JP5473277B2 - Charger - Google Patents

Description

The charging of the battery pack to have a plurality of secondary battery cells connected in series about the line UTakashi collector.

There is known a charging device that charges a battery pack including a plurality of secondary battery cells connected in series.
JP-A-11-275772

  In the conventional charging apparatus, the charging voltage is controlled so as not to exceed the overcharge protection voltage value as a whole of a plurality of cells connected in series.

  That is, since the charging voltage is not monitored for each of the plurality of cells, if the voltage balance of the plurality of cells is broken, a cell that exceeds the overcharge protection voltage value will be generated. There is.

The present onset Ming, for example, at the manufacturing stage, and an object thereof is to provide a charging apparatus capable of performing the dynamic Saku確 certification of the charging voltage control.

Charging apparatus according to the present invention, the a first battery cell, and the first secondary battery cells connected in series with the second secondary battery cells, and the first secondary battery cell No. a first terminal connected between the secondary battery cell, a second terminal connected to the temperature sensing element is an element used to detect the temperature, and the positive terminal, the negative terminal a charging apparatus for charging a battery pack having said first voltage measuring means for measuring the voltage of the positive terminal, a second voltage measuring means for measuring the voltage before Symbol first terminal, prior Symbol a third voltage measuring means for measuring the voltage of the second terminal, a current measuring means for measuring the charging current, on the basis of the voltage of the positive terminal and the voltage of the first terminal, the first a calculating means for calculating the voltage of the secondary battery cell and the voltage of the second secondary battery cell, before Symbol First storage means for storing a charge current pressure value corresponding to the voltage of the second terminal, when the voltage of the first secondary battery cell is greater than the voltage of the second secondary battery cell, The charging voltage is controlled so that the voltage of the first secondary battery cell does not exceed the charging voltage value corresponding to the voltage of the second terminal, and the voltage of the second secondary battery cell is the first voltage. Control means for controlling the charging voltage so that the voltage of the second secondary battery cell does not exceed the charging voltage value corresponding to the voltage of the second terminal when the voltage is higher than the voltage of the secondary battery cell ; Yes, and if the first mode is selected, said control means performs control for stopping the charging operation in response to that the charge current is equal to or less than a predetermined value is detected, the second When the mode is selected, the control means has the charging current becomes a predetermined value or less. Doo is equal to or not to perform a control for stopping the charging operation in response to detected.

According to the present invention, for example, in the manufacturing stage, it is possible to perform dynamic Saku確 certification of the charging voltage control.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is an external view of a charging device according to an embodiment of the present invention.

  The charging device 6 shown in FIG. 1 is a charging device that charges a battery pack with a midpoint terminal.

  The battery pack 1 has a + terminal (+) 2, a midpoint terminal (C) 3, a temperature terminal (T) 4, and a − terminal (−) 5.

  The charging device 6 includes a + terminal (+) 7, a midpoint terminal (C) 8, a temperature terminal (T) 9, and a − terminal (−) 10 as terminals corresponding to the terminals of the battery pack 1. .

  In the battery pack 1, two secondary battery cells (hereinafter abbreviated as cells) are connected in series.

  The midpoint terminal (C) 3 and the midpoint terminal (C) 8 function as output terminals that output a midpoint voltage between cells of the battery pack 1 (midpoint terminals connected between a plurality of secondary battery cells). To do.

  The temperature terminal (T) 4 and the temperature terminal (T) 9 function as output terminals that output the temperature of the battery pack 1.

  These corresponding terminals are connected to each other by mounting the battery pack 1 on the mounting portion 11 of the charging device 6.

  Electric power for charging by the charging device 6 can be supplied from a home AC power source (AC power source) via the AC cord 12 and the AC plug 13.

  When the battery pack 1 is attached to the charging device 6, the charging device 6 starts charging the battery pack 1.

  Whether or not the battery pack 1 is connected to the charging device 6 is determined by whether or not the thermistor 135 (temperature detection element) is connected to the temperature terminal 9.

  The thermistor 135 is connected between the temperature terminal 4 and the minus terminal 5 of the battery pack 1 and functions as temperature measuring means for the battery pack 1 as described later (see FIG. 2).

  The voltage (charging voltage) of the battery pack 1 being charged is detected by a charging control microcomputer 301 (see FIG. 2) built in the charging device 6.

  Further, the midpoint voltage 3 of the two cells 141 and 142 (see FIG. 2) connected in series is output from the midpoint terminal 3 of the battery pack 1.

  The charging control microcomputer 301 (control unit) determines each cell 141 based on the voltage at the + terminal 2 of the battery pack 1 (the voltage across the two cells connected in series) and the midpoint voltage at the midpoint terminal 3 during charging. , 142 is calculated.

  Then, the charge control microcomputer 301 controls the charge voltage so that the maximum charge voltage of the cell does not exceed the overcharge protection voltage value of the cell.

  The overcharge protection voltage value of the cell is stored in advance in a memory in the charge control microcomputer 301 in association with the temperature information.

  FIG. 2 is a block diagram showing a configuration of an electric circuit of the charging device 6 and the battery pack 1 shown in FIG.

  In FIG. 2, general configurations that are not necessary for the description of the present invention are omitted.

  The code | symbol attached | subjected to the component of the charging device 6 shown in FIG. 2 has shown the following element.

  Reference numeral 102 denotes an AC input unit, 103 denotes a primary power supply circuit, 104 denotes a transformer, 105 denotes a photocoupler, 106 denotes a secondary smoothing circuit, and 107 denotes a regulator.

  Reference numerals 108, 111, 112, 116, 118, 119, 120, 121, 122, 123, and 140 denote resistors. Reference numerals 109 and 110 denote operational amplifiers. Reference numeral 113 denotes a volume, and 114 denotes a quick charge switch. Reference numeral 117 denotes a trickle charge switch. Reference numerals 124, 138, and 139 denote switches.

  Reference numeral 7 denotes a positive terminal of the charging device 6, 8 denotes a middle terminal of the charging device 6, 9 denotes a temperature terminal of the charging device 6, and 10 denotes a negative terminal of the charging device 6.

  301 is a charging microcomputer, 302 is a memory, 303 is a voltage measuring unit for the midpoint terminal 8, 304 is a mode selection input unit, 305 is a battery pack voltage input unit, 306 is a temperature terminal voltage input unit, and 307 is a charging current input unit. is there.

  308 is a charging voltage setting output (1), 309 is a charging voltage setting output (2), 310 is a charging voltage setting output (3), and 311 is a charging current setting output. Reference numerals 312, 314, and 316 denote resistors. Reference numerals 313 and 315 denote switches, and reference numeral 317 denotes a display unit.

  The reference numerals of the constituent elements of the battery pack 1 shown in FIG. 2 indicate the following elements.

  Reference numeral 2 denotes a positive terminal of the battery pack 1, 3 denotes a middle point terminal of the battery pack 1, 4 denotes a temperature terminal of the battery pack 1, and 5 denotes a negative terminal of the battery pack 1.

  Reference numeral 134 denotes a battery protection circuit, 135 denotes a thermistor, 136 denotes a charge protection FET, 137 denotes a discharge protection FET, and 141 and 142 denote cells.

  When AC power is input to the AC input unit 102, the AC power is supplied to the transformer 104 via the primary power supply circuit 103.

  The transformer 104 performs voltage conversion from the primary side high voltage to the secondary side low voltage, and also separates the primary side and secondary side GND lines.

  The secondary output of the transformer 104 is rectified by the secondary smoothing circuit 106 and output to the subsequent charge control circuit.

  The regulator 107 converts the output voltage from the secondary smoothing circuit 106 to 4.2 V, which is the standard value (overcharge protection voltage value) of the maximum charging voltage of each cell 141, 142 of the battery pack 1, and outputs the converted voltage.

  The power of 4.2 V voltage from the regulator 107 is used as power for adjusting the cell voltage of the battery pack 1.

  The secondary side voltage of the transformer 104 is divided by a voltage feedback resistor 112 and a volume 113 for adjusting the maximum value of the charging voltage.

  The secondary side voltage of the transformer 104 is controlled by the charge control microcomputer 301 via the operational amplifier 109 and the photocoupler 105.

  The output voltage of the regulator 107 is supplied to the temperature terminal 9 of the charging device 6 via the resistor 119.

  The switches 138 and 139 of the battery pack 1 are switches for preventing voltage imbalance between the cells 141 and 142 and overdischarge of the cells 142.

  When no voltage is generated at the temperature terminal 4 of the battery pack 1, that is, when the charging device 6 is not connected, the switches 138 and 139 are OFF.

  At this time, the midpoint voltage between the cell 141 and the cell 142 is not output to the midpoint terminal 3 of the battery pack 1.

  Even if the middle point terminal 3 of the battery pack 1 is short-circuited with the + terminal 2 or the − terminal 5 in this state, the cell 141 or the cell 142 is not discharged, thereby preventing cell imbalance and cell overdischarge. It becomes possible.

  When the battery pack 1 is connected to the charging device 6, a voltage obtained by dividing the output voltage of the regulator 107 by the resistor 119 and the thermistor 135 is generated at the temperature terminal 4 of the battery pack 1.

  The charge control microcomputer 301 detects the attachment of the battery pack 1 by detecting the voltage divided by the resistor 119 and the thermistor 135 via the temperature terminal 9 and starts charging control to the battery pack 1. .

  The switches 138 and 139 of the battery pack 1 are turned on when a voltage is generated at the temperature terminal 4. When the switches 138 and 139 are turned on, the midpoint voltage between the cell 141 and the cell 142 is output to the midpoint terminal 3 via the resistor 140.

  Since the resistance value of the thermistor 135 varies depending on the internal temperature of the battery pack 1, the thermistor 135 is used as a sensor for measuring the internal temperature of the battery pack 1.

  The charging device 6 basically determines a charging voltage and a charging current when charging the battery pack 1 based on the internal temperature of the battery pack 1 measured by the thermistor 135.

  Details of this charge control will be described later.

  The charging control microcomputer 301 of the charging device 6 detects the mounting of the battery pack 1 and the internal temperature based on the voltage level of the temperature terminal 9.

  The charging control microcomputer 301 measures the charging voltage via the resistors 120 and 121.

  When the charging control microcomputer 301 detects the mounting of the battery pack 1 based on the voltage at the temperature terminal 9, the charging control microcomputer 301 measures the charging voltage of the battery pack 1 and the midpoint voltage of the midpoint terminal 3.

  That is, the charge control microcomputer 301 functions as a battery pack voltage measuring unit and a midpoint terminal voltage measuring unit.

  The measured midpoint voltage is used to individually calculate the charging voltages of the cells 141 and 142.

  When the voltage of the battery pack 1 is lower than a preset specified value (Vadj) and the potential difference between the cell 141 and the cell 142 is higher than a threshold value (VD), that is, the voltage control microcomputer 301 If the voltage collapses, the cell voltage is adjusted.

  This cell voltage adjustment eliminates the potential difference between the cell 141 and the cell 142 before charging. Thereby, the battery pack 1 can be suitably charged.

  The cell voltage adjustment is performed by charging and discharging the cell 142 on the negative electrode side of the battery pack 1.

  That is, when the voltage of the cell 142 is higher than the voltage of the cell 141, the switch 124 is turned on to discharge the cell 142 from the midpoint terminal 8 via the resistors 140 and 123.

  When the voltage of the cell 142 is lower than the voltage of the cell 141, the cell 142 is charged from the midpoint terminal 8 through the resistors 122 and 140.

  In the cell voltage adjustment of the present embodiment, charging / discharging is not performed on the cell 141 on the positive electrode side of the battery pack 1.

  Instead of the cell voltage adjustment of the present embodiment, a resistor and a switch (not shown) are provided between the + terminal 7 and the midpoint terminal 8 to charge the cell 142 on the negative electrode side and the cell on the positive electrode side It is also possible to shorten the cell voltage adjustment time by performing the discharge 141.

  When charging / discharging from the midpoint terminal 8 during the cell voltage adjustment, the resistor 140 causes a potential difference between the actual midpoint voltage between the cells 141 and 142 and the measured voltage at the midpoint terminal 8. .

  For this reason, the voltage of the midpoint terminal 8, that is, the midpoint voltage is measured by temporarily stopping the cell voltage adjustment and then restarting the cell voltage adjustment.

  Note that the midpoint voltage may be measured for each preset period, and the measurement period may be changed depending on the voltage, temperature environment, or the like as necessary.

  The cell voltage adjustment is terminated when the potential difference between the cell 141 and the cell 142 becomes equal to or smaller than a preset value, or when a specified time has elapsed, and the process proceeds to trickle charging.

  The trickle charge is performed by supplying a charging current limited by the resistor 116 to the battery pack 1.

  This trickle charging is performed when the voltage of the battery pack 1 is less than the voltage at which rapid charging is possible, and is terminated when the voltage at which rapid charging is possible is reached.

  In the quick charge, in the initial stage of charging, constant current charging for supplying a constant charging current to the battery pack 1 is performed, and thereafter, constant voltage charging for supplying a constant charging voltage to the battery pack 1 is performed.

  The charging current value is converted into a voltage level via the resistor 118.

  The setting of the charging current value is determined by a divided value obtained by dividing the output voltage of the regulator 107 by the resistors 108 and 111.

  The charging current value is controlled via the operational amplifier 110 and the photocoupler 105.

  When the charging current flows, the contact resistance between the positive terminal 7 of the charging device 6 and the positive terminal 2 of the battery pack 1, and the contact resistance between the negative terminal 10 of the charging device 6 and the negative terminal 5 of the battery pack 1. A potential difference occurs.

  The charging current is also applied to resistance components such as a circuit resistance between the cell 141 and the + terminal 2, a circuit resistance between the cell 142 and the-terminal 5, and a circuit resistance between the cell 141 and the cell 142. A potential difference is caused by the flow of.

  Therefore, the charging control microcomputer 301 corrects the above-described potential difference when calculating the voltage of the cell 141 and the cell 142 based on the charging voltage of the battery pack 1 and the midpoint voltage of the midpoint terminal 8.

  When the charging current value is sufficiently small, the above-described potential difference is also small. Therefore, when the charging current value is smaller than a preset value, there is no need to correct.

  The charging control microcomputer 301 stores an appropriate charging voltage value of the cell in a built-in memory (not shown).

  This appropriate charging voltage value is a voltage value for overcharge protection (overcharge protection voltage value), and varies depending on the temperature.

  In the present embodiment, in order to save memory capacity, a large number of overcharge protection voltage values are not stored in units of small temperature differences, but overcharge protection voltage values for each of the five temperature ranges as shown in Table 1. Is remembered.

  Note that the charging control microcomputer 301 also changes the charging current value for each of the five temperature ranges.

  Table 1 shows a temperature range-overcharge protection voltage value table and a temperature range-charge current value table stored in the memory (first storage means) of the charge control microcomputer 301.

  This table shows the overcharge protection voltage value and the charging current value set for each temperature range.

  That is, the charging control microcomputer 301 detects the internal temperature of the battery pack 1 during the rapid charging, and determines the overcharge protection voltage value and the charging current value according to the detected internal temperature.

  The charging control microcomputer 301 during charging controls the charging voltage of the battery pack 1 so that the charging voltage of the cell having the higher charging voltage does not exceed the overcharge protection voltage value of the cell. That is, the charging control microcomputer 301 sets the charging voltage for the battery pack so that the voltage of the secondary battery cell having the maximum voltage among the plurality of secondary battery cells does not exceed the overcharge protection voltage value stored in the memory. Control.

  In the charge voltage control, a resistor 203 is connected in parallel to the volume 113, and a switch 204 is connected in series to the resistor 203. In parallel with the volume 113, a resistor 205 having a resistance value different from that of the resistor 203 and a switch 206 are connected. In parallel with the volume 113, a resistor 312 having a resistance value different from that of the resistors 203 and 205 and a switch 313 are connected.

  By turning on the switch 204, the charging voltage is set to the first overcharge protection voltage value. By turning on the switch 206, the charging voltage is set to the second overcharge protection voltage value. By turning on the switch 313, the charging voltage is set to the third overcharge protection voltage value. Furthermore, the charging voltage is set to the fourth overcharge protection voltage value by simultaneously turning on the switches 204, 206, and 313.

  Further, as means for changing the charging current, a resistor 201 and a switch 202 are connected in parallel to the resistor 111.

  Furthermore, by providing more resistors and switches as described above, the charging voltage (overcharge protection voltage value) and the charging current can be changed more finely.

  The charging control microcomputer 301 measures the charging current by detecting the potential difference of the resistor 118 that converts the charging current value into a voltage level.

  The charging control microcomputer 301 detects an increase in charging voltage and a decrease in charging current during rapid charging, and determines whether or not the rapid charging is completed based on the degree of the increase and decrease.

  The charging device according to the present embodiment stores a first mode in which charging control during charging is performed, a second mode in which a charging voltage and a charging current are set according to the voltage at the temperature terminal 9, and a third mode. A memory 302 is included.

  In the first mode, the charging control of the battery pack 1 is performed in the normal charging control mode.

  In the second mode, the charging control microcomputer 301 measures the voltage at the temperature terminal 9 by the temperature terminal voltage measuring unit 306, and the switch 204 is based on the data representing the relationship between the temperature terminal voltage and the charging output stored in the memory 302. , 206 and 313 are controlled. The memory 302 functions as a second storage unit and a third storage unit.

Here, the data representing the relationship between charge output temperature terminal voltage to be stored in the memory 302 will be described with reference to FIG. 1 0.

1 0, when the manufacturing test equipment to set the temperature terminal voltage (Vt) to 4.0V <Vt conditions, next switch 204,206,313 are all ON, the output voltage at that time is set to 8.40V .

  Similarly, when the condition of 3.5V <Vt ≦ 4.0V is set, the switches 204, 206, and 313 are sequentially set to OFF, ON, and ON, and the output voltage is set to 8.35V.

  In this way, the switch state is changed by sequentially changing the temperature terminal voltage in the production inspection facility, and the output voltage is controlled to check all the conditions.

  In the third mode, the charge control microcomputer 301 measures the voltage at the temperature terminal 9 and measures the voltage at the temperature terminal 9 and switches the switch 202 based on the data representing the relationship between the temperature terminal voltage and the charge output stored in the memory 302. Control.

1 0, for example in a temperature terminal voltage (Vt) is 0.5V <Vt conditions, the switch 202 is set to OFF, the output current is set to 700 mA.

  Under the condition that the temperature terminal voltage (Vt) is Vt ≦ 0.5V, the switch 202 is set to ON and the output current is set to 500 mA.

  Further, in the charging device of the present embodiment, control is performed so that the completion of charging is not detected during operation in the second mode and the third mode.

  Further, in the charging device of the present embodiment, a display unit is provided, and when a predetermined control operation is not performed during operation in the second mode and the third mode, an abnormality display is performed on the display unit 317.

  This embodiment shows an example in which data representing the relationship between the temperature terminal voltage and the charging output is stored together, but a plurality of resistors and switches are provided in parallel with the resistor 111 to finely adjust the charging current. In this case, a method of inspecting only the third mode is also conceivable.

  When inspecting only the third mode, it is possible to store only data indicating the relationship between the temperature terminal voltage and the charging current in the data indicating the relationship between the temperature terminal voltage and the charging output.

  In the case where only the charging current is inspected, the charging control by the midpoint terminal is technically irrelevant.

  Next, the outline of the flow of the quick charge control in the embodiment will be described based on the flowchart of FIG.

  The charge control microcomputer 301 detects whether the voltage of the mode selection input unit 304 is “H” level or “L” level (step S2001).

  When the input of the switch 315 is connected to the resistor 314 side, the mode selection input unit 304 becomes “H” level, so that the charging control microcomputer 301 proceeds to step S1 and performs the first charging operation. Control in the mode.

  When the input of the switch 315 is connected to the resistor 316 side, the mode selection input unit 304 becomes “L” level, so that the charge control microcomputer 301 can perform the manufacturing inspection in the second mode and the third mode. Take control.

  In the manufacturing inspection mode (second mode, third mode), the charge control microcomputer 301 first measures the voltage at the temperature terminal 9 by the temperature terminal voltage measurement unit 306 (step S2002).

  The charge control microcomputer 301 refers to the measurement result of the temperature terminal voltage and data representing the relationship between the temperature terminal voltage and the charge output stored in the memory 302, and controls the switches 204, 206, and 313 to set the output voltage. (Step S2003).

  The charge control microcomputer 301 refers to the measurement result of the temperature terminal voltage and data representing the relationship between the temperature terminal voltage and the charge output stored in the memory 302, and controls the switch 202 to set the output current (step S2004). ).

  Next, the charge control microcomputer 301 divides the voltage at the + terminal 7 by the resistors 120 and 121 and measures the voltage by the pack voltage measurement unit 305 (step S2005).

  Next, the charging control microcomputer 301 measures the output current with the charging current measuring unit 307 (step S2006).

  When measuring the output current, generally, a pseudo battery pack is connected by an inspection device, and conditions under which a charging current can be generated are set.

  Then, the charging control microcomputer 301 determines whether or not the output voltage and output current measured in steps S2005 and S2006 are out of the data representing the relationship between the temperature terminal voltage and the charging output stored in the memory 302 ( Step S2007).

  Then, when the charge output deviates from the data representing the relationship between the temperature terminal voltage and the charge output, an abnormal display is performed on the display unit (step S2008).

  The abnormality display may be a display by blinking an LED, a display by sound, or the like.

  Moreover, although illustration is abbreviate | omitted, you may communicate with inspection equipment and you may display on inspection equipment.

  In step S2001, when the input of the switch 315 is connected to the resistor 314 side, the mode selection input unit 304 becomes “H” level. At this time, the charging control microcomputer 301 performs control in the first mode in which a normal charging operation is performed.

  The charge control microcomputer 301 determines whether or not the battery pack 1 is attached (step S1).

  Specifically, whether or not the battery pack 1 is mounted is determined based on whether or not a voltage obtained by dividing the output voltage of the regulator 107 by the resistor 119 and the thermistor 135 is generated at the temperature terminal 9.

  When the battery pack 1 is mounted, the temperature of the battery pack 1, the voltage at the midpoint terminal 8 (the midpoint voltage), and the voltage of the battery pack 1 (V7: charging voltage at the + terminal 7) are sequentially detected. (Steps S2 to S4).

  Details of the voltage detection processing of the battery pack 1 will be described later.

  Next, the charge control microcomputer 301 calculates the cell voltages of the cells 141 and 142 based on the detected midpoint voltage of the midpoint terminal 8 and the voltage of the battery pack 1 (step S5).

  Details of this cell voltage calculation process will be described later.

  Next, the charge control microcomputer 301 determines whether or not the detected voltage (V7) of the battery pack 1 is lower than a specified value (Vadj) (step S6).

  As a result, if the voltage (V7) of the battery pack 1 is lower than the specified value (Vadj), the charge control microcomputer 301 performs a cell voltage adjustment process (step S7).

  The first set value (Vadj) is set based on the lowest voltage at which an electronic device using the battery pack 1 as a power source can operate. By setting the first set value (Vadj) in this way, cell voltage adjustment processing can be performed in order to align the cell voltages at the end of discharge.

  As described above, the cell voltages at the end of discharge are made uniform because if the cell voltages are aligned at a high cell voltage, the cell voltage decreases sharply at the end of discharge and it is necessary to increase the operating voltage range of the electronic device. This is because the usable time of the electronic device is reduced.

  Details of this cell voltage adjustment processing will be described later.

  If the voltage (V7) of the battery pack 1 is equal to or higher than the first set value (Vadj), the charge control microcomputer 301 determines the cell charge voltage set value based on the detected temperature of the battery pack 1 (step S8).

  Since the battery pack 1 is charged when it is equal to or higher than the first set value (Vadj), in the present embodiment, the first set value (Vadj) is a charge start voltage for starting charging the battery pack 1. It has become.

  Although details of the determination process of the cell charge voltage setting value will be described later, in the present embodiment, the above-described overcharge protection voltage value is determined as the cell charge voltage value.

  Next, the charging control microcomputer 301 determines a charging current value (Ichg) based on the detected temperature of the battery pack 1, and starts rapid charging (steps S9 and S10).

  Details of the charging current value determination process will be described later.

  When the charge control microcomputer 301 starts the quick charge, the cell voltage (cell charge voltage) of any of the cells 141 and 142 reaches the set value of the cell charge voltage determined in step S8, that is, the overcharge protection voltage value. It is determined whether or not (step S11).

  If neither of the cells 141 and 142 has reached the overcharge protection voltage value, the charging device 6 performs constant current control (step S12).

  Details of this constant current control process will be described later.

  In addition, since the cell voltage imbalance of the cells 141 and 142 has been eliminated by the adjustment process in step S7, the deviation of the timing at which the charging voltage of the cells 141 and 142 reaches the above-described overcharge protection voltage value is reduced. Yes.

  On the other hand, when the cell charge voltage of any of the cells 141 and 142 reaches the overcharge protection voltage, the charge control microcomputer 301 controls the charge voltage so as to maintain the overcharge protection voltage value without exceeding it. Do.

  Then, the charging control microcomputer 301 determines whether or not the charging amount of the cells 141 and 142 has reached a predetermined value due to a decrease in charging current (step S13). If the charging amount has not reached the predetermined value, the process goes to step S1. If the predetermined value is reached, the quick charge control is terminated. That is, the charging control microcomputer 301 completes the charging operation for the battery pack 1 when the charging current becomes a predetermined value or less.

  Next, details of the temperature detection process of the battery pack 1 in step S2 of FIG. 3 will be described in detail based on the flowchart of FIG.

  In this temperature detection process, the charge control microcomputer 301 first measures the voltage at the temperature terminal 9 (step S21).

  Then, the charging control microcomputer 301 refers to the temperature / voltage table in which the temperature of the battery pack 1 corresponding to the voltage at the temperature terminal 9 is registered in the memory (step S22).

  Next, the charge control microcomputer 301 determines the temperature of the thermistor 135 corresponding to the voltage of the temperature terminal 9 referred to as the temperature of the battery pack 1 (step S23), and returns to the flow of FIG.

  Next, details of the cell voltage calculation process in step S5 of FIG. 3 will be described in detail based on the flowchart of FIG.

  In this cell voltage calculation process, the charge control microcomputer 301 first refers to the voltage (V7) of the battery pack 1 and the voltage (V8) of the midpoint terminal 8 (steps S51 and S52).

  Then, the charging control microcomputer 301 calculates the potential difference Vz2 from the −contact of the cell 142 to the −terminal 10 (step S53).

  Specifically, the charging control microcomputer 115 detects the charging current value (Ichg). Then, the sum (Z2) of resistance components from the −contact to the −terminal 10 of the cell 142 stored in the built-in memory 149 of the charge control microcomputer 115 is read out and calculated by an arithmetic expression Vz2 = (Ichg × Z2). The

  This potential difference Vz2 is calculated from the resistance component of the GND line and the charging current value, as shown in the above arithmetic expression.

  That is, the potential difference Vz2 is a sum of the contact resistance between the negative terminal 10 and the negative terminal 5, the drain-source resistance Rds (ON) of the charge protection FET 136 and the discharge protection FET 137, and the pattern resistance (Z2). The charge current value (Ichg) is multiplied.

  Next, the charge control microcomputer 301 calculates the voltage (Vc 142) of the cell 142 (step S54).

  The voltage (Vc 142) of the cell 142 is obtained by subtracting the potential difference Vz 2 from the −contact to the −terminal 10 of the cell 142 from the voltage (V 8) of the midpoint terminal 8.

  Next, the charge control microcomputer 301 calculates the potential difference Vz1 from the + contact of the cell 141 to the + terminal 7 (step S55).

  Specifically, the charging control microcomputer 115 detects the charging current value (Ichg). Then, the sum (Z1) of resistance components from the + contact of the cell 141 stored in the built-in memory 149 of the charge control microcomputer 115 to the + terminal 7 is read out and calculated by an arithmetic expression Vz1 = (Ichg × Z1). The

  That is, the potential difference Vz1 is obtained by multiplying the sum (Z1) of the contact resistance and the pattern resistance between the + terminal 7 and the + terminal 2 by the charging current value (Ichg).

  Next, the charge control microcomputer 301 calculates the voltage (Vc141) of the cell 141 (step S56), and returns to the flow of FIG.

  The voltage (Vc141) of the cell 141 is obtained by subtracting Vz1, the voltage (Vc142) of the cell 142, and Vz2 from the voltage (V7) of the + terminal 7.

  Next, details of the cell voltage adjustment processing in step S7 of FIG. 3 will be described in detail based on the flowchart of FIG.

  In this cell voltage adjustment process, the charge control microcomputer 301 first starts a timer (step S71), and the timer time (Tm) is counted up.

  Next, charging / discharging to the cell 141 and the cell 142 is stopped (step S72).

  After stopping the charging / discharging, the voltage (V7) of the battery pack 1 and the voltage (V8) of the midpoint terminal 8 are detected (step S73, step S74).

  The voltage (Vc141) of the cell 141 and the voltage (Vc142) of the cell 142 are calculated from the voltage (V7) of the battery pack 1 detected in step S73 and step S74 and the voltage of the middle point terminal 8 (V8: middle point voltage). (Step S75).

  The voltage (Vc141) of the cell 141 and the voltage (Vc142) of the cell 142 calculated in step S75 are voltages in a state where charging / discharging of the cell 141 and the cell 142 is stopped. Accordingly, the voltage (Vc141) of the cell 141 calculated in step S75 and the voltage (Vc142) of the cell 142 do not match the voltage (Vc141) of the cell 141 calculated in step S5 and the voltage (Vc142) of the cell 142.

  Further, since the voltage (V7) of the battery pack 1 and the midpoint voltage (V8) of the midpoint terminal 8 are detected in a state where charging / discharging is stopped, the contact is different from the cell voltage calculation in step S5 of FIG. The potential difference due to resistance and circuit resistance is not considered.

  The charge control microcomputer 301 determines whether or not the difference between the voltage of the cell 141 (Vc141) and the voltage of the cell 142 (Vc142) is smaller than a threshold value (VD) (step S76).

  When the difference between the voltage (Vc141) of the cell 141 and the voltage (Vc142) of the cell 142 is smaller than the threshold value (VD), the process returns to the flow of FIG. 3 without performing the cell voltage adjustment process. That is, when the voltage of the cell 141 (Vc141) and the voltage of the cell 142 (Vc142) are substantially the same voltage, the cell voltage adjustment process is not performed and the process returns to the flow of FIG.

  On the other hand, when the difference between the voltage of the cell 141 (Vc141) and the voltage of the cell 142 (Vc142) is equal to or greater than the threshold (VD), the voltage of the cell 141 (Vc141) and the voltage of the cell 142 (Vc142) Which voltage is higher is determined (step S77).

  When the voltage (Vc142) of the cell 142 is higher than the voltage (Vc141) of the cell 141, the charge control microcomputer 301 discharges the cell 142 (step S78).

  The cell 142 is discharged through the resistors 123 and 140 by turning on the switch 124.

  On the other hand, when the voltage (Vc142) of the cell 142 is lower than the voltage (Vc141) of the cell 141, the charge control microcomputer 301 charges the cell 142 (step S79).

  The cell 142 is charged through the resistors 122 and 140 by turning off the switch 124 and turning on the switch 139.

  The charge control microcomputer 301 again determines whether or not the difference between the voltage of the cell 141 (Vc141) and the voltage of the cell 142 (Vc142) is smaller than the threshold value (VD) (step S80-1).

  When the difference between the voltage (Vc141) of the cell 141 and the voltage (Vc142) of the cell 142 is smaller than the threshold value (VD), the cell voltage adjustment processing is not performed and the process returns to the flow of FIG. That is, when the voltage of the cell 141 (Vc141) and the voltage of the cell 142 (Vc142) are substantially the same voltage, the cell voltage adjustment processing is not performed and the process returns to the flow of FIG.

  On the other hand, when the difference between the voltage (Vc141) of the cell 141 and the voltage (Vc142) of the cell 142 is equal to or greater than a threshold value (VD), the timer time (Tm) is equal to or greater than a preset limit time (TL). (Step S80-2).

  When the timer time (Tm) becomes equal to or longer than the limit time (TL), the process returns to the flow of FIG.

  If the timer time (Tm) is not the limit time (TL), the process returns to step S72.

  In this way, the cell voltage adjustment process is executed until the difference between the voltage (Vc141) of the cell 141 and the voltage (Vc142) of the cell 142 becomes smaller than the threshold value (VD).

  Next, details of the determination process of the cell charging voltage set value in step S8 of FIG. 3 will be described in detail based on the flowchart of FIG.

  In the determination process of the cell charge voltage setting value, the charge control microcomputer 301 first refers to the temperature of the battery pack 1 detected in step S2 (step S81).

  Then, the charge control microcomputer 301 refers to the temperature range-overcharge protection voltage value table registered in the memory in the charge control microcomputer 301 (step S82).

  The overcharge protection voltage value registered in this table is an upper limit voltage value for overcharge protection corresponding to the temperature range.

  Next, the charge control microcomputer 301 reads the overcharge protection voltage value registered as the upper limit voltage value for overcharge protection corresponding to this temperature range, and determines this overcharge protection voltage value as the cell charge voltage setting value. Then (step S83), the process returns to the flow of FIG.

  Next, details of the determination process of the charging current value in step S9 of FIG. 3 will be described in detail based on the flowchart of FIG.

  In the charging current value determination process, the charging control microcomputer 301 first refers to the temperature of the battery pack 1 detected in step S2 (step S91).

  Then, the charge control microcomputer 301 refers to the temperature range-charge current value table registered in the memory in the charge control microcomputer 301 to determine the charge current value of the battery pack 1 (step S92), and the flow of FIG. Return to

  Next, details of the charging voltage control process in step S12 of FIG. 3 will be described in detail based on the flowchart of FIG.

  In this charging voltage control process, the charging control microcomputer 301 first refers to the calculated voltage of the cell 141 (Vc141: cell charging voltage) and the voltage of the cell 142 (Vc142: cell charging voltage) (step S1201).

  Next, the charge control microcomputer 301 determines whether or not the voltage (Vc141) of the cell 141 is larger than the voltage (Vc142) of the cell 142 (step S1202).

  When the voltage (Vc141) of the cell 141 is larger than the voltage (Vc142) of the cell 142, the charging voltage is controlled so that the cell 141 does not exceed the overcharge protection voltage value (step S1203).

  On the other hand, when the voltage (Vc141) of the cell 141 is smaller than the voltage (Vc142) of the cell 142, the charging voltage is controlled so that the cell 142 does not exceed the overcharge protection voltage value (step S1204). Return to the flow.

  As described above, when the mode selection input is set to the manufacturing inspection mode, the charge control microcomputer 301 is controlled in the second and third modes and measures the temperature terminal voltage set in the manufacturing inspection facility. .

  Then, according to the measurement result of the temperature terminal voltage, the output voltage is set by controlling the switches 204, 206, and 313 with reference to the data representing the relationship between the temperature terminal voltage and the charge output stored in the memory 302. .

  Further, when the value of the temperature terminal voltage is a voltage for controlling the output current, the switch 202 is controlled to set the output current.

  When operating in these second and third modes, if the detection of the completion of charging is detected by detecting a decrease in the charging current as in normal charging, the charging completion condition will occur during the inspection. Charging completion detection is not performed.

  Further, the output voltage and output current are measured to detect whether the specified output voltage and output current are generated. When the specified output is not output, an abnormality is displayed on the display unit.

  That is, in the present embodiment, in the charging device that controls the charging voltage so as not to exceed the overcharge protection voltage value for each of the plurality of cells connected in series, charging voltage control and charging current control are performed at the manufacturing stage. It has become possible to confirm that it works reliably.

  The present invention is not limited to this embodiment, and can also be applied to, for example, a battery pack in which three or more cells are connected in series. In this case, (the number of cells minus 1) midpoint terminals are provided, and the midpoint voltage between the cells is detected.

  A dedicated IC can be used instead of the charge control microcomputer. The temperature of the battery pack may be detected using a temperature detection IC instead of the thermistor. It is also possible to provide a terminal for performing communication between the battery pack and the charging device, obtain charging voltage information of each cell from a memory built in the battery pack, and adjust and control the charging voltage.

It is an external view of the charging device which concerns on embodiment of this invention. It is a block diagram which shows the structure of the electric circuit of the charging device shown in FIG. 1, and a battery pack. 2 is a flowchart illustrating an outline of an operation flow of the charging apparatus illustrated in FIG. 1. It is a flowchart which shows the detail of the battery pack temperature detection process in step S2 of FIG. It is a flowchart which shows the detail of the cell voltage calculation process in step S5 of FIG. 4 is a flowchart showing details of a cell voltage adjustment process in step S7 of FIG. 3. It is a flowchart which shows the detail of the determination process of the cell charge voltage setting value in step S8 of FIG. It is a flowchart which shows the detail of the determination process of the charging current value in step S9 of FIG. It is a flowchart which shows the detail of the charging voltage control process in FIG.3 S12. It is data representing the relationship between the temperature terminal voltage and the charge output.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery pack 6 Charging device 7 + terminal of charging device 8 Middle terminal of charging device 9 Temperature terminal of charging device 10 − terminal of charging device 135 Thermistor 301 Charge control microcomputer 302 Memory

Claims (4)

A first secondary battery cells, and the and the first secondary battery cells connected in series with the second secondary battery cell, the first secondary battery cell and the second rechargeable battery cell a first terminal connected between a second terminal connected to the temperature sensing element is an element used to detect the temperature, and the positive terminal, charging for charging a battery pack and a negative electrode terminal A device,
First voltage measuring means for measuring the voltage of the positive terminal ;
A second voltage measuring means for measuring the voltage before Symbol first terminal,
A third voltage measuring means for measuring the voltage before Symbol second terminal,
Current measuring means for measuring the charging current;
On the basis of the voltage of the positive terminal and the voltage of the first terminal, and calculating means for calculating the voltage of the voltage between the second secondary battery cell of the first secondary battery cell,
First storage means for storing a pre-Symbol charge current pressure value corresponding to the voltage of the second terminal,
When the voltage of the first secondary battery cell is larger than the voltage of the second secondary battery cell, the voltage of the first secondary battery cell corresponds to the voltage of the second terminal. The charging voltage is controlled so as not to exceed the value, and when the voltage of the second secondary battery cell is larger than the voltage of the first secondary battery cell, the voltage of the second secondary battery cell is have a control means for controlling the charging voltage not to exceed the charging voltage value corresponding to the voltage of the second terminal,
When the first mode is selected, the control means performs control for stopping the charging operation in response to detecting that the charging current has become a predetermined value or less,
When the second mode is selected, the control means does not perform control for stopping the charging operation in response to detecting that the charging current has become a predetermined value or less. A charging device characterized by the above. If the previous SL second mode is selected, or the control unit performs a charging voltage, the first based on a charge voltage stored in the storage means, a display for notifying the abnormality The charging device according to claim 1, wherein it is determined whether or not . A second storage means for storing a charge current current values corresponding to the voltage of the second terminal,
Said control means, based on the charge current value corresponding to the voltage of the second terminal, the charging apparatus according to claim 1 or 2, characterized in a Turkey to control the charging current. When the second mode is selected, the control means performs display for notifying abnormality based on the charging current and the charging current value stored in the second storage means. The charging device according to claim 3, wherein the charging device is determined.

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