The latest revision (V2) of the micro:bit has a handy on/off/sleep mode to help conserve energy when you are not using the device. You can enter this mode by pressing and holding the power/reset button on the back on the micro:bit.
Sleep
When powered by USB, press and hold power/reset for 5 seconds to enter sleep. The micro:bit power LED will dim from bright red to off. It will then flash on/off, showing you that it is still connected to the power source. Press power/reset to wake up.
Removing the USB power cable and re-adding it will also wake the micro:bit.
Power off
When powered by battery 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. It will then remain off until you press the power/reset to wake up. Disconnecting the USB and battery power supply will also power off the micro:bit.
Inserting a USB power lead will also wake the device.
Wake
Pressing the power/reset again when in sleep/power-off mode will wake the micro:bit and your program will restart.
Removing the USB power cable and re-adding it will also wake the micro:bit.
Troubleshooting
If you find that the micro:bit does not enter a low power mode when you hold down the button, please try flashing a new program from the makecode.microbit.org or python.microbit.org editor which contains the latest power management software.
Further information
For technical details on how this works, see our developer documentation on power management
Keywords: power saving, switch off, power down, conserve energy, battery