notes offers more than just simple voice capture. As users record, the app automatically generates a real-time transcript, making it easier to review and search through recorded content.

To record a voice note, simply click the new waveform icon in the Notes toolbar. An interface will appear on the right showing the audio recording controls, as well as a speech bubble icon that you can use to view the transcript. When you've finished your recording, it will be saved in the note along with the accompanying transcription.

Window Title Bar Double-Click Options

In System Settings > Desktop & Dock, there's a new option to change the behavior of a window when you double-click its title bar. In Sonoma, the default behavior is to zoom the window, but in Sequoia you can change "Double-click a window's title bar to" Fill, Zoom, Minimize, or Do Nothing.

Here’s how you can turn off the auto-typing of periods after hitting space twice.

• Go to the  Apple menu and choose "System Settings"
• Scroll down in the list and choose "Keyboard"
• Look for the Text Input section for "Input Sources", and click the "Edit" button next to that
• Locate the switch for "Add period with double-space" and toggle that off
• Click "Done"

Now when you hit the space bar twice, the Mac will no longer automatically type a period.

• Open a Copy of a File by Default

Stationery Pad is a handy way to nix a step in your workflow if you regularly use document templates on your Mac. The long-standing Finder feature essentially tells a file's parent application to open a copy of it by default, ensuring that the original file remains unedited. Almost any file type can be defined as a template with Stationery Pad – it could be used to streamline common Photoshop jobs, create skeleton HTML/CSS files, or help with Word document invoicing.

To take advantage of it, right-click (Ctrl-click) the file that you want to use as a template, select Get Info, then check the Stationery Pad checkbox under the General section. Lastly, click the red traffic light button to close the Get Info window. Next time you double-click the template file, Finder will automatically create and open a copy of it, leaving the original untouched.

• Access More Preview File Format Options

When you come to save or export a file in Preview, Option-click the Format dropdown to get access to several additional file types.

• Add App/File/Folder Shortcuts to Finder's Toolbar

Here's how to add convenient app, file, and folder shortcuts to the toolbar of Finder windows: Simply begin to drag the item within the Finder window, then hold down the Command (⌘) key and drop it onto an available space in the toolbar.

What causes the "macOS could not be installed on your computer" error? Several issues could cause the problem. However, the error screen should give you some idea of what's gone amiss. Here are some messages you might see underneath the warning:

• The path /System/Installation/Packages/OSInstall.mpkg appears to be missing or damaged
• An error occurred installing macOS
• Unable to unmount volume for repair
• Storage system verify or repair failed
• An error occurred while verifying firmware

Some of these offer more information than others, but they point to different stages of the installation that failed. The following steps and fixes should sort out any of the problems mentioned above.

Fixing this error may require some patience. It's best to start with the simple fixes, which often solve the problem, but if they don't, you have other options. Here are the approaches to try.

1. Restart and try the installation again. This may seem counterintuitive to redo the thing that didn't work, but sometimes a restart is all your Mac needs to sort itself out.

2. Check the Date & Time setting. If the displayed date and time don't match reality, this could be the problem. Restart your Mac again if necessary, then go to System Settings > Date & Time and enable "Set time and date automatically" setting. After this, try the installation again to see if it works.

3. Free up space. In some cases, macOS fails to install because there isn't enough room on the hard drive. To see how much is available, click the Apple logo and select About This Mac, click More Info, scroll down and click Storage Settings. You'll see a breakdown of what's living on your computer. If the available space seems low, move some nonessential files off temporarily to see if that lets the installation proceed.

4. Reset the NVRAM (https://support.apple.com/en-gb/HT204063). This tiny chunk of memory stores basic information such as the time, monitor resolution, and which disk to start up from. You may need to go back into System Settings to switch any settings this changed, but you can try the installation again before that to make sure the problem is resolved.

5. Restore from a backup. If you use Time Machine to regularly back up your Mac, you can go back to an earlier state using Recovery Mode to see if it's more compatible with the installer.

6. Run Disk First Aid (launch Disk Utility located in /Applications/Utilities). This may help if you're getting the "Unable to mount volume" error. First Aid checks the internal hard drive and makes any fixes it can. It may even be able to mount the volume after it's done. Then you can retry the installation.

If none of the above worked, it may be time to turn your computer over to the professionals.