JPH0617114U - Battery pack discharge device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an assembled battery discharging device capable of completely discharging an assembled battery without reverse charging of the unit battery. [Constitution] The battery pack 1 has a contact portion 6 connected to each unit cell 2 constituting the assembled battery 1, a voltage detection portion 7, and a control portion 5. The control unit 5 receives the detection signal a from the voltage detection unit 7 and outputs the control signal d to the contact portion 6 corresponding to the completely discharged cell 2 to short-circuit both electrodes of the cell 2. As a result, all the unit cells 2 are completely discharged without being reversely charged.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an assembled battery discharging device, and is particularly useful when applied to a case where each unit cell forming the assembled battery is completely discharged.

[0002]

[Prior art]

 FIG. 3 is a block diagram showing a configuration of an assembled battery discharging device according to a conventional technique. As shown in the figure, the conventional assembled battery discharge device includes a load device 4, a current detection unit 3, a voltage detection unit 8, and a control unit 9.

Of these, the load device 4 is connected to an assembled battery 1 configured by connecting a plurality of unit cells 2 which are secondary batteries in series to discharge the assembled battery. The current detector 3 is connected to the load device 4, detects the discharge current flowing through the load device 4, and outputs a detection signal b2. The voltage detection unit 8 detects the voltage across the battery pack 1 and outputs a detection signal a2. The control unit 9 inputs the detection signal b2 and the detection signal a2 and outputs the control signal c2 to the load device 4 in order to control the discharge current.

[0004]

[Problems to be solved by the device]

 The secondary battery needs to be completely discharged so that the voltage of the secondary battery becomes zero for refreshing (activation of the electrode plate), storage and transportation. However, when the assembled battery 1 is discharged using the above-described conventional discharge device, even if the voltage across the assembled battery 1 detected by the voltage detection unit 8 is zero, In some cases, the individual unit cells 2 forming the assembled battery 1 cannot be completely discharged.

This is because there is a variation in characteristics between individual unit cells 2, that is, a variation in discharge capacity. Therefore, a unit cell having a smaller discharge capacity than another unit cell is different from another unit cell. This is because the voltage becomes zero before that, and after that, it is reversely charged by another cell that still has voltage.

FIG. 2 is an explanatory diagram showing an example of a state in which some of the unit cells are reversed by such reverse charging. As shown in the figure, even if the voltage E0 across the battery pack 1 is zero, the individual battery cells 2 have voltages E1 to E4, and E2 and E3 are transferred by reverse charging. I'm on the pole.

[0007] Generally, the unit cell 2 is very weak in reverse charging due to its nature, and continuing reverse charging is not preferable because it causes deterioration of battery performance.

Therefore, conventionally, in order to surely perform a complete discharge, first, by using the discharge device, until the voltage of the battery pack 1 reaches a predetermined voltage (a voltage at which the reverse charge is unlikely to occur). After discharging, the assembled battery 1 must be disassembled into unit cells, and each disassembled unit cell 2 must be completely discharged by using a resistor or a short-circuit plate. It was

Further, even when the battery is completely discharged by the above method, the unit cell 2 has extremely poor characteristics as compared with other unit cells 2, that is, a unit cell having an extremely small discharge capacity. When the battery 2 is present, there is a high possibility that the voltage of the unit cell 2 becomes zero and the battery is reversely charged before the voltage of the battery pack 1 reaches the predetermined voltage due to discharge. There are also points.

The present invention has been made in view of the above-mentioned conventional art, and an object of the present invention is to provide an assembled battery discharge device capable of completely discharging the assembled battery without reverse charging of the unit cell.

[0011]

[Means for Solving the Problems]

 The configuration of the present invention to achieve the above-mentioned object is to connect a load device connected to an assembled battery constituted by connecting a plurality of unit cells, which are secondary batteries, in series, and to both electrodes of each unit cell, A contact part capable of short-circuiting between both electrodes of the unit cell, a plurality of voltage detecting units for detecting the voltage of each unit cell, and a detection signal respectively input from each of the voltage detecting units were input to completely discharge. An assembled battery discharging device, comprising: a control unit that closes a contact portion corresponding to a unit cell to short-circuit both electrodes of the unit cell.

[0012]

[Action]

 According to the present invention having the above-mentioned configuration, the voltage of each unit cell is constantly detected by the voltage detection unit during discharging of the assembled battery, and when the voltage of any of the unit cells becomes zero, the connection connected to the unit cell is detected. A control signal is output from the control section to the point section, whereby the point section is closed and the unit cell is short-circuited. After that, such short-circuiting of the unit cells is sequentially performed, and finally the voltages of all the unit cells constituting the assembled battery become zero.

[0013]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an assembled battery discharging device according to an embodiment of the present invention. As shown in the figure, the assembled battery discharge device includes a load device 4, a current detection unit 3, a contact unit 6, a voltage detection unit 7, and a control unit 5.

Of these, the contact portion 6 is connected to both poles of each unit cell 2 to short-circuit between both poles of the unit cell 2. The voltage detection unit 7 is connected to each unit cell 2 to detect the voltage of the unit cell 2 and output a detection signal a. The control unit 5 inputs the detection signal b from the current detection unit 3, outputs the control signal c to the load device 4 to control the discharge current, and inputs the detection signal a from each voltage detection unit 7. The control signal d is output to the contact portion 6 corresponding to the completely discharged unit cell 2, and the contact portion 6 is closed to short-circuit both electrodes of the unit cell 2. Note that the load device 4 and the current detection unit 3 are the same as those in FIG. 3 and have been described in the “Prior Art” section, and therefore description thereof will be omitted here.

According to the above embodiment, the voltage of each unit cell 2 is constantly detected by the voltage detection unit 7 during the discharge of the battery pack 1, and when the voltage of any of the unit cells 2 becomes zero, the unit cell 2 is discharged. A control signal d is output from the control section 5 to the contact section 6 connected to the battery 2, whereby the contact section 6 is closed and the unit cell 2 is short-circuited. Even after that, such short-circuiting of the unit cells 2 is sequentially performed, and finally the voltages of all the unit cells 2 constituting the assembled battery 1 become zero. Therefore, the assembled battery 1 is completely discharged.

[0017]

[Effect of device]

 According to the present invention, as described in detail above with reference to the embodiments, the reverse charging of the unit cells is caused by sequentially short-circuiting the unit cells whose voltage becomes zero. Instead, the assembled battery can be completely discharged automatically. Therefore, there is no need to worry about reverse charging, and the conventional labor of disassembling each unit cell to perform complete discharge becomes unnecessary.

Further, since the voltage of each unit cell is constantly monitored, the performance of the unit cell can be evaluated.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram showing an example of a state in which some of the unit cells are reversed due to reverse charging.

FIG. 3 is a block diagram showing a configuration of an assembled battery discharging device according to a conventional technique.

[Explanation of symbols]

 1 assembled battery 2 unit cell 4 load device 5 control unit 6 contact unit 7 voltage detection unit a, b detection signal c, d control signal

Claims (1)

[Scope of utility model registration request] 1. A load device connected to an assembled battery formed by connecting a plurality of unit cells which are secondary batteries in series, and a load device connected to both poles of each unit cell to short-circuit between both poles of the unit cell. And a plurality of voltage detection units for detecting the voltage of each of the unit cells, and inputting detection signals from the voltage detection units to close the contact units corresponding to the completely discharged unit cells. And a control unit configured to short-circuit both electrodes of the unit cell.