JP3338264B2 - Battery evaluation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery evaluation apparatus for automatically charging and discharging a battery in a battery evaluation test.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing a configuration of a conventional battery evaluation device. In this figure, reference numeral 1 denotes a DC power supply connected in parallel to the battery 2 and outputs a charging current Ic to the battery 2 during charging. The battery 2 is configured by connecting ten single cells (nominal voltage: 1.2 V) in series, and the nominal voltage is 12 V.

[0003] Reference numeral 3 denotes a diode. The anode A is connected to the positive terminal of the DC power supply 1, and the cathode K is connected to the positive terminal of the battery 2. Reference numeral 4 denotes an electronic load device which is connected in parallel to the battery 2 and is used as a load of the battery 2 during discharging. The electronic load device 4 can be used as a load having various characteristics such as a constant current load and a constant power load.

In such a configuration, a constant charging current Ic is supplied from the DC power supply 1 to the diode 3 during the charging test.
Is supplied to the battery 2 to charge the battery 2. When the terminal voltage Vb of the battery 2 reaches a certain voltage, the output voltage of the DC power supply 1 becomes zero,
Charging ends. Thereafter, after a certain pause time has elapsed, the electronic load device 4 is set to, for example, a constant current load, and a discharge test is performed. Then, the terminal voltage Vb of the battery 2
Is reduced to a certain value, the discharge test ends. In the above test process, the battery 2 is evaluated based on the time required for charging and the time required for discharging. Note that the above process is an example, and various tests such as a test with a load that fluctuates every second are performed in the battery test.

[0005]

In the above-described conventional battery evaluation device, the diode 3 is inserted for the following purpose. That is, during the discharge test,
Even if the output voltage of the DC power supply 1 is set to zero, if the diode 3 is not provided, a current flows from the battery 2 to the DC power supply 1, so that the output current of the battery 2 is set in the electronic load 4. It will be different from the current, making accurate testing impossible. However, when the diode 3 is inserted, power loss occurs due to the voltage drop, and the output voltage of the DC power supply 1 and the terminal voltage Vb of the battery 2 are different from each other. Is quite large,
A diode 3 having a large current capacity is required, which causes a problem that the shape becomes large and the price becomes expensive. On the other hand, it is possible to insert a relay contact in place of the diode 3, but in this case also, a contact having a large current capacity is required, which is not preferable in terms of shape and cost. Therefore, an object of the present invention is to provide a battery evaluation device capable of reducing the current flowing into a DC power supply device to zero without using a diode or a relay contact.

[0006]

According to a first aspect of the present invention, there is provided a DC power supply for supplying a charging current to a battery during a battery charging test, and a load through which a discharging current flows from the battery during a discharging test of the battery. Means, current detection means for detecting a current flowing from the battery to the DC power supply during the discharge test, and an output of the DC power supply such that the current detected by the current detection means becomes zero during the discharge test. A battery evaluation device comprising: a first control unit that controls a voltage.

According to a second aspect of the present invention, in the first aspect of the invention, input means for inputting measurement conditions such as a charging current in the charging test and measurement conditions such as a discharging current in the discharging test, A second control means for controlling the DC power supply and the load means in accordance with the requirements input by the input means is provided.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a battery evaluation device according to one embodiment of the present invention. In this figure, parts corresponding to the respective parts in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. In this figure, reference numeral 5 denotes a personal computer (hereinafter, referred to as a personal computer), which comprises a computer main body, a display, and a keyboard. Then, based on a test procedure previously input by a tester, the DC power supply 1 and the electronic load 4
Control. The operation of the personal computer 5 will be described later in detail.

Reference numeral 7 denotes a battery voltmeter for measuring the terminal voltage Vb of the battery 2, and its output is supplied to the personal computer 5 via the interface 11. Reference numeral 8 denotes a temperature sensor which measures the temperature of each part of the battery 2 and outputs the measured temperature to the personal computer 5 via the interface 11.

Reference numeral 9 denotes a pressure sensor for measuring the internal pressure of each cell of the battery 2, and outputs a pressure detection result to the personal computer 5 through the interface 11. Reference numeral 10 denotes a cell voltmeter that measures the cell voltage of each cell of the battery 2, and outputs a measurement result to the personal computer 5 via the interface 11.

Reference numeral 12 denotes a current detector, which is composed of a shunt resistor having a resistance value R (several mΩ).
It is inserted between the negative terminal of the DC power supply 1 . When currents (charge current, discharge current) flow through the current detector 12, the voltage drop Vi generated at this time is changed by the A / D converter 13
Is converted into a digital signal and output to the personal computer 5.

Next, the operation of the above-described device will be described. First, the tester operates the keyboard of the personal computer 5 to set each measurement condition of the battery test. For example, when performing a constant current charge-constant current discharge test, a charge current, a charge end voltage of the battery 2, a pause time after charge, a discharge current, and a discharge end voltage of the battery 2 are sequentially input.

Next, when the tester performs a test start operation on the personal computer 5, the personal computer 5 first proceeds to a charging process to turn off the electronic load device 4 and, at the same time, to the DC power supply device 1. The current value set in the process is output. Thereafter, the set constant charging current Ic is supplied from the DC power supply 1 to the battery 2, and the battery 2 is charged at a constant current.

The personal computer 5 outputs each output of the battery voltmeter 7, the temperature sensor 8, the pressure sensor 9, and the cell voltmeter 10 via the interface 11 every time a predetermined time elapses during charging. Read and A / D
The output of the converter 13 is read. Then, whether or not the output of the temperature sensor 8 is within a preset range, whether or not the output of the pressure sensor 9 is within a preset range, and the variation between the cell voltages is within a certain range. Check to see if it is. If any one of the items does not satisfy the condition, it is determined that an abnormality has occurred, the battery test is stopped, and an alarm is sounded. PC 5
Checks whether the output of the A / D converter 13 has reached the set current.

Further, the personal computer 5 checks whether or not the output of the battery voltmeter 7 has reached the charge termination voltage set by the tester. When the charging end voltage is reached, the time required for charging is stored in an internal memory, the output voltage Vo of the DC power supply 1 is set to zero, and thereafter, the measurement of the pause time set by the tester is performed. Do.

Also, during this pause time, the personal computer 5 performs a measure to prevent the personal computer 5 from flowing into the DC power supply 1. That is, first, when the output voltage Vo of the DC power supply 1 is set to zero, the current flowing through the current detector 12 (that is, the current flowing into the DC power supply 1) is converted by the A / D converter 1
Check based on the output of 3. If the current is not zero, the output voltage Vo of the DC power supply 1 is slightly increased, and the current of the current detector 12 is checked again. Hereinafter, this process is performed until the output of the current detector 12 becomes zero. Then, when the current flowing through the current detector 12 becomes zero, the output of the DC power supply device 1 is held in that state even during the discharge test thereafter.

Next, when the pause time set by the tester elapses, the personal computer 5 outputs the load current value set by the tester to the electronic load device 4. This allows
The electronic load device 4 becomes a constant current load, and thereafter, the battery 2
Supplies a constant discharge current Id to the electronic load device 4.

While the discharge test is being performed, the outputs of the A / D converter 13, the battery voltmeter 7, the temperature sensor 8, the pressure sensor 9, and the cell voltmeter 10 are checked. Is checked. And
When the output of the battery voltmeter 7 reaches the discharge end voltage, the personal computer 5 turns off the electronic load device 4, displays the time required for charging and the time required for discharging on the display, respectively, and ends the one-cycle test. I do.

[0019]

As described above, according to the present invention,
The current flowing into the DC power supply can be reduced to zero without using a diode or a relay contact.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a battery evaluation device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional battery evaluation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 DC power supply 2 Battery 4 Electronic load 5 Personal computer 12 Current detector Ic Charge current Id Discharge current

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-203876 (JP, A) JP-A-6-90530 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 10/42-10/48 H02J 7/00-7/12 G01R 31/36

Claims (2)

(57) [Claims] A DC power supply for supplying a charging current to the battery during a charging test of the battery; a load means through which a discharging current flows from the battery during a discharging test of the battery; Current detection means for detecting a current flowing into the DC power supply; and first control means for controlling an output voltage of the DC power supply so that a current detected by the current detection means becomes zero during the discharge test. A battery evaluation device. 2. Input means for inputting measurement conditions such as charging current in the charging test and measurement conditions such as discharging current in the discharging test; and the DC power supply and the load means according to the measurement conditions input by the input means. 2. The battery evaluation device according to claim 1, further comprising: a second control unit configured to control the battery evaluation device. 3.