Abstract: A battery control and alarm system for a vehicle electrical system including a first, normally open, solenoid-actuated switch connected in series with the main battery cable; a second, magnetically actuated reed switch proximate the vehicle ignition switch and connected to the battery; and circuitry to close the first switch when the second switch is closed and for a limited delay period after the second switch is opened. In a preferred embodiment, the system includes a third, magnetically actuated reed switch and circuitry to both sound the vehicle horn and close the first switch when the third switch is closed.