User`s manual

BDM-610000082 Rev A Chapter 3: Connecting the cpuModule 31
Battery
Pin 9 of the Utility Port 2.0 connector is the connection for an external backup battery. This battery is used by
the cpuModule when system power is removed in order to preserve the date and time of the real time clock.
Connecting a battery is only required to maintain time when power is completely removed from the cpuModule.
A battery is not required for board operation.
WARNING The optional RTC battery input connector (CN13) should be left unconnected if the
multi-function connector (CN5) has a battery connected to pin 9.