Abstract: A vehicle control unit estimates a temperature of the vehicle's battery including the temperature of each of the battery's plurality of cells. The control unit includes a memory unit having stored therein heat transfer coefficients of three types. The first type is representative of heat transfer between the cells of the battery; the second type is representative of heat transfer between the surrounding air and the middle cells of the battery; and the third type is representative of heat transfer between the surrounding air and the end cells of the battery. A microprocessor retrieves the heat transfer coefficients from the memory unit and determines individual cell temperatures of the battery based on the heat transfer coefficients, temperature of the ambient air, and the drive state of the vehicle.

Abstract: An arrangement for mounting a battery monitoring circuit on the cover of the battery and for connecting the terminal ends of first and second lead wires of a battery monitoring circuit to the positive and negative terminals of the battery, the arrangement including a cavity formed in the battery cover for mounting the battery monitoring circuit, first and second battery terminal bushings which are molded integrally with the cover and are adapted to be mounted on and connected to the positive and negative battery terminals when the battery cover is installed on the battery, each of the battery terminal bushings including a pad having an upwardly directed mounting post that is adapted to receive and secure the terminal end of one of the lead wires of the battery monitoring circuit, the battery cover having first and second lead wire slots in its surface which extend from the cavity in which the battery monitoring circuit is mounted, to the locations of the battery terminal bushings for directing the lead wires

Abstract: A state of charge indicator monitors a voltage produced by a depletable energy source and provides an indication when the state of charge of the depletable energy source falls below a predetermined threshold. The state of charge indicator includes an input circuit for sensing the voltage and producing a plurality of tap voltages. The state of charge indicator further includes a monitor circuit for comparing each tap voltage with a corresponding threshold voltage and producing a result for each tap voltage falling below its corresponding threshold. The state of charge indicator still further includes a storage device for storing each result and producing an accumulated status and an output circuit for producing the indication when the accumulated status exceeds an accumulated status threshold.

Abstract: A battery thermal control system and method is provided which selectively heats or cools a storage battery in accordance with the battery temperature and state of charge. The thermal control system includes a battery housing having an internal airspace between the battery and the housing which extends between two openings in the battery housing, a reversible fan configured to generate an airstream along the airspace, a temperature sensor mounted to detect the temperature of the battery, and a control circuit for monitoring battery temperature and voltage and for controlling the operation of the fan. Battery state of charge is approximated by measuring battery voltage and monitored to prevent excessive battery discharge by the thermal control system. When the battery voltage exceeds a predetermined voltage and the battery temperature is outside of a predetermined range of suitable operating and storage temperatures, the thermal control system operates the fan to heat or cool the battery, as needed.

Abstract: A voltage monitor and method enables the monitoring of a DC input voltage. The input voltage is continuously scanned and compared to a predetermined threshold. The result of the comparison is periodically stored in a shift register along with previous scan results. When a predetermined number of stored scan results indicate an out of range input voltage, a digital output changes state to provide indication of the abnormal condition.