Abstract: A non-isolated type voltage sensor is provided between a battery of less than 60 V and a circuit having a resistor, an end of which is connected to a wire harness while another end is connected to a reference power supply. The non-isolated type voltage sensor includes voltage dividing circuits, which include plural resistors connected in series such that those resistors are connected to the battery in parallel so as to obtain a voltage proportional to a terminal voltage of the battery and less than the reference voltage at a desired voltage dividing point of the plural resistors, a voltage follower, which receives an input of a voltage from the voltage dividing point of the voltage dividing circuit, and a voltage-current conversion circuit including a FET so as to supply a current proportional to a low impedance output voltage obtained through the voltage follower to the ground through a resistor.

Abstract: A battery charge control device is capable of detecting a gassing state in a battery without using a temperature sensor. Under condition of charging the battery 5 with a charging current, when a terminal voltage Vi of the battery 5 monitored by the device exceeds a threshold value, a temporary-gassing detecting unit 23 informs a voltage regulation calculating unit 24 that the battery 5 is in course of reaching its gassing state. The voltage regulation calculating unit 24 calculates a changing rate of terminal voltage Vi of the battery 5 while it is in course of reaching the gassing state. When the calculated changing rate exceeds a preset decision value, a gassing detecting unit 25 judges that the battery 5 has just reached the gassing state. A decision value renewing unit 27 changes the decision value corresponding to the charging current.

Abstract: The temperature of a battery is detected by a temperature sensor, and a gassing voltage based on the temperature is determined by a gassing detection processing section at all times, and even during traveling, a full charge capacity calculation processing section estimates a full charge capacity on the axis of the full charge capacity from when the gassing occurred, from the remaining capacity at the time of gassing and a chargeable capacity.

Abstract: A junction box includes a battery controller. The battery controller includes a high voltage battery remaining capacity measuring portion, a low voltage battery remaining capacity measuring portion and a charging instruction portion. The high voltage battery remaining capacity measuring portion collects predetermined plural pairs of voltage value and current value, obtains an approximate straight line on current-voltage coordinates based on the predetermined plural pairs of the data according to least square method, and then obtains a voltage value based on the approximate straight line and a predetermined current value so as top estimate a remaining capacity of the high voltage battery.

Abstract: A junction box provided between a high voltage battery and a load supplies a high voltage to the load, generates a predetermined low voltage from that high voltage and supplies the low voltage to a low voltage battery and load. If over-current flows through the high voltage system circuit or low voltage system circuit, the junction box shuts off an input of the high voltage. The junction box is provided with an over-voltage countermeasure circuit which even if an over-voltage exceeding 36 V is supplied from the high voltage battery, suppresses it to a predetermined high voltage and outputs. Further, the junction box includes a controller for estimating a remaining capacity of each of the high voltage battery and low voltage battery by detecting respective voltages and currents of the high voltage system circuit and low voltage system circuit.

Abstract: A method and apparatus capable of detecting a considerably high voltage of a power supply while preventing an increase in the size and cost of circuitry, an increase in the amount of heat being generated, and a reduction in the detection accuracy of the circuitry. The voltage of a power supply to be detected is divided by way of a voltage-dividing resistor array. An voltage-to-current converter converts a potential difference appearing across the second voltage-dividing resistor in the array into a primary current so as to correspond to the potential difference. The converted primary current flows through a primary winding and an energization resistor. A second magnetic flux develops in a magnetic core from a secondary current, which flows through the secondary winding from a current buffer on the basis of the voltage output from a hole element according to the primary current.