Sanyo Electric Co., Ltd.

Jyunya Yano

Kimihiko Furukawa

Kuniho Tanaka

The car battery system of the present invention is provided with a battery blockthat retains a plurality of battery cellsin a stacked configuration and has a terminal planeA, which is coincident with terminal surfacesA established by positive and negative battery cellelectrode terminals; and with a battery state detection circuitthat connects with the electrode terminalsof each battery cell. The battery system is provided with a circuit boardwith surface-mounted electronic componentsthat implement the battery state detection circuit. The circuit boardis a single-sided board with electronic componentsmounted on only one side, and the circuit boardis attached to the battery blockopposite the terminal planeA with the side having no electronic componentsfacing the battery block. The positive and negative electrode terminalsof each battery cellare connected with the circuit boardfor connection to the battery state detection circuit

Car battery system

A car battery system includes a plurality of battery cells, each battery cell having a positive electrode terminal and a negative electrode terminal, a battery block that retains the plurality of battery cells in a stacked configuration and has a terminal surface that is formed by battery cell terminal surfaces established by the positive and negative electrode terminals, and a battery state detection circuit that is connected to the electrode terminals of each battery cell to detect the condition of each battery cell. The positive and negative electrode terminals of each battery cell are connected to a circuit board and to the battery state detection circuit. The circuit board is connected to the positive and negative electrode terminals of each battery cell via voltage detection lines, and the voltage detection lines are connected to the same locations on the electrode terminals of each battery cell.

The voltage detection circuitis provided with an isolation transformerhaving its primary side connected to batteryconnection nodesa switching deviceconnected to the primary side of the isolation transformeran isolated input circuitthat switches the switching deviceON and OFF, and a secondary voltage detection sectionthat detects output voltage from the secondary side of the isolation transformerIn the voltage detection circuitthe series input circuitof the isolation transformerprimary side and the switching deviceare connected to batterymeasurement nodes, the switching deviceis switched ON and OFF with a given periodicity by the isolated input circuitand the output voltage from the secondary side of the isolation transformeris detected by the secondary voltage detection sectionto determine the voltage across the measurement nodes.

Car power source apparatus

A leakage detection circuit for an electric vehicle includes a battery pack, first and second leakage detection switches, a controller, a leakage detection resistor, a voltage detector, and a calculator. The first and second leakage detection switches are connected to the high and low voltage sides of the battery pack, respectively. The battery pack includes a plurality of batteries that are connected in series. The midpoint of the leakage detection resistor is connected to the ground via the first and second leakage detection switches. The controller alternately turns the first and second leakage detection switches ON. Thus, the voltage detector detects leakage voltage values that are generated in the leakage detection resistor. The controller turns the first and second leakage detection switches ON and OFF, respectively, to detect a first leakage voltage value of the leakage voltage values. On the other hand, the controller turning the first and second leakage detection switches OFF and ON, respectively, to detect a second leakage voltage value of the leakage voltage values. Consequently, the calculator detects leakage based on the first and second leakage voltage values.

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Kasai, Japan

Jyunya Yano