JP2010008133A - Portable charger, and deterioration diagnosis method of secondary battery used therefor - Google Patents

Abstract

[PROBLEMS] To quickly predict the degree of deterioration without being affected by the degree of deterioration of individual secondary batteries and the difference in charge amount when assembled, and to safely use secondary batteries with different degrees of deterioration and charge amounts. A portable charger and a method for diagnosing its deterioration can be provided at low cost.
In a portable charger capable of storing two or more rechargeable batteries in a replaceable manner, preliminary charging is performed for a predetermined time at a current of 0.1 to 0.3 C. Diagnose the degree of deterioration based on the difference in battery voltage, and if there is a secondary battery that is suspected of being deteriorated, charge it to a fully charged state, then perform pulse discharge, and check the battery voltage immediately before and during pulse discharge. The secondary battery internal resistance value is calculated using the difference and the amount of current during pulse discharge, and the degree of deterioration of the secondary battery is diagnosed based on the calculated internal resistance value. By charging individually, secondary batteries with different degrees of deterioration and the amount of charge when assembled are safely charged.
[Selection] Figure 1

Description

  The present invention relates to a portable charger that can store two or more rechargeable batteries in a replaceable manner, and more particularly to a deterioration diagnosis method and a charging method for the rechargeable battery.

  A device using a secondary battery includes a battery management device that monitors the voltage, charge / discharge current, temperature, and the like of the secondary battery and performs charge / discharge control, remaining amount estimation, deterioration diagnosis, and the like. In general, such a battery management device is integrated with a secondary battery to form a battery pack. As a method for diagnosing the deterioration of a battery used in a battery management device, a method for determining the deterioration of a battery based on the internal resistance of the battery is generally used. The positive / negative of a battery pack in which a plurality of secondary battery cells are connected in series. A short-circuit pulse discharge circuit with a constant current is connected between both terminals to discharge the assembled battery for a short time, and the discharge capacity and output characteristics decrease from the degree of change in the battery voltage during the predetermined time zone during this short-time discharge. Etc. are determined (for example, refer to Patent Document 1).

In addition, a method has also been proposed in which the voltage at both ends of the assembled battery during trickle charging is compared with a reference voltage by a comparison circuit, and the deterioration is determined when the voltage at both ends of the assembled battery becomes equal to or higher than the reference voltage. Since the internal resistance of the deteriorated battery increases, the voltage becomes higher than that of a normal battery even in trickle charging of about 1 / 20C. Therefore, when the voltage during trickle charging becomes larger than a specified value, it is determined that the battery has deteriorated (for example, see Patent Document 2).
JP 2001-296341 A Japanese Patent Laid-Open No. 08-293329

  As disclosed in Patent Document 1, according to the method in which the secondary battery is pulse-discharged with a constant current, the deterioration of the battery can be estimated with a certain degree of accuracy. However, since the secondary battery generates electricity by a chemical reaction, even if it is the same active substance or rated one, the current internal resistance differs depending on the individual neglected state, use state, temperature environment, and the like. As a result, in order to accurately estimate the deterioration state, it is necessary to collect actually measured data over a long period of time and set a data table. In addition, as disclosed in Patent Document 2, a method for detecting the battery voltage during trickle charging has been proposed. However, according to this method, the accuracy of deterioration diagnosis is poor and only rough determination can be made.

  Furthermore, the batteries to which such a deterioration diagnosis method can be applied are limited. That is, it can be applied only to secondary batteries capable of continuous trickle charge, such as nickel / cadmium secondary batteries, and other secondary batteries such as nickel / hydrogen secondary batteries, lead acid storage batteries and lithium ion secondary batteries. Etc. are difficult to apply. Nickel-hydrogen secondary batteries require intermittent charging to prevent overcharging. Moreover, in a lead acid storage battery and a lithium ion secondary battery, it is necessary to perform constant voltage charge.

The present invention relates to a plurality of secondary battery deterioration diagnosis methods, the step of forming a charging path for individually charging each secondary battery based on a command signal issued by a control unit, and the command signal issued by the control unit. A step of detecting the voltage of each secondary battery based on the above, and a preliminary charging for charging each secondary battery with a current of 0.1 to 0.3 C for a predetermined time based on a command signal issued by the control unit, Detecting a voltage of each secondary battery during pre-charging based on a command signal issued by the control unit; calculating a difference between the two voltages; and a degree of deterioration of each secondary battery based on the difference between the two voltages If there is a secondary battery that is suspected of being deteriorated, a step of charging the secondary battery individually until it is fully charged based on a command signal issued by the control unit, the control unit To the command signal Therefore, the secondary battery is connected in series to form a discharge path for discharging, and the secondary battery is pulse-discharged with a constant current based on a command signal issued by the control unit, A step of detecting a voltage of the secondary battery; a step of calculating an internal resistance value of the secondary battery using a difference between the two voltages and a current amount during pulse discharge; and the secondary battery based on the internal resistance value. Diagnosing the degree of deterioration of the battery.

  The portable charger of the present invention is (a) a portable charger capable of storing two or more secondary batteries in a replaceable manner, and individually charging the secondary batteries based on a command signal issued by a control unit. Means for forming a charging path by a plurality of switching elements, (b) means for detecting the voltage of each secondary battery based on a command signal issued by the control unit, and (c) a command signal issued by the control unit In the preliminary charging in which each secondary battery is charged with a current of 0.1 to 0.3 C for a predetermined time based on the voltage, the voltage of each secondary battery during the preliminary charging is detected based on a command signal issued by the control unit (D) calculating a difference between the two voltages, comparing with a preset data table based on the difference between the two voltages, and diagnosing an approximate deterioration degree of each secondary battery; e) based on a command signal issued by the control unit. The secondary batteries accommodated in an exchangeable manner in two or more cells are charged with a constant current while individually monitoring the voltage, and the voltage of the secondary battery is a voltage drop at the time of charging from the maximum value -ΔV is a set value (F) In the secondary battery, there is a secondary battery that is suspected of being deteriorated. A means for connecting the secondary batteries in series on the basis of a command signal issued by the control unit to form a discharge path for discharging by the plurality of switching elements; and (g) based on the command signal issued by the control unit. Means for detecting the voltage of the secondary battery, and (h) based on a command signal issued by the control unit, the secondary battery is pulse-discharged at a constant current, and the voltage of the secondary battery during pulse discharge is determined. Means for detecting, ( i) means for calculating the internal resistance value of the secondary battery using the difference between the two voltages and the current amount during pulse discharge; and (j) comparing the obtained internal resistance value with a preset data table. And means for diagnosing the degree of deterioration of the secondary battery.

Further, the output control is performed by connecting the portable electronic device with output control means that uses the output of the secondary battery as a power source and can set and maintain an output voltage and an output current based on a command signal issued by the control unit. An output terminal capable of supplying the output of the means to the portable electronic device or charging the portable electronic device can be provided.
The portable charger of the present invention preferably further comprises means for notifying the user of the information obtained by the means (d) or (j).

  ADVANTAGE OF THE INVENTION According to this invention, the deterioration diagnostic method of the secondary battery for portable chargers which can diagnose the deterioration of a battery accurately irrespective of the kind of battery can be provided at low cost. In addition, it is possible to provide a portable charger that can safely charge secondary batteries having different degrees of deterioration and different amounts of charged electricity.

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

(Embodiment 1)
In the first embodiment, a means for detecting deterioration of the secondary battery will be described. FIG. 1 is a schematic block diagram showing the configuration of a portable charger in the case of two secondary batteries according to Embodiment 1 of the present invention, and FIG. 2 shows pulse discharge used for a battery management device in the portable charger. FIG. 3 is a schematic block diagram showing the configuration of the means, and FIG. 3 is a schematic block diagram showing the configuration of the series-parallel switching means used in the battery management device in the portable charger. The battery management device 1a is integrated with an assembled battery 2 composed of two secondary batteries housed in a replaceable manner, and constitutes a portable charger 3. The battery pack 2 can be charged by connecting the external device 4 to the input terminal portion Ti.

  The series-parallel switching unit 11 has the configuration shown in FIG. 3 and is composed of charge switch elements SW1 and SW2 and a discharge switch element SW3. The charge switch element SW1 is between the ground and the negative electrode of the secondary battery B1, the charge switch element SW2 is between the charge control means 9 and the positive electrode of the secondary battery B2, and the discharge switch element SW3 is between the secondary battery B1. It is provided between the negative electrode and the positive electrode of the secondary battery B2.

  The control unit 8 detects the output voltages of the assembled battery 2 and the secondary batteries B1 and B2 constituting the battery pack 2 by the battery voltage detection means 5, respectively. Moreover, the control part 8 detects the temperature of the assembled battery 2 and the secondary batteries B1 and B2 which comprise it with the battery temperature detection means 6 and the thermistor 7. FIG. The control unit 8 operates the charge control unit 9 based on the information detected by the battery voltage detection unit 5 and the battery temperature detection unit 6. The control unit 8 issues a command signal to the charge control means 9 to charge the assembled battery 2 with a precharge current (for example, a current of 0.1 to 0.3 C) for a predetermined time and to precharge the battery voltage detection means 5. The battery voltage during pre-charging and pre-charging is detected, and the approximate degree of deterioration is diagnosed based on the difference between the two voltages. After charging the assembled battery 2 to a fully charged state, when the secondary battery suspected of deterioration exists, the control unit 8 issues a command signal to the pulse discharging means 12 to pulse the assembled battery 2 with a constant current. Discharge.

  The constant current discharge circuit of the pulse discharge means 12 has a configuration shown in FIG. 2, for example. The microcomputer 13 has a built-in CMOS, and a constant voltage Vdd is applied to the CMOS input port 13a from the outside. On the other hand, the CMOS output port 13 b is connected to the base of the transistor 14. The positive electrode of the assembled battery 2 composed of a plurality of cells connected in series is connected to the collector of the transistor 14 and the negative electrode is grounded. The emitter of the transistor 14 is grounded via a resistor 15. Assuming that the base voltage of the transistor 14 is Vf and the resistance value of the resistor 15 is R, the current Ic flowing in the direction of the arrow in the figure when the CMOS push-pull port is set to High is obtained by the following Equation 1.

  For example, when Vdd = 5.0V, Vf = 0.7V, and R = 4.3Ω in the above formula, the discharge current Ic can be 1A.

  The control unit 8 issues a command signal to the pulse discharging means 12 to pulse discharge the assembled battery 2 with a constant current as described above, and detect the battery voltages before discharge and during discharge (referred to as Vo and Vpd, respectively). Let The control unit 8 substitutes the obtained battery voltages Vo and Vpd and the discharge current amounts at that time (respectively, Io and Ipd) into the following Equation 2, and calculates the internal resistance Rb of the battery.

Ipd is determined in consideration of the measurement accuracy of the internal resistance Rb and the allowable value of the constant current discharge circuit of the pulse discharge means 12. After calculating Rb, the control unit 8 compares this value with a threshold value Rt recorded in a storage means such as a built-in ROM. If Rb is larger than Rt, the control unit 8 determines that the unit cell has deteriorated. . The threshold value Rt is corrected by taking into account the temperatures of the secondary batteries B1 and B2. The control unit 8 notifies the device user of the obtained information by the notification means 10 as necessary. For the notification means 10, for example, a liquid crystal display or LED that displays information, a speaker that emits a warning sound, a vibrator that emits vibration, or the like is used.

  FIG. 4 is a flowchart for explaining the operation of the portable charger shown in FIG. The procedure of this embodiment will be described in more detail using the flowchart of FIG. First, in step 101, the control unit 8 checks whether or not the external device 4 is connected, and determines whether or not to start the charging operation. If the connection of the external device 4 can be confirmed, the process proceeds to step 102, and the control unit 8 detects the temperatures of the secondary batteries B1 and B2 constituting the assembled battery 2 by the battery temperature detecting means 6 and the thermistor 7, respectively. Thereafter, the process proceeds to step 103, where the control unit 8 detects the output voltages (respectively Vob1 and Vob2) of the secondary batteries B1 and B2 constituting the assembled battery 2 by the battery voltage detection means 5. The control unit 8 proceeds to step 104 based on the information detected by the battery voltage detecting means 5 and the battery temperature detecting means 6, and controls the series / parallel switching means 11 to sequentially switch the contacts to charge the secondary batteries B1 and B2. To do.

  More specifically, first, the charge switch element SW1 is turned on, the charge switch element SW2 is turned off, and the discharge switch element SW3 is turned off (the state of the switch is not shown). (For example, a current of 0.1 to 0.3 C) is supplied, and the secondary battery B1 is charged for a predetermined time (for example, 0.5 seconds). Next, the charging switch element SW1 is turned off and the charging switch element SW2 is turned on (the state of the switch is not shown), and the secondary battery B2 is supplied with a preliminary charging current (for example, 0.1 to 0. 3C), the secondary battery B2 is charged for a predetermined time (for example, 0.5 seconds), the process proceeds to step 105, and the control unit 8 uses the battery voltage detecting means 5 to perform the secondary battery being precharged. The voltages of B1 and B2 (referred to as Vpcb1 and Vpcb2 respectively) are detected. In step 106, the control unit 8 substitutes the obtained battery voltages Vob1, Vob2, Vpcb1, and Vpcb2 into the following formulas 3 and 4, and the voltage difference Vb1 in the secondary battery B1 and the voltage in the secondary battery B2 The difference Vb2 is calculated.

  After calculating Vb1 and Vb2, the control unit 8 compares this value with a threshold value Vt recorded in a storage means such as a built-in ROM. If Vb1 is greater than Vt, the secondary battery B1 Is larger than Vt, it is determined that the secondary battery B2 has deteriorated. The threshold value Vt is corrected by taking into account the temperatures of the secondary batteries B1 and B2.

As a method for diagnosing deterioration of a battery used in a battery management apparatus, a method for determining deterioration of a battery based on the internal resistance of the battery is common. A deteriorated battery has high internal resistance. Therefore, in this method, a DC voltage is applied to the battery, its internal resistance is measured, and the deterioration of the battery is determined based on the magnitude of the obtained value. However, if voltage application means is provided in the battery management device for deterioration diagnosis, the equipment becomes large, and it is difficult to integrate the battery management device and the battery as a battery pack. Therefore, as a battery deterioration diagnosis method suitable for use in a battery pack, a method for detecting a battery voltage during trickle charging has been proposed. Since the deteriorated battery has an increased internal resistance as described above, the voltage becomes higher than that of a normal battery even in trickle charging of about 1 / 20C. The portable charger of the present invention is deteriorated when the assembled battery is charged with a preliminary charging current (for example, a current of 0.1 to 0.3 C) for a predetermined time and the voltage during charging becomes higher than a specified value. Judgment. Normally, the voltage value when the battery capacity is reduced to 50% of the nominal capacity is used as the specified value.

  According to this method, it is not necessary to provide a voltage application means for deterioration diagnosis. Therefore, the system can be greatly reduced in size as compared with the method of measuring the internal resistance by applying a voltage to the battery by the separately provided voltage applying means as described above.

  This method has poor accuracy in deterioration diagnosis and can only make rough judgments, but it can be made inexpensively and quickly, and avoids passing a large current to a secondary battery whose deterioration state has not been determined regardless of whether it is charged or discharged. be able to.

  If there is no suspicion of deterioration of either the secondary battery B1 or B2, in steps 107 and 108, the charge switch element SW1 and the charge switch element SW2 are alternately switched at predetermined intervals (for example, 0.5 seconds) (The state is not shown), and the control unit 8 performs constant current charging while monitoring the voltages of the secondary batteries B1 and B2 by the battery voltage detecting means 5, and either the secondary battery B1 or B2, for example, the secondary battery B1 When the value of -ΔV, which is a voltage drop from the maximum value during charging, exceeds a set value, the charging current is reduced only for the secondary battery B1, and then charging is performed for a predetermined time, and the charging switch element SW1. Is turned off and the charge switch element SW2 is fixed to be turned on (the state of the switch is not shown). The control unit 8 performs constant current charging while monitoring the voltage of the secondary battery B2 being charged by the battery voltage detection means 5, and the voltage of the secondary battery B2 is a voltage drop at the time of charging from the maximum value of −ΔV. When the value exceeds the set value, the charging current is decreased, and charging is further stopped for a predetermined time. This makes it possible to fully charge a secondary battery having different characteristics such as a degree of deterioration of the secondary battery and a difference in remaining capacity. If there is a secondary battery suspected of being deteriorated, in step 109, the control unit 8 notifies the device user of the obtained deterioration information by the notification means 10 as necessary. For the notification means 10, for example, a liquid crystal display or LED that displays information, a speaker that emits a warning sound, a vibrator that emits vibration, or the like is used.

  Next, in steps 110 and 111, the charge switch element SW1 and the charge switch element SW2 are alternately switched at a predetermined interval (for example, 0.5 seconds) (the state of the switch is not shown), and the control unit 8 The constant voltage charging is performed while monitoring the voltage of B1 and B2 by the battery voltage detecting means 5, and the voltage of either the secondary battery B1 or B2, for example, the secondary battery B1 is a voltage drop at the time of charging from the maximum value -ΔV When the value exceeds the set value, only the secondary battery B1 is reduced in charging current, and then charged for a predetermined time to turn off the charge switch element SW1 and fix the charge switch element SW2 on (switch of the switch). (The state is not shown). The control unit 8 performs constant current charging while monitoring the voltage of the secondary battery B2 being charged by the battery voltage detection means 5, and the voltage of the secondary battery B2 is a voltage drop at the time of charging from the maximum value of −ΔV. When the value exceeds the set value, the charging current is decreased, and charging is further stopped for a predetermined time. This makes it possible to fully charge a secondary battery having different characteristics such as a degree of deterioration of the secondary battery and a difference in remaining capacity.

Next, in step 112, the charge switch elements SW1 and SW2 are always turned off, the discharge switch element SW3 is turned on, and the secondary batteries B1 and B2 are connected in series. (The state of the switch is not shown) Further, the process proceeds to step 113, where the control unit 8 detects the temperatures of the secondary batteries B1 and B2 constituting the assembled battery 2 by the battery temperature detecting means 6 and the thermistor 7, respectively. In step 114, the control unit 8 detects the output voltages (respectively Vopd1 and Vopd2) of the secondary batteries B1 and B2 constituting the assembled battery 2 by the battery voltage detecting means 5, and discharges at that time. The amount of electricity Io is detected. Further, the control unit 8 proceeds to step 115 based on the information detected by the voltage detection unit 5 and the battery temperature detection unit 6, and the control unit 8 issues a command signal to the pulse discharge unit 12 to generate the secondary battery B1. And B2 are pulse-discharged at a constant current, the process proceeds to step 116, and the battery voltage detection means 5 detects the battery voltages during pulse discharge (referred to as Vpdb1 and Vpdb2, respectively). In step 117, the control unit 8 substitutes the obtained battery voltages Vopd 1, Vopd 2 and Vpdb 1, Vpdb 2, and the pulse discharge current amount Ipd into the following formulas 5 and 6, and the secondary battery B 1 internal resistance Rb 1 and the secondary battery B 1 Battery B2 internal resistance Rb2 is calculated.

  Ipd is determined in consideration of the measurement accuracy of the internal resistances Rb1 and Rb2 and the allowable value of the constant current discharge circuit of the pulse discharge means 12. For example, in a nickel metal hydride secondary battery, since the internal resistance is as small as several tens of mΩ per cell, it is necessary to discharge with a large current of about 1 C. In order to detect a stable battery voltage by avoiding a surge that occurs immediately after the start of discharge, it is preferable to measure the voltage after 200 microseconds have elapsed from the start of pulse discharge. In addition, when discharging for a long time, elements such as ion diffusion are mixed in the measurement value in a complicated manner. Therefore, the discharge time is preferably within 10 milliseconds.

  Here, since the discharge time is as short as 10 milliseconds, a transistor 14 having a small allowable loss can be used as the transistor 14 constituting the pulse discharge means 12. Therefore, an inexpensive small battery deterioration diagnosis means can be realized. The internal resistance at the time of constant current discharge as described above can be measured regardless of the battery usage status, that is, at the time of charging, discharging, and standby (including intermittent charging pause time). Degradation diagnosis can be performed whenever necessary.

  After calculating Rb1 and Rb2, the control unit 8 compares this value with a threshold value Rt recorded in a storage means such as a built-in ROM. If Rb1 is larger than Rt, the secondary battery B1 Is larger than Rt, it is determined that the secondary battery B2 has deteriorated. The threshold value Rt is corrected by taking into account the temperatures of the secondary batteries B1 and B2. In step 118, the control unit 8 notifies the device user of the obtained deterioration information by the notification means 10 as necessary. For the notification means 10, for example, a liquid crystal display or LED that displays information, a speaker that emits a warning sound, a vibrator that emits vibration, or the like is used.

As described above, according to the present invention, since a constant current discharge circuit can be obtained with a simple configuration, a small battery deterioration diagnosis unit suitable for a portable charger can be realized. In particular, according to the present invention, since deterioration is determined essentially based on the internal resistance of the secondary battery, a highly accurate deterioration diagnosis can be performed regardless of the type of battery. Therefore, batteries such as nickel / cadmium secondary batteries, nickel / hydrogen secondary batteries, lithium ion secondary batteries, etc., whose deterioration could not be accurately diagnosed by the method of detecting the open circuit voltage of the batteries, are also accurate. Can be diagnosed. In addition, even if it discharges with a large current in order to increase the voltage change to detect and to improve the measurement accuracy, the remaining capacity of the battery is hardly reduced because it is a short-time discharge.

(Embodiment 2)
In the second embodiment, a means for supplying power to the portable electronic device will be described. In addition, the same thing as Embodiment 1 uses the same code | symbol, and abbreviate | omits description. FIG. 5 is a schematic block diagram showing a configuration of a portable charger with an output terminal for portable electronic equipment in the case of two secondary batteries in the second embodiment. The portable charger according to the second embodiment is integrated with the output control means 17 that feeds the output of the assembled battery 2 to the portable electronic device with respect to the portable charger 3 according to the first embodiment, and has an output terminal. It is characterized by constituting a portable charger. In FIG. 5, the assembled battery 2 can connect two cells of a fixed size of single 1, single 2, single 3 or single 4 in series, and the output control means 17 can set the voltage of the assembled battery 2 in the portable electronic device 16. The voltage is controlled to be higher than a voltage necessary for charging a secondary battery (not shown) (for example, 5.0 V). The output control means 17 is connected in series with the output positive terminal To +, and controls the current to the output positive terminal To + to be a constant current (for example, 0.5 A) based on a command signal generated by the control unit 8.

  As a reference example of Embodiments 1 and 2, a secondary battery charge control method will be described. In the charge control function by the battery management device of the reference examples of the first and second embodiments, the open voltage of the secondary battery is detected, and the obtained open voltage is compared with a preset data table to obtain a secondary Estimate the remaining battery capacity. At this time, when the remaining capacity of the secondary battery becomes 95% or less of the full capacity, charging of the secondary battery is started.

  In general, a very high accuracy cannot be expected for estimating the remaining capacity of the battery based on the open circuit voltage. For example, in a lithium ion secondary battery, normally, when the open circuit voltage of the battery is detected and the remaining capacity is estimated to be about 80%, the battery is set to resume charging. The actual remaining capacity varies from 60 to 90%. The causes include the accuracy of the data table for comparison with the detected open circuit voltage and the individual difference of the batteries.

  The data table is created based on data at the time when the battery is actually discharged. Therefore, it is necessary to collect measured data over a long period. Therefore, in order to control to resume charging when the remaining capacity reaches about 80% as in the prior art, it is necessary to collect battery voltage data at a capacity of 80 to 100%. However, in order to respond to a request for shortening the development period, sufficient data collection is not performed and an appropriate data table is often not set. Therefore, in this reference example, in the charging control for estimating the remaining capacity based on the open voltage of the secondary battery, charging of the secondary battery is started when the remaining capacity of the secondary battery becomes 95% or less of the full capacity. . This greatly reduces the time required for a single data collection. That is, data collection with a capacity of 95-100% requires a much shorter period of time than data collection with a capacity of 80-100%.

  Therefore, if the same amount of time as in the past is spent collecting all data, more data can be collected and the accuracy of remaining capacity estimation can be increased. Thereby, overcharge of a battery and insufficient charge can be prevented.

  In addition, when the number of data is increased, it is possible to grasp the performance variation between the batteries and the influence of the usage environment, and it is possible to estimate the remaining capacity with high accuracy in actual use. Furthermore, according to this method, since the remaining capacity of 95% or more is always secured, there is an effect that the output time becomes long.

The battery management device for a portable charger according to the present invention is affected by the degree of deterioration of secondary batteries stored in a replaceable manner, by the degree of deterioration of individual secondary batteries, or by the difference in the amount of charged electricity when assembled. If there is a battery that is suspected of being deteriorated, the degree of deterioration of the secondary battery can be diagnosed more accurately and the degree of deterioration is different. It is useful as a battery management device for a portable charger that can safely charge a battery.

Schematic block diagram showing the configuration of the portable charger according to the first embodiment of the present invention. Schematic block diagram showing the configuration of pulse discharge means used in the battery management device in the portable charger of the first embodiment Schematic block diagram showing the configuration of series-parallel switching means used in the battery management device in the portable charger of the first embodiment Flowchart for explaining the operation of the portable charger of the first embodiment Schematic block diagram showing the configuration of the portable charger according to the second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b Battery management apparatus 2 Assembly battery 3 Portable charger 4 External apparatus 5 Battery voltage detection means 6 Battery temperature detection means 7 Thermistor 8 Control part 9 Charge control means 10 Notification means 11 Serial / parallel switching means 12 Pulse discharge means 13 Micro Computer 13a CMOS input port 13b CMOS output port 14 Transistor 15 Resistor 16 Portable electronic device 17 Output control means B1, B2 Cell SW1, SW2 Charge switch element SW3 Discharge switch element Ti Input terminal Ti + Input positive terminal Ti- Input negative terminal To Output Terminal To + Output positive terminal To- Output negative terminal

Claims (4)

A method for diagnosing the degree of deterioration of a plurality of secondary batteries,
Forming a charging path for charging each of the secondary batteries individually based on a command signal issued by the control unit;
Detecting a voltage of each secondary battery based on a command signal issued by the control unit;
In preliminary charging in which each secondary battery is charged with a current of 0.1 to 0.3 C for a predetermined time based on a command signal issued by the control unit, each of the secondary batteries being pre-charged based on the command signal issued by the control unit Detecting a voltage of the secondary battery;
Calculating a difference between the voltages detected in the two steps, and diagnosing the degree of deterioration of each secondary battery based on the difference between the voltages;
Charging the secondary batteries individually until full charge based on a command signal issued by the control unit;
When there is a secondary battery that is suspected of being deteriorated, a step of connecting the secondary batteries in series based on a command signal issued by the control unit to form a discharge path for discharging, and
Detecting the voltage of the secondary battery during pulse discharge while causing the secondary battery to pulse discharge with a constant current based on a command signal issued by the control unit;
Calculating the internal resistance value of the secondary battery using the voltage difference detected in the two steps and the amount of current during pulse discharge;
And a step of diagnosing the degree of deterioration of the secondary battery based on the internal resistance value. A portable charger capable of storing two or more secondary batteries in a replaceable manner,
Means for forming a charging path for individually charging the secondary battery based on a command signal issued by the control unit by a plurality of switching elements;
Means for detecting the voltage of each secondary battery based on a command signal issued by the control unit;
In preliminary charging in which each secondary battery is charged with a current of 0.1 to 0.3 C for a predetermined time based on a command signal issued by the control unit, each of the secondary batteries being pre-charged based on a command signal issued by the control unit Means for detecting the voltage of the secondary battery;
A means for calculating a difference between the voltages detected by the two means, comparing with a preset data table based on the voltage difference, and diagnosing an approximate deterioration degree of each secondary battery;
Based on a command signal issued by the control unit, the secondary batteries housed in an exchangeable manner in two or more cells are charged with constant current while individually monitoring the voltage, and the voltage of the secondary battery drops from the maximum value when charging. Means for reducing the charging current when the value of -ΔV exceeds a set value and then charging for a predetermined time to stop charging;
In the secondary battery, when at least one secondary battery is suspected of being deteriorated, the plurality of switching paths for discharging the secondary battery connected in series based on a command signal issued by the control unit are switched. Means for forming by an element;
Means for detecting the voltage of the secondary battery based on a command signal issued by the control unit;
Means for detecting the voltage of the secondary battery during pulse discharge while pulse discharging the secondary battery with a constant current based on a command signal issued by the control unit;
Means for calculating an internal resistance value of the secondary battery using a voltage difference detected by the two means and a current amount at the time of pulse discharge;
A portable charger comprising means for comparing the obtained internal resistance value with a preset data table and diagnosing the degree of deterioration of the secondary battery. An output control means capable of setting and maintaining an output voltage and an output current based on a command signal issued by the control unit using the output of the secondary battery as a power source;
The portable charging device according to claim 2, further comprising an output terminal capable of supplying the output of the output control means to the portable electronic device or charging the portable electronic device by connecting the portable electronic device. vessel. 4. The portable charger according to claim 2, further comprising means for notifying a device user of the degree of deterioration of the secondary battery.

Images