Onboard battery management device
A battery management device is provided for accurately measuring in a simple manner the internal resistance (reciprocal of conductance) of a battery that serves as the determination reference of the deterioration level of a battery without the application of an AC voltage to the battery while the battery remains onboard, and determining and displaying the deterioration level of the onboard battery. The onboard battery management device has sensors 2 and 3 for measuring terminal voltage and current of an onboard battery 1 ; a computation processor 6 for determining the deterioration level of a battery (as well as for calculating and determining the internal resistance on the basis of the measured value); and a display unit 7 of the battery state, wherein the internal resistance is determined based on an AC voltage component and an AC electric current component that are calculated by performing differential processing or subtractive processing on the voltage value and electric current value of the onboard battery during engine operation measured without the application of an AC signal from a sensor terminal; and the DC component, the low-frequency component, and the high-frequency component are removed using a filter circuit to determine the deterioration level.
1. An onboard battery management device for managing the deterioration level of an onboard battery during engine operation, the device comprising:
sensors for measuring terminal voltage and terminal current of an onboard battery;
a computation processor for calculating and determining internal resistance on the basis of said measured value and determining the deterioration level of a battery; and
a display unit of the battery state provided in a viewable location from the driver's seat, wherein
the internal resistance is determined based on an AC voltage component and an AC electric current component that are calculated by performing differential processing and subtractive processing on the voltage value and electric current value of the onboard battery during engine operation measured by sampling several times per second to several thousand times per second without the application of an AC signal from a sensor terminal during engine operation; and
the internal resistance is converter to static resistance value using a conversation formula established in advance based on data, wherein the static resistance value is battery resistance value prior to engine start up; and calculating cold cranking amperage from the static resistance value, and the deterioration level of the battery is determined based on the cold cranking amperage.
2. An onboard battery management device for managing the deterioration level of an onboard battery during engine operation, the device comprising:
sensors for measuring terminal voltage and terminal current of an onboard battery;
a computation processor for calculating and determining internal resistance on the basis of said measured value and determining the deterioration level of a battery; and
a display unit of the battery state provided in a viewable location from the driver's seat, wherein
the internal resistance is determined based on an AC voltage component and an AC electric current component that are specified by passing a voltage value and electric current value of the onboard battery at the time of engine startup through a filter circuit to remove a low frequency component and a high frequency component without the application of an AC signal from a sensor terminal during engine operation; and
the internal resistance is converter to static resistance value using a conversation formula established in advance based on data, wherein the static resistance value is battery resistance value prior to engine start up; and calculating cold cranking amperage from the static resistance value, and the deterioration level of the battery is determined based on the cold cranking amperage.
3. The onboard battery management device according to claim 1 , wherein differential processing or subtractive processing is performed while the voltage value and the electric current value of the onboard battery are measured during engine operation, a low frequency component at a prescribed level or lower is removed, and a high frequency component at a prescribed level or higher is removed by smoothing to determine the internal resistance based on a specified AC voltage component and an AC electric current component.
4. The onboard battery management device according to claim 2 , wherein the voltage value and the electric current value of the onboard battery are measured during engine operation while being passed through a band pass filter circuit or a high-pass filter circuit, whereby a DC component and a low frequency component of several hertz or lower are removed, and a high frequency component at a prescribed level or higher is removed by a low-pass filter circuit to determine the internal resistance on the basis of a specified AC voltage component and AC electric current component.
5. An onboard battery management device for managing the deterioration level of an onboard battery during engine operation, the device comprising:
sensors for measuring terminal voltage and terminal current of an onboard battery;
a computation processor for calculating internal resistance on the basis of said measured value, and determining the deterioration level of a battery; and
a display unit of the battery state provided in a viewable location from the driver's seat, wherein
the internal resistance is converter to static resistance value using a conversation formula established in advance based on data, wherein the static resistance value is battery resistance value prior to engine start up; and calculating cold cranking amperage from the static resistance value, and the deterioration level of the battery is determined based on the cold cranking amperage.
6. The onboard battery management device according to any of claims 1 through 5 , comprising temperature sensors, wherein the charging state of the battery during engine operation is determined by the generated voltage of the temperature-corrected battery, and an onboard battery charging state display function for displaying the charging state is provided.