Amphetamine: Keep your MacBook awake in the clamshell mode without a power adapter An essential utility for your MacBook by: Yash Wate - Last updated on: December 19th, 2020 Key Takeaways Macbooks don’t offer the ability to run the laptop in the clamshell mode without requiring the power adapter. Instead, it requires you to have your MacBook connected to a power source to prevent it from going into sleep mode when you close the lid. Amphetamine is a free keep-awake utility for MacBooks, which keeps them awake in clamshell mode even without external power. For more such utilities, check out our Downloads hub.