NOVELTY - Battery operation and life is preserved during vehicle post idle shutdown, with vehicle having a delayed accessory power mode, by detecting whether the vehicle (10) has been in a post idle shutdown condition and brake pedal not pressed and ignition state unchanged; and placing the vehicle in the delayed accessory power mode after detecting that the vehicle has been in a post idle shutdown condition while the ignition switch is in the ON position.    USE - Method of preserving battery operation and life during vehicle post idle shutdown (claimed).    ADVANTAGE - The method provides an architecturally integrated passive solution of preserving battery operation and life during post vehicle idle shutdown that has the advantages of meeting rigorous automotive validation standards. The solution is also designed to be inserted into the primary power feeds without a major disruption in existing wiring harness design and manufacturing impact. Solution enhancement of network allows for provisions to provide vehicle message such as door ajar to promote lights out feature from vehicle delay accessory providing addition battery saving capability.    DETAILED DESCRIPTION - Preservation of battery operation and life during vehicle post idle shutdown, such vehicle having a delayed accessory power mode operative when an ignition state of the vehicle is in a non-engine running condition while an ignition switch of the vehicle is in the ON position to supply power to accessories in the vehicle from the battery (14), comprises detecting whether the vehicle (10) has been in a post idle shutdown condition and brake pedal not pressed and ignition state unchanged; and placing the vehicle in the delayed accessory power mode after detecting that the vehicle has been in a post idle shutdown condition while the ignition switch is in an ON position. After placing the vehicle in the delayed accessory power mode after detecting that the vehicle has been in a post idle shutdown condition, the mode is returned to a previous mode in response to a vehicle operator touching a brake pedal state or changing vehicle ignition state. The detecting step uses network message information indicating vehicle speed, brake pedal state, and vehicle ignition state input. The information includes door ajar signals.    DESCRIPTION OF DRAWING(S) - The drawing shows a diagram of a vehicle having apparatus for preserving battery operation and life by interruption of vehicle power during vehicle post idle shutdown.    Vehicle (10)    Battery preserving apparatus (12)    Battery (14)    Internal combustion engine (16)    Engine status signal (27)    Relay (44)    Ignition keys (48)    Ignition switch (49)