includes an interface 61 to central processing unit 7 and utilizes console 10 as the means for providing operator control of the audio stereo sound system 60 in accordance with still yet another embodiment the present invention provides a dual function computer system that attaches to a vehicle 39 s wiring harness at a point that is local to the location of the vehicle 39 s operator but remote from the location of the battery and includes facilities added local to the vehicle 39 s battery that provide battery temperature information in addition to processing battery information this embodiment includes a theft deterrent system fig6 is a block diagram illustrating a dual function environment computer system 1 e is a dual function computer system it gathers analyzes and displays battery information in the same manner as computer system 1 b fig3 central processing unit 1 e also includes a theft deterrent system 70 that includes an interface 71 to central processing unit 7 and utilizes console 10 as the means for providing operator control of the theft deterrent system 70 included in the theft deterrent system 70 is a vibration sensor not shown an audible alarm not shown and connection 73 that controls kill switch 72 which in turn can render starter motor 74 inoperable by turning.