Safety device to prevent excessive battery drain
OwnerJeffrey M. Sloaninventor
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Abstract
A safety device is wired in series with selected accessories in a wiring circuit for a vehicle. The safety device of the present invention determines the state of charge of the battery as a function of the rate of discharge of the battery. When the state of charge falls below preset values, the device activates a switch which disconnects the battery from the vehicle wiring circuit in order to save sufficient energy for engine ignition. In another embodiment, a programmed microprocessor activates electronic switches to sequentially disconnect banks of accessories from the battery.
Claims26
For use in conjunction with a vehicle having a battery, an ignition system, and at least one electrically powered accessory connected to the battery, a device for electrically disconnecting the battery from the accessory whenever the battery energy falls below a predetermined value comprising:
- a normally closed switch connected in series between the battery and the accessory, and
- means for opening said switch comprising:
- means for sensing a battery characteristic indicative of battery drain and for generating an output signal whenever an energy capacity of said battery falls below said predetermined value,
- timing means responsive to said sensing means output signal for generating a timing output signal a predetermined time period after said sensing means output signal, and
- means responsive to said timing means output signal for opening said switch,
- wherein said sensing means comprises means for determining the rate of discharge of the battery and for adjusting a threshold level at which said timing means is activated as a function of the rate of discharge of the battery.
For use in conjunction with a vehicle having a battery, an ignition system, and at least one electrically powered accessory connected to the battery, a device for electrically disconnecting the battery from the accessory whenever the battery energy falls below a predetermined value comprising:
- a normally closed switch connected in series between the battery and the accessory, and
- means for opening said switch comprising:
- means for sensing a battery characteristic indicative of battery drain and for generating an output signal whenever an energy capacity of said battery falls below said predetermined value,
- timing means responsive to said sensing means output signal for generating a timing output signal a predetermined time period after said sensing means output signal, and
- means responsive to said timing means output signal for opening said switch,
- wherein said sensing means comprises a first and second comparator, said first comparator generating a first output signal to said timer means which resets and energizes said timing means when the battery voltage falls below a first voltage level, said second comparator generating an output signal which activates and initiates the beginning of said predetermined time period when the battery voltage falls below a second voltage level, said first voltage level being greater than said second voltage level.
Dependencies are inferred from the claim text.