Niko Home Control for traditional wiring - How do I know that the battery of the Zigbee® switches is empty?

When used and the battery voltage level drops below a certain threshold, a battery low notification will be visible in the Niko Home app. The notification will appear once a day.
During the pairing procedure, the feedback LED on the rear side of the Zigbee® battery powered switch will be colored red (steady or blinking) when the voltage also drops below a mimimum theshold.
Replace the battery when the switch no longer triggers stable actions.