System and method for avoiding depleted battery in a parked vehicle

A vehicle electrical system has a battery monitor configured to measure battery current flowing from a vehicle battery and a power management controller receiving a measured battery current value from the battery monitor. A plurality of controller modules receives the current flowing from the vehicle battery, each controller module being coupled to the power management controller to exchange communication signals. The power management controller detects a key-off state wherein the plurality of controller modules are each configured to invoke a respective reduced-power mode. When the battery load exceeds a sleep threshold during the key-off state then the power management controller resets at least one of the modules to re-invoke the respective reduced-power mode. The resetting can involve cycling a status of an ignition signal from ON to OFF.