JP2008295170A - Charger and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charger capable of charging a plurality of kinds of battery packs at proper constant power and constant voltage at low cost. <P>SOLUTION: The charger 101 identifies the kind of a battery pack 131 on the basis of a voltage unique to the battery pack 131 to be supplied to a terminal 129 for communication (D), and determines a charging power value so that the maximum charging current of the identified battery pack may be the maximum value of the charging current in the constant power charging. Then, trickle charging takes place until the charging voltage of the battery pack reaches a set value 1, and then, the constant power charging starts when the charging voltage reaches the set value 1. After that, the constant power charging takes place until the charging voltage reaches a set value 2. Then, when the charging voltage of the battery pack reaches the set value 2, the constant power charging switches to the constant voltage charging. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a charging device that performs constant power charging and / or constant voltage charging on a battery pack including a secondary battery, and a control method thereof.

  2. Description of the Related Art Conventionally, a charging method for shifting from constant power charging to constant voltage charging as shown in FIG. 8 in an in-vehicle battery charging device has been disclosed (see Patent Document 1).

Further, as shown in FIG. 9, a battery charging device is disclosed in which a microcomputer is mounted on a battery pack and the charging current is changed by obtaining information on the maximum charging current (see Patent Document 2).
JP-A-8-106921 Japanese Patent No. 3508384

  However, the technique disclosed in Patent Document 1 belongs to the technical field of in-vehicle batteries, and there is no description regarding setting change of the charging power value. Therefore, in a situation where a plurality of types of secondary batteries are frequently replaced and charged, there is a problem that appropriate constant power control according to the type of secondary battery cannot be performed.

  Further, in the technique disclosed in Patent Document 2, a circuit becomes complicated due to a system in which a microcomputer is mounted on a battery pack. Further, since the charging current is changed, there is a problem that precise control is difficult and an inexpensive system cannot be configured.

  Furthermore, in recent years, electronic devices have been rapidly reduced in size and cost, and there is an increasing demand for further simplification of the internal circuits of the charging device and the battery pack.

  The present invention has been made in view of the above problems and requirements, and provides a charging device and a control method thereof capable of performing appropriate constant power / constant voltage charging at a low cost for a plurality of types of battery packs. The purpose is to do.

  In order to achieve the above object, a charging device according to the present invention is a charging device for charging a battery pack including a secondary battery, wherein an identification means for identifying a type of the battery pack, and maximum charging of the identified battery pack. Determining means for determining a charging power value so that the current becomes a maximum value of a charging current in constant power charging; and when the charging voltage of the battery pack is equal to or higher than a first set value, the charging power value is determined based on the charging power value. Constant power charging means for performing power charging, and constant voltage charging means for performing charging by switching to constant voltage charging when the charging voltage of the battery pack is equal to or higher than a second set value greater than a first set value. It is characterized by that.

  In order to achieve the above object, the charging device of the present invention is a charging device that charges a battery pack having a secondary battery and a nonvolatile memory, and the maximum charging current of the battery pack read from the nonvolatile memory is constant. A determining means for determining a charging power value so as to be a maximum value of a charging current in power charging, and performing constant power charging based on the charging power value when a charging voltage of the battery pack is equal to or higher than a first set value. Constant power charging means, and constant voltage charging means for performing charging by switching to constant voltage charging when a charging voltage of the battery pack is equal to or higher than a second setting value larger than the first setting value. And

  In order to achieve the above object, a control method for a charging device according to the present invention comprises: an identification step for identifying a type of the battery pack in the control method for a charging device that charges a battery pack including a secondary battery; A determining step of determining a charging power value so that the maximum charging current of the battery pack is the maximum value of the charging current in constant power charging; and the charging power when the charging voltage of the battery pack is equal to or higher than a first set value. A constant power charging step for performing constant power charging based on a value, and a constant voltage for charging by switching to constant voltage charging when the charging voltage of the battery pack is greater than or equal to a second set value greater than a first set value. And a charging step.

  In order to achieve the above object, a method for controlling a charging device according to the present invention provides a method for controlling a charging device that charges a battery pack having a secondary battery and a nonvolatile memory. A determination step of determining a charging power value so that a maximum charging current becomes a maximum value of a charging current in constant power charging, and when the charging voltage of the battery pack is equal to or higher than a first set value, based on the charging power value A constant power charging step for performing constant power charging, and a constant voltage charging step for performing charging by switching to constant voltage charging when the charging voltage of the battery pack is greater than or equal to a second set value greater than the first set value. It is characterized by providing.

  According to the present invention, the charging device identifies the type of the battery pack, and determines the charging power value so that the maximum charging current of the identified battery pack becomes the maximum value of the charging current in constant power charging. Then, trickle charging is performed when the voltage of the battery pack is less than the first setting value, and constant power charging is performed based on the charging power value when the charging voltage of the battery pack is equal to or higher than the first setting value by trickle charging. I do. Then, when the charging voltage of the battery pack is equal to or higher than a second set value larger than the first set value by constant power charging, charging is performed by switching to constant voltage charging. Thereby, appropriate constant power and constant voltage charging can be performed at a low cost for a plurality of types of battery packs.

  According to the present invention, the charging device determines the charging power value so that the maximum charging current of the battery pack read from the nonvolatile memory in the battery pack becomes the maximum value of the charging current in the constant power charging. When the voltage of the battery pack is less than the first set value, trickle charging is performed, and when the charging voltage of the battery pack reaches the first set value by trickle charging, constant power charging is performed based on the charging power value. I do. Then, when the charging voltage of the battery pack reaches a second set value larger than the first set value by constant power charging, the charging is switched to constant voltage charging. As a result, it is possible to obtain information on charging directly from the battery pack, and it is possible to set a more appropriate charging power value according to the type of the battery pack.

  According to the present invention, the battery pack includes a temperature detection element. The charging device detects the temperature of the battery pack by a temperature detection element in the battery pack. When the battery pack is subjected to constant current charging, if no increase in the temperature of the battery pack is detected, constant current charging is performed or charging is terminated. As a result, it is possible to detect a defect in the temperature detecting element in the battery pack, and it is possible to perform constant power charging more safely.

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

[First Embodiment]
FIG. 1 is a block diagram showing an internal configuration of a charging device and a battery pack according to the first embodiment of the present invention.

  The charging device 101 is a charging device that charges the battery pack 131. The battery pack 131 is configured to be detachable from the charging device 101, and stores a secondary battery 141 that can be repeatedly charged. The battery pack 131 is configured to be detachable from an electronic device such as a digital camera or a PDA (Personal Digital Assistant), and functions as a power source of the electronic device.

  In the charging apparatus 101, an AC input unit 102 is connected to an external AC (Alternating Current) power source and receives AC supply from the AC power source. The filter circuit 103 reduces noise included in the AC input from the AC input unit 102. The bridge diode 104 rectifies AC into a half wave. The primary electrolytic capacitor 105 converts the half-wave rectified AC into DC. The transformer 106 is a transformer that transforms DC. The switching control unit 107 stabilizes the secondary output of the transformer 106 based on the signal from the photocoupler 1_108. Photocoupler 1_108 transmits the state of the charging voltage / charging current on the secondary side of transformer 106 to the primary side. The rectifier diode 114 and the rectifier capacitor 115 rectify the output from the transformer 106. 112 is a switch, 113 is a photocoupler 2, and 109 to 111 are resistors.

  The regulator 116 supplies a specified DC to the charge control microcomputer 123 and applies a reference voltage to the operational amplifier 117. The operational amplifier 117 is for feeding back the charging voltage to the battery pack 131. Reference numerals 118 and 119 are resistors provided to feed back the charging voltage to the battery pack 131. 121 is a trickle charge switch, 122 is a quick charge switch, and 120 is a resistor.

  The charge control microcomputer 123 is a control circuit including a nonvolatile RAM (Random Access Memory) and a ROM (Read Only Memory). The charging control microcomputer 123 measures the charging voltage and charging current for the battery pack 131. Reference numeral 124 denotes a current detection resistor for the charging control microcomputer 123 to measure the charging current. 125 and 126 are resistors for the charge control microcomputer 123 to measure the charge voltage.

  The + terminal 127 is in contact with and electrically connected to the + terminal 132 on the battery pack side when the battery pack 131 is attached to the charging device 101. The communication (D) terminal 129 is in contact with and electrically connected to the communication (D) terminal 134 on the battery pack side when the battery pack 131 is attached to the charging device 101. The power supply (B) terminal 128 is in contact with and electrically connected to the power supply (B) terminal 133 on the battery pack side when the battery pack 131 is attached to the charging apparatus 101. The terminal 130 comes into contact with and electrically connects to the terminal 135 on the battery pack side when the battery pack 131 is attached to the charging device 101.

  In the battery pack 131, the battery protection circuit 138 protects the secondary battery cell 141 so as not to be overcharged or overdischarged by monitoring the voltage / current when the battery pack 131 is charged and discharged. The charge protection FET 139 is a switch that cuts off the circuit when an abnormality occurs during charging, and is controlled by the battery protection circuit 138. The discharge protection FET 140 is a switch that cuts off the circuit when an abnormality occurs during discharge, and is controlled by the battery protection circuit 138. The secondary battery cell 141 is composed of a lithium ion secondary battery or the like.

  When AC is input to the AC input unit 102, power is supplied to the transformer 106 via the filter circuit 103, the bridge diode 104, and the primary electrolytic capacitor 105. The secondary output voltage of the transformer 106 is rectified by the rectifier diode 114 and the secondary electrolytic capacitor 115. The charging voltage of the battery pack 131 is set via the resistors 118 and 119 that feed back the battery voltage, the operational amplifier 117 that feeds back the battery voltage, and the photocoupler 1_108.

  Charging of the battery pack 131 is controlled by the charge control microcomputer 123.

  When the battery pack 131 is attached to the charging apparatus 101, a reference voltage is supplied from the power supply (B) terminal 128 to the power supply (B) terminal 133 of the battery pack 131, and a voltage unique to the battery pack 131 is generated by the resistors 136 and 137. It is supplied to the communication (D) terminal 129. As a result, the charging control microcomputer 123 detects the attachment of the battery pack 131 and identifies the type of the battery pack 131 based on the supplied voltage specific to the battery pack. Then, the charge control microcomputer 123 controls the photocoupler 2_113 based on the type of the battery pack 131 to limit the output current on the primary side. A constant power charging value (charging power value) for the battery pack 131 is determined based on the value of the output current limiting resistor.

  The charging control microcomputer 123 measures the charging voltage to the battery pack using the resistors 125 and 126, and detects the charging current based on the potential difference generated at both ends of the current detection resistor 124.

  If the voltage of the battery pack is less than the rapid charging start voltage, the charging control microcomputer 123 turns on the trickle charging switch 121 to start trickle charging. Then, the battery pack is recovered until the charging voltage of the battery pack reaches the rapid charging start voltage (set value 1).

  Next, when the charging voltage of the battery pack reaches the rapid charging start voltage (set value 1), the charging control microcomputer 123 turns on the rapid charging switch 122 to start rapid charging of the battery pack. Thereafter, constant power charging is performed until a preset charging voltage (set value 2) is reached. When the preset charging voltage (set value 2) is reached as charging progresses, constant power charging is performed from constant power charging. The charging is terminated by detecting the rise of the charging voltage and the decrease of the charging current.

  FIG. 2 is a flowchart showing a charging process to the battery pack 131 by the charging device 101.

  When the charging control microcomputer 123 detects the attachment of the battery pack 131 (step S102), the charge control microcomputer 123 identifies the type of the battery pack based on the voltage specific to the battery pack 131 supplied to the communication (D) terminal 129 (step S103).

  Next, the charging control microcomputer 123 determines the charging power value so that the maximum charging current of the battery pack identified in step S103 becomes the maximum value of the current in constant power charging (step S104). Then, trickle charging is started (step S105), and standby is performed until the charging voltage of the battery pack becomes equal to or higher than a preset setting value 1 (step S106).

  Next, the charging control microcomputer 123 stops trickle charging when the charging voltage of the battery pack reaches a set value 1 or more, and starts constant power charging based on the charging power value determined in step S104 (step S107). Further, it waits until the charging voltage of the battery pack becomes a preset value 2 or more (step S108).

  Next, when the charging voltage of the battery pack reaches the set value 2 or more, the charging control microcomputer 123 shifts from constant power charging to constant voltage charging (step S109).

  Next, the charging control microcomputer 123 detects a charging voltage and a charging current for the battery pack (steps S110 and S111). Wait until the charging end condition is satisfied (step S112). When the charging voltage and charging current conditions become the charging end condition, the charging process is ended.

  FIG. 3 is a diagram illustrating an example of charging characteristics of the charging device 101 to the battery pack 131.

  In the illustrated charging characteristics, the vertical axis represents the charging voltage and charging current, and the horizontal axis represents the charging time. 209 is a conventional constant current charging characteristic (dotted line), 210 is a conventional constant voltage charging characteristic (dotted line), 212, 213, and 220 are charging current passing points of the conventional charging apparatus, and 219 and 220 are the charging apparatus of the embodiment. A charging current passing point 224 is a conventional charging voltage characteristic (dotted line). 216 is a constant power charging characteristic (solid line) to which the present invention is applied, 217 is a constant voltage charging characteristic (solid line) to which the present invention is applied, and 222 is a charging voltage characteristic (solid line) to which the present invention is applied.

  When the charging voltage of the battery pack is less than the set value 1, trickle charging is performed (208). Then, when the charging voltage of the battery pack becomes a set value 1 or more, rapid charging is started.

  In the conventional charging device, constant current charging is performed after trickle charging. Thereafter, at the point 213, the charging current starts decreasing, and constant voltage charging is started. Then, the charging current decreases according to the charging characteristics of the battery pack (secondary battery), and the charging ends when the current value decreases to the fully charged set current (point 211).

  On the other hand, in the charging apparatus 101 to which the present invention is applied, the charging power value is determined so that the maximum charging current of the battery pack (secondary battery) becomes the maximum charging current in the constant power charging, and is fixed after trickle charging. Power charging is performed. Then, when the charging voltage rises and the charging voltage of the battery pack reaches the set value 2, a sudden decrease in the charging current starts at point 220, and constant voltage charging is started. Thereafter, the charging current decreases according to the charging characteristics of the battery pack, and the charging is terminated when the current value decreases to the fully charged setting current (point 218). By such constant power control, the charging power amount corresponding to Δ212 / 219/220 is increased with respect to the conventional charging device, and as a result, the charging power amount of □ 213/214/215/220 is increased. The charging time is shortened by the time when the charging power amount becomes equal.

  According to the first embodiment, the type of the battery pack is identified based on the voltage specific to the battery pack 131 supplied to the communication (D) terminal 129, and the maximum charging current of the identified battery pack is constant power charging. The charging power value is determined so as to be the maximum value of the charging current at. Then, trickle charging is performed until the charging voltage of the battery pack reaches the set value 1, and then constant power charging is performed until the charging voltage of the battery pack reaches the setting value 2. When the charging voltage of the battery pack reaches the set value 2, the constant power charging is switched to the constant voltage charging. Thereby, appropriate constant power and constant voltage charging can be performed at a low cost for a plurality of types of battery packs.

[Second Embodiment]
FIG. 4 is a block diagram showing an internal configuration of the charging device and the battery pack according to the second embodiment of the present invention. In addition, about the same component as the said 1st Embodiment, the description is abbreviate | omitted using the same code | symbol.

  The charging device 301 is a charging device that charges the battery pack 331. The battery pack 331 is configured to be detachable from the charging device 301, and stores a secondary battery that can be repeatedly charged. The battery pack 331 is configured to be detachable from an electronic device such as a digital camera or a PDA (Personal Digital Assistant), and functions as a power source of the electronic device.

  The battery pack 331 includes a battery protection circuit 138, a charge protection FET 139, a discharge protection FET 140, a secondary battery cell 141, a positive terminal 132, a negative terminal 135, a communication (D) terminal 353, a temperature (T) terminal 354, and a nonvolatile memory 355. Thermistor 356 is provided.

  The charging device 301 includes an AC input unit 102, a filter circuit 103, a bridge diode 104, a primary electrolytic capacitor 105, a transformer 106, a switching control unit 107, a photocoupler 1_108, a rectifier diode 114, and a rectifier capacitor 115. The charging device 301 includes a switch 112, a photocoupler 2_113, resistors 109 to 111, a regulator 116, an operational amplifier 117, resistors 118, 119, 220, and 350, a trickle charge switch 121, and a quick charge switch 122. Further, the charging device 301 includes a charge control microcomputer 123, a + terminal 127, a − terminal 130, a communication (D) terminal 351, and a temperature (T) terminal 352. The resistor 350 is a resistor for applying a predetermined voltage to the nonvolatile memory 355 in the battery pack 331.

  The charging control microcomputer 123 can measure the charging voltage and charging current to the battery pack 131 and can measure the temperature with the thermistor 356 in the battery pack 131. Further, the charging information is read from the nonvolatile memory 355 in the battery pack 131, and the charging state of the battery pack 131 is determined based on the charging information. Further, the charging control microcomputer 123 accesses the nonvolatile memory 355 to write or update various data.

  When the battery pack 331 is attached to the charging device 301, a voltage is supplied from the resistor 350 to the thermistor 356 in the battery pack 331. The thermistor 356 is a temperature detection element whose resistance value changes with temperature. When the voltage divided by the resistor 350 and the thermistor 356 is supplied to the charge control microcomputer 123, the charge control microcomputer 123 can detect the temperature state of the battery pack 331.

  Further, the charging control microcomputer 123 can detect the attachment of the battery pack 331 by supplying a voltage within a set range via the communication (D) terminal 351. When the charge control microcomputer 123 detects the battery pack 331, communication from the charge control microcomputer 123 to the nonvolatile memory 355 in the battery pack 331 is started, and charging information specific to the battery pack 331 stored in the nonvolatile memory 355 is read. It is. The charging information includes information such as identification information of the battery pack 331 and maximum charging current. Based on this charging information, the charging control microcomputer 123 controls the photocoupler 2_113 to set a constant power charging value (charging power value).

  FIG. 5 is a flowchart showing a charging process to the battery pack 331 by the charging device 301.

  In the second embodiment, the processes in steps S202 and S204 to S212 in FIG. 5 are the same as the processes in steps S102 and S104 to S112 in FIG. 2, and instead of step S103 in FIG. Step S220 is executed. In step S <b> 220, the charge control microcomputer 123 reads charge information from the nonvolatile memory 355 in the battery pack 331.

  When the battery pack 331 is attached (step S202), the charging control microcomputer 123 communicates with the nonvolatile memory 355 in the battery pack 331. Then, the charging information (identification information, maximum charging current, full charge detection current, etc.) stored in the nonvolatile memory 355 is read. Then, the type of the battery pack is identified based on the charging information, and calculation is performed as necessary (step S220). Then, the charging power value is determined so that the maximum charging current of the identified battery pack becomes the maximum value of the charging current in the constant power charging (step S204). In step S207, the charging control microcomputer 123 starts constant power charging based on the charging power value determined in step S204.

  According to the second embodiment, at least the maximum charging current value of the battery pack 331 is read from the nonvolatile memory 355 in the battery pack 331. Then, the charging power value is determined so that the maximum charging current of the battery pack becomes the maximum value of the charging current in constant power charging, trickle charging is performed until the charging voltage of the battery pack reaches the set value 1, and then the battery pack The constant power charging is performed until the charging voltage reaches a set value 2. When the charging voltage of the battery pack reaches the set value 2, the constant power charging is switched to the constant voltage charging. As a result, it is possible to obtain information on charging directly from the battery pack, and it is possible to set a more appropriate charging power value according to the type of the battery pack.

[Third Embodiment]
FIG. 6 is a block diagram showing an internal configuration of the charging device and the battery pack according to the third embodiment of the present invention. In addition, about the same component as the said 1st and 2nd embodiment, the description is abbreviate | omitted using the same code | symbol.

  The charging device 401 is a charging device that charges the battery pack 331. The charging device 401 includes an AC input unit 102, a filter circuit 103, a bridge diode 104, a primary electrolytic capacitor 105, a transformer 106, and a switching control unit 107. The charging device 401 includes a photocoupler 1_108, a rectifier diode 114, a rectifier capacitor 115, a switch 112, a photocoupler 2_113, resistors 109 to 111, a regulator 116, an operational amplifier 117, and resistors 118, 119, 220, and 350. Further, the charging device 301 includes a trickle charge switch 121, a quick charge switch 122, a charge control microcomputer 123, a + terminal 127, a − terminal 130, a communication (D) terminal 351, and a temperature (T) terminal 352. Reference numerals 460 and 461 denote resistors, 462 denotes an operational amplifier, and 463 denotes a switch.

  In charging device 401, constant current values are set by resistors 460 and 461. After the quick charging is started, the switch 463 is closed, the charging current flows through the current detection resistor 124, and the operational amplifier 462 operates so as to stabilize the potential difference generated at both ends of the current detection resistor 124. As a result, by combining with the output of the operational amplifier 117 that performs constant voltage control, constant voltage and constant current control becomes possible.

  The charging device 401 performs constant current charging for a predetermined time. When a temperature rise that generally occurs during charging occurs, the charging device 401 determines that the thermistor 356 is functioning normally, opens the switch 463, and performs constant power control. To start. On the other hand, if a constant current charge is performed for a predetermined time and no temperature increase is observed, it is determined that the thermistor 356 is abnormal, and a measure is taken to terminate the charge or not perform the constant power charge.

  FIG. 7 is a flowchart showing a charging process to the battery pack 331 by the charging device 401.

  The processes in steps S302 and S320, steps S304 to S306, and steps S307 to S312 in FIG. 7 are the same as the processes in steps S202 and S220, steps S204 to S206, and steps S207 to S212 in FIG.

  In step S330, constant current charging is performed. In step S331, a timer is started. In step S332, it is determined whether or not a battery pack temperature increase is detected. If no temperature increase is detected, the process ends abnormally (step S333). On the other hand, when the battery pack temperature rise is not detected, the constant current charging is terminated (step S334).

  First, when the charging voltage of the battery pack becomes equal to or higher than the set value 1 in step S306, constant current charging is started (step S330). Next, the timer is started (step S331), and when the temperature rise that normally occurs when constant current charging is performed during the set time of the timer (YES in step S332), the constant current charging is ended (step S332). S334). And it transfers to step S307 and starts constant power charge.

  On the other hand, if the predetermined temperature rise does not occur during the set time of the timer (NO in step S332), the charging is terminated as abnormal termination (step S333). When the process ends abnormally, display may be performed by an LED (not shown) or a warning sound may be generated.

  The main purpose of the third embodiment is that if the temperature detection element responsible for the protection of the secondary battery does not function normally due to a failure or the like, if charging is continued as it is, there is a risk of overcharging. It is to stop. It is also effective as a safety function when a bad battery (a fixed resistor is used in place of the temperature detecting element) that is often seen in recent years is mounted.

  In this embodiment, as a method of confirming the function of the temperature detection element, a method of performing constant current charging after the start of rapid charging and detecting a temperature rise has been described. However, as a simple method, a constant current circuit is not provided and a constant current circuit is not provided. A method may be used in which power charging is performed for a short time and the temperature is determined during that time.

  According to the third embodiment, the timer is started after the constant current charging is started, and the charging is terminated when the temperature increase is not detected by the thermistor 356 during the set time of the timer. As a result, it is possible to detect a defect in the thermistor 356 built in the battery pack, and it is possible to perform constant power charging more safely.

  In the third embodiment, the charging system including the charging device 401 and the battery pack 331 has been described. However, the charging termination method based on the temperature rise detection described above is applied to the first embodiment. Also good. In that case, instead of the battery pack 331, a battery pack 131 to which only the thermistor 356 is added is applied. Thereby, the effect of 3rd Embodiment can be added to the effect of 1st Embodiment.

  In the first to third embodiments, the form in which the charge control microcomputer 123 performs the charge control has been described. However, the charge control without using the microcomputer is also possible.

  The object of the present invention is achieved by executing the following processing. That is, a storage medium that records a program code of software that realizes the functions of the above-described embodiments is supplied to a system or apparatus, and a computer (or CPU, MPU, etc.) of the system or apparatus is stored in the storage medium. This is the process of reading the code. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code and the storage medium storing the program code constitute the present invention.

  Moreover, the following can be used as a storage medium for supplying the program code. For example, floppy (registered trademark) disk, hard disk, magneto-optical disk, CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD + RW, magnetic tape, nonvolatile memory card, ROM or the like. Alternatively, the program code may be downloaded via a network.

  Further, the present invention includes a case where the function of the above-described embodiment is realized by executing the program code read by the computer. In addition, an OS (operating system) running on the computer performs part or all of the actual processing based on an instruction of the program code, and the functions of the above-described embodiments are realized by the processing. Is also included.

  Furthermore, a case where the functions of the above-described embodiment are realized by the following processing is also included in the present invention. That is, the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing.

It is a block diagram which shows the internal structure of the charging device and battery pack which concern on the 1st Embodiment of this invention. 4 is a flowchart showing a charging process to the battery pack 131 by the charging device 101. 6 is a diagram illustrating an example of charging characteristics of the charging device 101 to the battery pack 131. FIG. It is a block diagram which shows the internal structure of the charging device and battery pack which concern on the 2nd Embodiment of this invention. 5 is a flowchart showing a charging process to a battery pack 331 by a charging device 301. It is a block diagram which shows the internal structure of the charging device and battery pack which concern on the 3rd Embodiment of this invention. 4 is a flowchart showing a charging process to a battery pack 331 by a charging device 401. It is a figure which shows the Example of the conventional charging device. It is a figure which shows the Example of the conventional battery charging device.

Explanation of symbols

101, 301, 401 Charging device 108 Photocoupler 1
113 Photocoupler 2
121 trickle charge switch 122 quick charge switch 123 charge control microcomputer 131,331 battery pack 141 secondary battery cell 136,137 resistor 355 nonvolatile memory 356 thermistor (temperature detection element)

Claims (8)

In a charging device for charging a battery pack including a secondary battery,
Identification means for identifying the type of the battery pack;
Determining means for determining a charging power value so that the maximum charging current of the identified battery pack becomes a maximum value of charging current in constant power charging;
Constant power charging means for performing constant power charging based on the charging power value when a charging voltage of the battery pack is equal to or higher than a first set value;
A charging device, comprising: constant voltage charging means for switching to constant voltage charging and charging when a charging voltage of the battery pack is equal to or higher than a second setting value larger than the first setting value. In a charging device for charging a battery pack having a secondary battery and a nonvolatile memory,
Determining means for determining a charging power value so that a maximum charging current of the battery pack read from the nonvolatile memory becomes a maximum value of a charging current in constant power charging;
Constant power charging means for performing constant power charging based on the charging power value when a charging voltage of the battery pack is equal to or higher than a first set value;
A charging device, comprising: a constant voltage charging unit that performs charging by switching to constant voltage charging when a charging voltage of the battery pack is a second setting value larger than the first setting value.   3. The charging device according to claim 1, further comprising trickle charging means for performing trickle charging when a charging voltage of the battery pack is less than the first set value. The battery pack includes a temperature detection element,
The charging device includes temperature detecting means for detecting the temperature of the battery pack by the temperature detecting element;
Constant current charging means for performing constant current charging on the battery pack;
And a charge control unit configured to perform the constant current charging or terminate the charging when the temperature detection unit does not detect a preset temperature rise at a predetermined time after the start of charging. Item 4. The charging device according to any one of Items 1 to 3. In a control method of a charging device that charges a battery pack including a secondary battery,
An identification step for identifying the type of the battery pack;
A determination step of determining a charging power value so that the maximum charging current of the identified battery pack becomes a maximum value of charging current in constant power charging;
A constant power charging step of performing constant power charging based on the charging power value when a charging voltage of the battery pack is equal to or higher than a first set value;
And a constant voltage charging step of performing charging by switching to constant voltage charging when the charging voltage of the battery pack becomes equal to or higher than a second setting value greater than a first setting value. Method. In a control method of a charging device for charging a battery pack having a secondary battery and a nonvolatile memory,
A determination step of determining a charging power value so that a maximum charging current of the battery pack read from the nonvolatile memory becomes a maximum value of a charging current in constant power charging;
A constant power charging step of performing constant power charging based on the charging power value when a charging voltage of the battery pack is equal to or higher than a first set value;
And a constant voltage charging step of performing charging by switching to constant voltage charging when a charging voltage of the battery pack becomes equal to or higher than a second setting value larger than the first setting value. Control method.   7. The method of controlling a charging device according to claim 5, further comprising a trickle charging step of performing trickle charging when a charging voltage of the battery pack does not satisfy the first set value. A temperature detection step of detecting the temperature of the battery pack by a temperature detection element provided in the battery pack;
A constant current charging step for performing constant current charging on the battery pack;
A charge control step of performing the constant current charging or terminating the charging when the temperature detection step does not detect a preset temperature rise at a predetermined time after the start of charging. Item 8. The charging device control method according to any one of Items 5 to 7.

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