Although there is a workaround, which requires you to change the default properties (pmset – power management settings) of macOS to deal with this situation, we do not recommend going that route. Rather, we recommend using an alternative approach, which is to use a utility that bypasses this restriction. You can find several such utilities on the internet that enable you to use your MacBook in the clamshell mode without having it connected to power all the time. One such utility that we are checking out here is Amphetamine — a drug-like sounding app available for free on the Mac App Store, which helps you keep your MacBook awake in clamshell mode.
Clamshell mode on MacBook
Before diving straight into Amphetamine, here’s what you need to know about clamshell (closed-display) mode on MacBook.
How to use Clamshell mode on MacBook?
The default way or the Apple way of using your MacBook in clamshell mode — with external monitor and peripherals connected — is to have a power adapter always attached to the machine to serve power to the connected peripherals and prevent it from going into sleep mode.
Is Clamshell mode bad for your MacBook?
Most users follow this (Apple) approach to use their machine with an external display. However, only a very few actually realize the potential problems that it can inflict over time. You see, all rechargeable batteries have a specific charge cycle — complete charge and discharge — and every time you charge it, it counts towards the battery’s degradation, which slowly wears it down to a point where it (sometimes) stops charging at all. Linux and Windows laptops, on the other hand, intelligently detect the peripherals connected to a laptop and stay awake when the lid is closed. However, sadly, Apple lacks this ability. And therefore, it requires you to connect your machine to a power adapter to prevent it from going into sleep mode. And this is exactly where Amphetamine comes into play by making it possible for you to use your MacBook in the clamshell mode without connecting it to a power adapter. That way, you do not risk the chances of damaging your battery.
Amphetamine
Amphetamine is a free keep-awake utility for MacBooks, which keeps them awake in clamshell mode even without external power. It is available as a free app on the App Store and supports macOS X and the above versions. The app offers a bunch of different options and easy-to-configure triggers that you can configure to your preference. And the best part about it is that, despite being free, it does not have any ads, nor are there any hidden in-app purchases.
How to use Amphetamine?
First, go ahead and click this link to download Amphetamine on your MacBook.
Once the app is installed, hit Next and follow the on-screen instructions. You only need to do this once — to set the app for its initial use. And as soon as you do that, you get the Amphetamine icon in the menu bar.
Click on the Amphetamine icon, select Quick Preferences, and uncheck the box next to Allow system sleep when display is closed.
When you uncheck the box, you get a pop-up suggesting you install Amphetamine Enhancer. Although this is optional, the app says it is a fail-safe measure to ensure your MacBook performs ideally and does not run into issues.
Click on the Get Amphetamine Enhancer button in the pop-up, and you will be redirected to the app’s GitHub page, from where you can download it.
Once you download Amphetamine Enhancer, double-click on its (.dmg) file to install it on your machine.
Finally, run Amphetamine Enhancer. And from its landing page, select Closed-Display Mode Fail-Safe as the Enhancement and hit the Install button on the right window.
Now, when you close the lid and put your MacBook in clamshell mode, you should be able to use it without the need for a power adapter. To ensure that the app works and that your MacBook will not go into sleep mode when you close the lid, check the app’s icon in the menu bar to get its current status. Amphetamine has two states: session active and no session active. And, for the app to be able to serve its intended functionalities, you need it to have an active session. You can start or end a session by simply right-clicking on the app’s icon in the menu bar. Alternatively, you can also click on the icon and choose the Start New Session or End Current Session option to start or end a session, respectively. With the default menu bar icon, a horizontal split in the circle denotes no active session, whereas a vertical split implies that a session is active.
If that is all that you want out of your MacBook, you have been covered so far. However, if you are interested in checking out other features on Amphetamine, here’s a quick run-through of some of the most useful ones.
1. Start a new session using different parameters
Amphetamine gives you a few different parameters to start a new session. These parameters are called Triggers, and you can either pick the default triggers or create custom ones. For this, click the app icon in the menu bar and select Preferences. From here, select the Triggers tab and check the checkbox next to Enable Triggers. Now, hit the plus (+) button at the bottom and create a criterion-value pair. For instance, you can have the trigger set to your current Wi-Fi connection. So, whenever you are connected to that network, the session begins automatically. Alternatively, you can start a session for a specific period of time, trigger it when you have a download or an app running in the background.
2. Auto-run Amphetamine and start a session at startup
Creating triggers gives you more control over how and when you want the app to start a session. However, in case you use your MacBook in the clamshell mode most of the time, you can have the app run at startup, and subsequently, have it trigger a new session.
3. Change specific settings for session type
Amphetamine has different sets of functionalities that apply to either Non-Trigger Sessions or All Sessions. So, based on your preference, you can enable/disable these functions for the two types of sessions. Some of the functionalities you get allow you to change the behavior for the screen saver, display sleep, battery, lock screen, mouse, etc. [You can access these by clicking on the app icon and selecting Preferences.] One of the useful functionalities of the lot is related to the battery, and it gives you an option to end a session when the battery level on your MacBook reaches below 10%.
4. Hotkeys
If you prefer doing everything with your keyboard, hotkeys make it possible for you to control various functionalities on the Amphetamine app using your keyboard. For this, all you need to do is record (create) hotkeys (kind of like shortcuts) for these actions. Once done, you can then hit these hotkeys to perform actions quickly.
5. Miscellaneous
Lastly, besides those core essential features and functionalities, you also get a few trivial ones that you can change or use based on your preference. For instance, you can change the quick-start/stop option, hide/unhide the app icon from the Dock, change the menu bar app icon (and other customizations), and reset settings, among others. After having struggled for a long time, tried a bunch of different keep-awake utilities, I personally find Amphetamine to be a better option of the lot. And a big reason for that has to do with the ease of use and the plethora of options that the app offers. Needless to say, it works all the time reliably. So, if you use your MacBook with an external monitor in clamshell or closed-display mode and are looking for utilities to prevent your machine from going into sleep mode, you must definitely check out Amphetamine. Download Amphetamine
