Turn on HoloLens
Press the power button for 1 second to turn on your HoloLens when it's off or in standby. If it doesn't turn on, plug it in and charge it for at least 30 minutes.
To restart HoloLens, say "Hey Cortana, reboot the device."
Put HoloLens in standby
To put your HoloLens in standby, when it's turned on, press the power button once. The battery indicators will blink off. To wake it from standby, press the power button again.
HoloLens automatically goes into standby after 3 minutes of inactivity. Once it's in standby, it will automatically shut down after 4 hours, or after the battery level drops by 10 percent.
Shut down HoloLens
To turn off HoloLens, hold the power button down for 4 seconds. The battery indicators will go off one by one and the device will shut down.
HoloLens will shut down automatically when the battery level drops to 1 percent, even if it's plugged in. Once you've recharged the battery to 3 percent, you'll be able to turn HoloLens on again.