Battery saving mode
The display of Polar FA20 Activity Computer automatically switches to battery saving mode if it hasn't detected any movement within the last hour. In battery saving mode the display is blank. You can turn the FA20 back on by pressing any button for one second.
The FA20 is in battery saving mode when it is dispatched from the factory.
If you cannot activate the FA20 by pressing a button, its battery may be empty. Low battery indicator is displayed when there is 10 - 15% of the battery capacity remaining. For more information see the FA20 user manual.