This net connects to the pin 'VBACKUP' of the power management chip TPS65022.
It exists to source power from an off-board backup battery. V_BACKUP_BATT is located on the 24-pin flex ribbon (Verdex only) connector
If your application needs a backup battery, connect a 3V Li-Ion cell directly to V_BACKUP_BATT and GND and remove R9 (0 Ohm resistor to ground).
Use a boost converter (ex. TPS61070) if you use a single NiMH battery
In systems where no backup battery is used, this net is connected to GROUND.
On the verdex, this is done with R9 (0 Ohm resistor), which is populated by default on our website-sale boards.
Powering Gumstix from batteries