RTC Backup Battery
Lithium primary battery to back up the Real Time Clock
The below listed ODROID boards has RTC circuit. You need to just connect this backup battery to keep the time when your ODROID is offline. This battery can keep the RTC running up to 3 years without external power supply.
The list of the board that RTC circuit implement.
Coin Cell : CR2032 3Volt/220mAH
Wire : 70mm
Connector : Molex 51021-0200 compatible (1.25mm pitch)
*Cable connection. Note that the red wire is Positive pole and the black wire is Negative pole.