how to use battery power on the nrf52840 dk

[chunjing]

It looks like the DK comes with a coin cell type battery and there seems to be a tab that can be pulled off to activate. Can someone explain how to switch into battery mode  without any other power source?

[awneil]

Did you check User Guide ?

https://infocenter.nordicsemi.com/topic/ug_nrf52840_dk/UG/dk/hw_power_supply.html