How does the automatic battery cut off logic prevent complete battery discharge on ground in the A320?
According to this page: http://theflyingengineer.com/projects/airbus-tech/electrical/

A Battery Automatic cut-off logic prevents the batteries from discharging completely when the aircraft is on the groung [sic] (Parking).
Automatic battery contactors open when :

The a/c is on the gorund [sic].
The BAT P/b s/w’s are at AUTO
The main power supply (EXT PWR+GEN) is cut off
Battery Voltage is low.


Nothing should automatically disconnect the batteries from the corresponding HOT BUS, so if something is left on the HOT BUS it would continue to drain the battery.