APPARATUS AND METHOD FOR DETECTING A BATTERY DISCHARGING CAUSE FOR A VEHICLE

An apparatus for detecting a battery discharge cause for a vehicle includes a communicator connected to and configured to communicate with a plurality of controllers, and a monitor configured to monitor a communication state of the controllers to detect a battery discharge cause through the communicator. The monitor monitors the communication state of the controllers to check whether a controller in a communication-enabled state is present when the plurality of controllers is in a state of always-on power (power B+). The monitor checks whether the controller is maintained in the communication-enabled state until a preset amount of time elapses when a controller in a communication-enabled state is present. The monitor detects a communication non-sleep controller based on the controller maintained in the communication-enabled state until the preset amount of time elapses.