macOS Catalina - External Hard Drive not sleeping when lid closed and laptop sleeping So I'm trying to figure out why my external hard drive remains on (light displaying) when the laptop is sleeping.

Details:


macos 10.15.3
macbook pro 


energy saver


disabled > Enable Power Nap while on battery power disabled in battery and power adapter
enabled > Put hard disks to sleep when possible in battery and power adapter
The LED on your USB external drive probably just indicates that it is connected to power.

The MacBook Pro provides connected USB devices with at least 0.50 watts of power (according to the USB power specification and Apple technote HT204377) even when the laptop has been put to sleep. This low level of power is particularly helpful for input devices like keyboards and mice, because it ensures they have enough power to register activity that can be used to wake the system.

If you want the drive LED to turn off, you can either unplug it from the laptop or you can shut down the laptop completely.