The latest revision (V2) of the micro:bit features a handy on/off/sleep mode to help conserve energy when the device is not in use. You can enter this mode by pressing and holding the power/reset button on the back of the micro:bit.
Sleep
When a V2.x micro:bit is powered by USB, press and hold the power/reset button for 5 seconds to enter sleep mode.
The micro:bit power LED will dim from bright red to off. It will then flash on and off, indicating that it is still connected to the power source. Your program will stop running, and the display will be off.
Press the power/reset button to wake up the micro:bit from sleep mode, or unplug and replug in the USB power cable to wake the micro:bit. Your program will restart.
Power off
When a V2.x micro:bit is powered by a battery pack attached via the on-board JST connector, press and hold power/reset for 5 seconds to power off the micro:bit.
The micro:bit power LED will dim from bright red to off. If you continue to keep the battery pack connected to the micro:bit, it will remain off until you press the power/reset button again to wake up the micro:bit.
Power off for all versions of micro:bit
Disconnecting the USB and battery power supply will always power off the micro:bit.
Wake
When a V2.x micro:bit is in sleep/power-off mode, pressing the power/reset button again will wake up the micro:bit, and your program will restart.
Removing and replugging in the USB power cable will also wake the micro:bit and restart your program.
Troubleshooting
If you find that the micro:bit does not enter low power mode when you hold down the power/reset button, please try transferring a new program from either makecode.microbit.org or python.microbit.org, which contains the latest power management software.
Further information
For technical details on how the micro:bit V2 power modes function, refer to our developer documentation on power management.
Keywords: power saving, switch off, power down, conserve energy, battery