WO2014050152A1

WO2014050152A1 - Battery charger and battery pack

Info

Publication number: WO2014050152A1
Application number: PCT/JP2013/005825
Authority: WO
Inventors: Takao Aradachi; Shinji Watanabe; Kazuhiko Funabashi; Yuki Horie
Original assignee: Hitachi Koki Co., Ltd.
Priority date: 2012-09-28
Filing date: 2013-09-30
Publication date: 2014-04-03

Abstract

A battery pack configured to be connectable to a power tool includes a secondary battery cell configured to be charged by a charging device; and control means for controlling charging the secondary battery cell. The control means includes signal output means for outputting a signal indicating information related to the secondary battery cell to the charging device, the signal output means being configured to output a pulsed signal indicating a charging condition for the secondary battery cell to the charging device.

Description

BATTERY CHARGER AND BATTERY PACK

The invention relates to a battery pack and a battery charger.

As a power source for a cordless power tool, a battery pack with a built-in battery set is used. In a battery charger for charging this type of battery pack, a terminal corresponding to a terminal provided at the battery pack is provided. An analog signal indicative of information of a secondary battery built in the battery pack is acquired at the battery charger side via these terminals, and charging control of the secondary battery is performed based on the analog signal.

Currently, lithium-ion cells are the main stream of secondary battery cells that are built in a battery pack of a power tool. There is a plurality of kinds of secondary battery cells such as secondary battery cells having nickel-series positive electrode, or the like. Further, among battery packs using the same kind, for example, lithium-ion battery cells, there are types having a plurality of output voltages depending on the usage of the tool. The battery capacity also ranges widely from several Ah to several dozen Ah. Further, with diversification of battery cell specification, for the same type of battery pack belonging to the same outputs voltage standard, there is a plurality of kinds of charging voltages for charging secondary battery cells.

However, the number and the roll of terminals provided at both the conventional battery charger and the battery pack are fixed and restricted, and hence only limited battery information such as the number of cells constituting the battery set, battery temperature, etc. is provided from the battery pack to the battery charger. Thus, based only on limited battery information such as the number of cells and the battery temperature, the battery charger can provide only generally appropriate charging function for various battery packs, or proper preferable charging function for specific battery packs of which the conditions are preliminarily set. That is, it has been difficult to perform precise charging control in consideration of individual characteristics of a wide variety of secondary batteries.

A wide variety of kinds (voltage, battery capacity, battery type, etc.) of battery packs for cordless power tools are provided so as to correspond to a variety of power tools. Due to requirements of high power, a use of a long period of time, etc., lithium-ion batteries are the mainstream of built-in battery cells. However, battery packs using other kinds of battery cells such as a secondary battery of a nickel-series positive electrode are still used in larger numbers. On the other hand, from standpoints of users, there is an increasing demand of a common battery charger for the wide variety of battery pack. Hence, in order to perform optimum charging for batteries having various numbers of cells and various connection configurations with a single battery charger, a method has been proposed so far in which the kind of the battery cell is determined and, depending on the determination result, an optimum charging control set preliminarily for the battery charger is selected.

In the above-described battery charger, however, charging control methods are preset for connected batteries in a one-to-one correspondence. Hence, for example, if a battery suitable for a charging condition different from the controls preset in the battery charger is newly developed, there has been a problem that charging cannot be performed with an optimum condition for the battery. Accordingly, conventionally, every time a new battery is developed, a battery charger having the charging condition of the new battery needs to be additionally developed for performing optimum charging for the battery.

Japanese Patent Application Publication No. 2009-178012

In view of the foregoing, it is an object of the invention to provide a battery pack which transmits battery information as a pulsed signal to a charger in order to charge the battery pack.

It is another object of the invention to provide a charging device which establishes digital communication with the battery pack in order to charge the same.

It is a further object of the invention to provide a charging system, a battery pack, and a battery charger capable of performing more suitable charging control using a connection terminal provided between an existing battery charger and a battery pack.

it is a further object of the invention to provide a battery pack (hereinafter referred to as "digital type of battery pack") having the same number of terminals and the same terminal arrangement as conventional battery pack (hereinafter referred to as "existing battery pack" or "analog type of battery pack") and configured to send more information to the battery charger side by digitalization. It is also an object of the invention to provide a battery charger capable of determining which of the existing battery pack and the digital type of battery pack is mounted, and capable of performing appropriate charging depending on the mounted battery pack regardless of which battery pack is mounted.

The present invention further provides a battery pack configured to be connectable to a power tool, comprising: a secondary battery cell configured to be charged by a charging device; control means for controlling charging the secondary battery cell; and signal output means for outputting a signal indicating information related to the secondary battery cell to the charging device, wherein the control means causes the signal output means to output a pulsed signal indicating a charging condition for the secondary battery cell to the charging device.

According to the above-described configuration, when the battery pack is mounted on the battery charger, the controller outputs the charging conditions of the secondary battery to the battery charger, as a pulsed signal, via the signal output means for outputting the signal indicative of information of the secondary battery. Based on the inputted pulse signal, the battery charger sets charging conditions of the secondary battery such as the charging voltage, the charging current, the final current, etc. to perform charging of the secondary battery in the battery pack. The battery pack itself provides the battery charger with the charging conditions of the secondary battery as the pulse signal. Thus, the battery charger can charge the battery pack based on the inputted information, and a dedicated charging program need not be provided beforehand. Accordingly, the battery pack is charged without using a dedicated battery charger for the battery pack.

Further, the pulse signal indicative of information of charging conditions of the secondary battery is transmitted to the battery charger, by using signal output means provided in most battery packs for outputting signals indicative of information of the secondary battery. Thus, dedicated output lines need not be provided, and the battery pack can be made in a compact configuration.

Preferably, the signal indicating the information related to the secondary battery cell comprises a type of battery cell, a number of the battery cells, and connecting configuration of the battery cells included in the secondary battery cell, wherein the charging condition for the secondary battery cell comprises at least one of a charging method, a charging voltage, a charging current, a charging time-period, and a final current for charging the secondary battery cell, a charging capacity, history information of charge and discharge, a condition of preliminary charge.

With this configuration, the pulse signal indicative of charging conditions of the secondary battery can be sent to the battery charger, by using signal output means provided in most battery packs for outputting signals indicative of the kind, the number of battery cells constituting the secondary battery, and the connection configuration. Thus, dedicated signal output means need not be provided for outputting the pulse signal, and the battery pack can be made in a small and compact configuration.

Preferably, the signal output means outputs the signal through a terminal connected to at least one of a battery-type identifying element, a temperature detecting element, and full-charge detecting element included in the battery pack. With this configuration, the signal can be transmitted from the battery pack to the battery charger by using existing signal lines.

The present invention provides a battery pack, comprising: a secondary battery cell configured to be charged by a charger; battery-side connecting means for connecting to a charger-side connecting means included in the charger; first information generating means for generating an analog signal indicating first battery information related to the secondary battery cell; second information generating means for generating a digital signal indicating second battery information related to the secondary battery cell; charger determination means for determining a type of the charger connected through the charger-side connecting means; selecting and connecting means for selecting the second information generating means and connecting the second information generating means to the battery-side connecting means when the charger determination means determines that the charger is a digital type.

The battery pack can be connected to the digital type of battery charger for charging, and can be charged under precise control while referring to first battery information as well as second battery information. Further, the battery pack can be charged by using an analog type of battery charger as before.

Preferably, the selecting and connecting means connects the first information generating means to the battery-side connecting means when the charger-side connecting means is connected to the battery-side connecting means.

At the time of connection, it is unknown whether the battery charger to which the battery pack is connected is the digital type or the analog. Hence, immediately after connection, an analog signal indicative of first battery information relating to a secondary battery is transmitted to the battery charger, so that information relating to the battery pack to be charged can be obtained whichever the type of the battery charger is.

Preferably, the battery pack further comprises battery pack type information transmitting means for transmitting to the charger that the battery pack connected to the charger is a digital type.

According to this configuration, the battery charger can recognize the type of the battery pack to be charged.

Preferably, the first information generating means comprises: analog temperature signal generating means for detecting a temperature of the secondary battery cell and generating an analog temperature signal indicating the detected temperature of the secondary battery cell; analog battery cell number generating means for generating analog battery cell number signal indicating a number of battery cells included in the secondary battery cell, wherein the battery-side connecting means comprises: a first terminal configured to output the analog temperature signal generated by the analog temperature signal generating means; and a second terminal configured to output the analog battery cell number signal generated by analog battery cell number generating means.

The digital type of battery pack also has the same configuration of the analog type of battery pack, so that a compatible use is possible.

Preferably, the second information generating means is connected to the second terminal.

An existing second terminal is used to send a digital signal from the second information generating means unique to the digital type of battery pack to the battery charger. Thus, no new terminal needs to be provided.

The present invention further provides a charging system comprising: a battery pack detachably connected to a power tool, and a charging device configured to charge the battery pack, characterized in that the battery pack comprises: a secondary battery cell configured to be charged by the charging device; battery pack control means for controlling charging the secondary battery cell; and signal output means for generating a signal indicating information related to the secondary battery cell, wherein the battery pack control means causes the signal output means to generate and output a pulsed signal indicating a charging condition for the secondary battery cell, and the charging device comprises: signal input means configured to connected to the signal output means; and charging device control means for controlling charging the battery pack, wherein the charging device control means determines the charging condition on the basis of the pulsed signal received by the signal input means and charges the secondary battery cell.

According to the above-described configuration, when the battery pack is mounted on the battery charger, the battery pack outputs the pulse signal indicative of the charging condition of the secondary battery to the battery charger via the signal output means for outputting the signal indicative of information of the secondary battery. On the other hand, based on the inputted pulsed signal, the battery charger sets charging conditions of the secondary battery such as a charging voltage, a charging current, and a final current, etc. to perform charging of the secondary battery. The charging conditions of the battery pack are supplied from the battery pack to the battery charger at the time of connection. Thus, the battery charger can charge the battery pack based on the inputted information, and a dedicated charging program specific to each battery pack need not be provided beforehand. Further, because the battery pack provides the mounted battery charger with its own charging information, the battery pack is charged with the charging conditions suitable for the battery pack, without using a dedicated battery charger.

Preferably, the signal indicating the information related to the secondary battery cell comprises a type of battery cell, a number of the battery cells, and connecting configuration of the battery cells included in the secondary battery cell, wherein the charging condition for the secondary battery cell comprises at least one of a charging method, a charging voltage, a charging current, a charging time-period, and a final current for charging the secondary battery cell, a charging capacity, history information of charge and discharge, and a condition of preliminary charge. Here, "preliminary charge" is charging control means for performing preliminary charging with conditions of small output of voltage, current, etc., and performing main charging with conditions suitable for the secondary battery based on the result of the preliminary charging.

With this configuration, the pulse signal indicative of charging conditions of the secondary battery can be sent from the battery pack to the battery charger, by using signal output means provided in most battery packs for outputting signals indicative of the kind, the number of battery cells constituting the secondary battery, and the connection configuration and by using signal input means provided in the battery charger for receiving the signals. Thus, dedicated means need not be provided for sending and receiving the pulse signal, and the battery pack and the battery charger can be made in small and compact configurations.

Preferably, the signal output means and the signal input means treat the signal through a terminal connected to at least one of a battery-type identifying element, a temperature detecting element, and fully-charge detecting element included in the battery pack. With this configuration, the signal can be exchanged between the battery pack and the battery charger by using existing signal lines.

The present invention further provides a charging device comprising: control means for charging a battery pack comprising a secondary battery cell and a terminal connectable with a power tool; and signal input means for receiving a signal indicating information related to the secondary battery cell, wherein the signal input means receives a pulsed signal indicating a charging condition for charging the battery pack, the charging condition being generated in the battery pack, and the control means is configured to charge the secondary battery cell on the basis of the received charging condition.

According to the above-described configuration, the battery charger receives charging conditions of the battery pack such as the charging voltage, the charging current, etc., as pulse signals, from the mounted battery pack via the signal output section. And, the battery charger sets the charging voltage, the charging current, etc. based on the charging conditions, to perform charging of the battery pack. Accordingly, the battery charger does not need to have a preset charging program, and can perform optimum charging for the mounted battery pack as appropriate. Further, the battery charger can charge battery packs of various specifications.

Preferably, the signal indicating the information related to the secondary battery cell comprises a type of battery cell, a number of the battery cells, and connecting configuration of the battery cells included in the secondary battery cell, wherein the control means is configured to set at least one of a charging method, a charging voltage, a charging current, a charging time-period, and a final current for charging the secondary battery cell, a charging capacity, history information of charge and discharge, and a condition of preliminary charge as the charging condition on the basis of the type of battery cell, the number of the battery cells, and connecting configuration, and then charge the secondary battery cell.

With this configuration, the pulsed signal indicative of charging conditions of the secondary battery can be received from the battery pack, by using signal input means (terminal) to which signals indicative of the kind, the number of battery cells constituting the secondary battery and the connection configuration are inputted, the signal input means being conventionally provided in battery chargers. Hence, dedicated signal input means need not to be provided for inputting the charging conditions, and the battery charger can be made in a small and compact configuration.

Preferably, the signal input means receives the signal through a terminal connected to at least one of a battery-type identifying element, a temperature detecting element, and fully-charge detecting element included in the battery pack.

The present invention further provides a charging device for selectively charging one of a digital type of battery pack configured to generate a digital signal indicating battery information related to a secondary battery cell therein and an analog type of battery pack configured to respond only to analog signal, comprising: charger-side connecting means connectable to a battery-side connecting means included in the battery pack; battery pack determination means for determining whether the battery pack connected to the charger-side connecting means is the digital type or the analog type; and control means for control charging the secondary battery cell included in the battery pack connected to the charger-side connecting means in accordance with the analog signal or the digital signal transmitted through the battery-side connecting means from the connected battery pack.

The battery charger can charge both of the digital and analog types of battery pack. The battery charger determines which type the battery pack is, and then performs appropriate charging control based on the determination result.

Preferably, the control means includes an analog to digital converting function for converting the analog signal transmitted through the battery-side connecting means to a digital signal.

Even when the analog type of battery is charged, the control means performs charging control after converting the provided analog signal into a digital signal.

Preferably, the control means establishes digital communication to receive a digital signal from information generating means included in the connected digital type of battery pack when the digital type of battery pack is connected to the charger-side connecting means.

Digital communication can be performed between the digital type of battery pack and the digital type of battery charger. Hence, more detailed information relating to the battery pack to be charged can be transmitted efficiently to the battery charger side.

Preferably, the control means establishes analog communication to receive an analog signal from information generating means included in the analog type of battery pack when the analog type of battery pack is connected to the charger-side connecting means.

Even when the analog type of battery pack is connected to the digital type of battery charger, charging can be performed as before. Thus, a compatible battery charger is provided.

According to the invention, while supporting a conventional charging control function for the analog type of battery pack, and, for the digital type of battery pack, more detailed battery information is transmitted to the digital type of battery charger through digital communication. Based on the transmitted battery information, the digital type of battery charger can perform more precise charging control.

Fig. 1 is a circuit diagram showing a charging device and a battery pack according to the first embodiment of the present invention. Fig. 2 is a block diagram and a flowchart showing the charging device and the battery pack according to the first embodiment of the present invention. Fig. 3 is a circuit diagram showing a charging device and a battery pack according to the second embodiment of the present invention. Fig. 4 is a time-chart showing pulsed signals transmitted from the battery pack to the charging device when the charging device of Fig. 3 charges the battery pack.

Hereinafter, a first embodiment of the invention will be described while referring to Figs. 1 and 2.

Fig. 1 shows a charging system 1 according to the embodiment of the invention. The charging system 1 includes a battery pack 10 and a battery charger 100 for charging the battery pack 10. The battery charger 100 of the embodiment (hereinafter also referred to as "digital-supported-type battery charger") is configured to charge both of an existing battery pack for which charging control can be performed in an analog method, and a battery pack of the embodiment for which charging control can be performed in a digital method (hereinafter also referred to as "digital-supported-type battery pack"). Accordingly, there are three charging patterns of charging the existing battery pack with the digital-supported-type battery charger, charging a digital-supported-type battery pack with the digital-supported-type battery charger, and charging a digital-supported-type battery pack with the existing battery charger for charging the existing battery pack. Of these, Fig. 1 shows a case of charging the digital-supported-type battery pack with the digital-supported-type battery charger.

As shown in Fig. 1, the battery pack 10 includes, within a main body, a battery set 11, a protection IC 12, a regulator 13, a thermistor 14 which is a thermosensor, a battery-type identifying element 15, a microcomputer (hereinafter, referred to as "battery-side microcomputer") 16, a fully-charge signal inputting section 17, a short circuit 18, and a switch circuit (hereinafter, referred to as "battery-side switch circuit") 19.

The battery set 11 is specified by a battery type (a lithium-ion battery, a nickel-cadmium battery, etc.), the number of battery cells constituting the battery set 11, and a connection configuration. So, there is a wide variety of battery sets. For example, the battery set may be four lithium-ion batteries connected in series (the battery voltage in this case is 14.4 V), or five lithium-ion batteries connected in series (the battery voltage in this case is 18 V). Or, the battery set may be configured by providing a plurality of blocks ("b" blocks, "b" is a natural number) of a plurality of battery cells ("a" battery cells, "a" is a natural number) connected in series, and connecting battery cells corresponding to the "b" blocks with one another, thereby connecting "b" series-connected blocks in parallel, each of the "b" series-connected blocks including "a" battery cells.

The switch circuit 19 provided in the battery pack 10 (hereinafter, referred to as "battery-pack-side switch circuit 19") includes a first switch section and a second switch section. The first switch section includes a first switch SW1 and a second switch SW2. One end of the first switch SW1 is connected to the thermistor 14, and the other end of the first switch SW1 is connected to an LS terminal. One end of the second switch SW2 is connected to an input terminal of the microcomputer 16 (hereinafter, referred to as "battery-side microcomputer 16"), and the other end of the second switch SW2 is connected to the LS terminal. The second switch section includes a third switch SW3 and a fourth switch SW4. One end of the third switch SW3 is connected to the battery-type identifying element 15, and the other end of the third switch SW3 is connected to a T terminal. One end of the fourth switch SW4 is connected to the input terminal of the battery-side microcomputer 16, and the other end of the fourth switch SW4 is connected to the T terminal. The first switch SW1 and the second switch SW2 of the first switch section is tuned ON/OFF in a complementary manner. That is, when the first switch SW1 is ON, the second switch SW2 is OFF. Or, when the first switch SW1 is OFF, the second switch SW2 is ON. Similarly, the third switch SW3 and the fourth switch SW4 of the second switch section is turned ON/OFF in a complementary manner.

Immediately after the battery pack 10 is mounted on the battery charger 100, the first switch SW1 constituting the first switch section is ON, and the second switch SW2 is OFF, and the third switch SW3 constituting the second switch section is ON, and the fourth switch SW4 is OFF.

The thermistor 14 is disposed in contact with or adjacent to the battery set 11, and resistance value of the thermistor 14 changes in accordance with temperature of the battery set 11. When the battery pack 10 is mounted on the battery charger 100, one end of the thermistor 14 is connected to the LS terminal via the first switch SW1 of the battery-side switch circuit 19, and the thermistor 14 outputs an analog signal indicative of battery temperature to the battery charger 100. If the first switch SW1 of the battery-side switch circuit 19 is ON and the second switch SW2 is OFF, the thermistor 14 is connected to the LS terminal. This connection state corresponds to a state in which a thermistor provided in an existing battery pack is connected to the LS terminal.

The protection IC 12 monitors voltage of each battery cell, and outputs a fully-charge signal when the protection IC 12 determines that at least one of the battery cells is overvoltage. This fully-charge signal is inputted to the fully-charge signal inputting section 17. If the first switch SW1 of the battery-side switch circuit 19 is ON and the second switch SW2 is OFF, the fully-charge signal inputting section 17 is connected to the LS terminal. This connection state corresponds to a state in which a fully-charge signal inputting section provided in the existing battery pack is connected to the LS terminal. The fully-charge signal inputting section 17 to which the fully-charge signal is inputted outputs an abnormal signal to the LS terminal. The abnormal signal is an analog signal indicating that the battery set 11 is in a fully-charged state, and this analog signal is sent to the battery charger 100 via the LS terminal.

The battery-type identifying element 15 is a resistive element having an inherent resistance value depending on the battery type of the battery set 11, the number of cells, and its connection configuration. When the battery pack 10 is mounted on the battery charger 100, one end of the battery-type identifying element 15 is electrically connected to the battery charger 100 via the third switch SW3 and the T terminal. The battery charger 100 detects the resistance value of the battery-type identifying element 15, thereby identifying the battery set 11 built in the mounted battery pack. A state in which the third switch SW3 of the battery-side switch circuit 19 is ON and the fourth switch SW4 is OFF corresponds to a state in which a battery-type identifying element provided in the existing battery pack is connected to the T terminal.

The regulator 13 is connected to the battery set 11. The regulator 13 generates a predetermined driving voltage using the battery set 11 as the power source, and applies the generated driving voltage to the battery-side microcomputer 16.

The short circuit 18 is connected to between an ungrounded side terminal of the battery-type identifying element 15 and an output terminal of the battery-side microcomputer 16. The specific circuit configuration of the short circuit 18 is shown in Fig. 2, and includes a grounded-emitter transistor 181, a base resistance, and a bias resistance. Specifically, the base of the transistor 181 is connected to the output terminal of the battery-side microcomputer 16 via the base resistance. The bias resistance is connected to between the base and the emitter.

The battery-side microcomputer 16 starts up upon supply of driving voltage from the regulator 13, and performs a predetermined process based on various input information. The battery-side microcomputer 16 is provided with an output terminal connected to the short circuit 18 as well as output terminals connected to the second switch SW2 and the fourth switch SW4 of the battery-pack-side switch circuit 19.

The battery-side microcomputer 16 internally includes a memory (not shown). The memory stores the charging method of the battery pack 10, charging voltage, charging current, a charging time period, a final current, charging capacity, history information of charge and discharge, conditions of preliminary charge, and the like, as charging conditions of the battery pack 10. These charging conditions are sent to the battery charger 100 via a first line path through the second switch SW2 of the battery-pack-side switch circuit 19 and the LS terminal and via a second line path through the fourth switch SW4 and the T terminal.

Next, the digital-supported-type battery charger 100 will be described. The battery charger 100 includes a primary-side rectifier circuit 20, a main power-source circuit 30, a transformer 40, a secondary-side rectifier circuit 50, a current controlling and setting circuit 60, a battery voltage detecting circuit 70, a voltage controlling and setting circuit 80, a feedback switching circuit 90, a constant-voltage power source circuit 110, a battery-type determining circuit 120, a battery temperature and overcurrent detecting circuit 130, a microcomputer 140 (hereinafter referred to as "charger-side microcomputer 140"), a display section 150, and a regulator 160.

The primary-side rectifier circuit 20 rectifies AC power supplied from an AC power source 21, and outputs the rectified power.

The main power-source circuit 30 includes a switching IC 31, an FET 32, and a latch circuit 33. The main power-source circuit 30 adjusts output power to the primary-side of the transformer 40 based on PWM control by the switching IC 31 and the FET 32. The latch circuit 33 forcefully terminates charging of the battery pack 10, with a signal outputted from the charger-side microcomputer 140 via a coupler 134.

The secondary-side rectifier circuit 50 rectifies pulse power outputted from the secondary-side of the transformer 40, and supplies the rectified power to the battery pack 10.

The current controlling and setting circuit 60 sets charging current of the battery pack 10 in accordance with a signal from the charger-side microcomputer 140 and detects charging current flowing through the battery pack 10, and also outputs a corresponding signal to the feedback switching circuit 90 based on the detected charging current.

The battery voltage detecting circuit 70 detects charging voltage of the battery pack 10.

The voltage controlling and setting circuit 80 controls charging voltage of the battery pack 10, in cooperation with a potentiometer 81. The voltage controlling and setting circuit 80 sets the charging voltage in accordance with a signal from the charger-side microcomputer 140, and outputs a corresponding signal to the feedback switching circuit 90.

The feedback switching circuit 90 outputs a signal to the main power-source circuit 30 via a coupler 91 based on output signals of the current controlling and setting circuit 60 and the voltage controlling and setting circuit 80, so that the charging voltage and the charging current of the battery pack 10 are target values.

The constant-voltage power source circuit 110 includes a subsidiary power source 111, a transformer 112,

power sources

113 and 114, a fan 115, and a regulator 116. The constant-voltage power source circuit 110 generates a DC voltage Vcc from voltage outputted from the primary-side rectifier circuit 20, and supplies the DC voltage Vcc to the charger-side microcomputer 140. The constant-voltage power source circuit 110 ends operations based on a signal sent from the charger-side microcomputer 140 via a coupler 117.

The battery-type determining circuit 120 includes a resistive element 121 having a predetermined resistance value. When the battery pack 10 is mounted, the resistive element 121 is connected to the battery-type identifying element 15 provided at the battery pack 10 side via the T terminal, and the resistance value of the battery-type identifying element 15, i.e., an analog signal indicative of the type of the secondary battery 11 is inputted to an A/D input port of the charger-side microcomputer 140. Note that a transistor 181 constituting the short circuit 180 is OFF.

The battery temperature and overcurrent detecting circuit 130 includes a battery temperature detecting circuit and a fully-charge detecting circuit. The battery temperature detecting circuit 131 inputs, to the charger-side microcomputer 140, a temperature signal corresponding to temperature of the battery pack 10 based on the resistance value of the thermistor 14. And, if a fully-charge signal is outputted from the battery pack 10, the battery temperature detecting circuit 131 inputs the fully-charge signal to the charger-side microcomputer 140.

The display section 150 includes an LED, and is connected to the charger-side microcomputer 140. The display section 150 displays an unmounted state, a charging state, or a charge completed state of a battery pack, by changing the emitting color of the LED.

First, the charger-side microcomputer 140 determines the type of secondary battery, the number of cells, and the connection configuration of the battery pack 10 based on a signal inputted from the battery-type determining circuit 120, and outputs a charge start signal to the main power-source circuit 30. Further, the charger-side microcomputer 140 outputs a signal corresponding to charging conditions such as a charging capacity, a charging voltage, an allowable current, a final current, etc. represented by pulse signals from the battery pack 10 described later to the current controlling and setting circuit 60 and the voltage controlling and setting circuit 80. Further, when the battery temperature and overcurrent detecting circuit 130 detects charge abnormality of the battery pack 10, the charger-side microcomputer 140 forcefully stops charging of the battery pack 10. In some embodiments, the charger-side microcomputer 140 measures the charging time, and stops charging of the battery pack 10 after an elapse of a predetermined time.

The regulator 160 generates driving voltage of the battery-side microcomputer 16 (for example, 5V) with the power source voltage of 12V, and applies the driving voltage to the battery-side microcomputer 16 via a V terminal.

The battery charger 100 includes the regulator 160 that switches ON/OFF of power supply to the battery-side microcomputer 16 of the mounted battery pack 10. The regulator 160 becomes ON when the battery pack 10 is mounted. Upon becoming ON, the regulator 160 applies the DC voltage Vcc, that is, 5V to the battery-side microcomputer 16 of the battery pack 10 via a terminal V, thereby starting up the battery-side microcomputer 16.

The battery charger 100 is further provided with a switch circuit 170 (hereinafter referred to as "charger-side switch circuit 170"). The charger-side switch circuit 170 includes a first switch section and a second switch section. The first switch section includes a first switch SW10 and a second switch SW20. One end of the first switch SW10 is connected to the LS terminal, and the other end of the first switch SW10 is connected to the battery temperature and overcurrent detecting circuit 130. One end of the second switch SW20 is connected to the same LS terminal, and the other end of the second switch SW20 is connected to the charger-side microcomputer 140. The second switch section includes a third switch SW30 and a fourth switch SW40. One end the third switch SW30 is connected to the T terminal, and the other end of the third switch SW30 is connected to the charger-side microcomputer 140. One end the fourth switch SW40 is connected to the same T terminal, and the other end of the fourth switch SW40 is connected to the charger-side microcomputer 140.

Immediately after the battery pack 10 is mounted on the battery charger 100, the first switch SW10 constituting the first switch section is ON, and the second switch SW20 is OFF, and the third switch SW30 constituting the second switch section is ON, and the fourth switch SW40 is OFF. The first switch SW10 and the second switch SW20 of the first switch section is tuned ON/OFF in a complementary manner. Similarly, the third switch SW30 and the fourth switch SW40 of the second switch section is turned ON/OFF in a complementary manner.

Next, an operation will be described in which the battery pack is mounted on the battery charger to perform charging.

It is necessary, before starting charging, to determine whether the battery pack mounted on the battery charger is a new digital-supported type (digital-supported-type battery pack) or an existing battery pack. In addition, in order to charge the digital-supported-type battery pack 10, it is necessary to determine whether the battery charger is a new type (digital-supported-type battery charger) or an existing type.

As shown in Figs. 1 and 2, when the digital-supported-type battery pack 10 is mounted on the digital-supported-type battery charger 100, as described earlier, the first switch SW1 is ON, the second switch SW2 is OFF, the third switch SW3 is ON, and the fourth switch SW4 is OFF at the battery pack 10 side, and the first switch SW10 is ON, the second switch SW20 is OFF, the third switch SW30 is ON, and the fourth switch SW40 is OFF at the charger side.

When the digital-supported-type battery pack 10 is mounted on the digital-supported-type battery charger 100, at first, the both operates in an analog mode (S10, S100). The ON/OFF of each switch is set as described above. Hence, the battery-type identifying element 15 in the battery pack 10 is connected to the resistive element 121 constituting the battery-type determining circuit 120 in the battery charger 100, and divided voltage of the both ends of the battery-type identifying element 15 is inputted to an A/D converter of the charger-side microcomputer 140. At this time, the charger-side microcomputer 140 outputs a low-level signal to an FET element 181 constituting a short circuit 180, so that the FET element 181 is OFF. The charger-side microcomputer 140 determines at least the number of cells of the battery set 11 built in the mounted battery pack 10, based on the inputted resistance value of the battery-type identifying element 15 (S101).

The existing battery pack is not provided with a circuit corresponding to the battery-side switch circuit 19 provided in the digital-supported-type battery pack 10. Further, the existing battery charger is not provided with a circuit corresponding to the charger-side switch circuit 170 provided in the digital-supported-type battery charger 100. However, in a case where the existing battery pack is mounted on the digital-supported-type battery charger 100, and in a case where the digital-supported-type battery pack 10 is mounted on the existing battery charger, determination of the number of cells in the analog mode is performed in a way similar to those described above.

Next, the digital-supported-type battery pack 10 determines whether the battery charger on which the battery pack 10 is mounted is a digital-supported-type. In order to do this, the charger-side microcomputer 140 switches, to a high-level signal, the low-level signal that has been outputted to the FET element 181 of the short circuit 180, so that the FET element 181 becomes ON, thereby short-circuiting the T terminal (S102). In this way, although the digital-supported-type battery charger 100 has a function of short-circuiting the T terminal, the existing battery charger does not have such a function. Hence, at the battery pack 10 side, it can be determined whether the battery charger on which the battery pack is mounted is the new type or the existing type, based on whether the T terminal is short-circuited (S11). At this time, the third switch SW3 of the battery-side switch circuit 19 of the digital-supported-type battery pack 10 is OFF, and the fourth switch SW4 is ON, and thus the battery-side microcomputer 16 can recognize that the T terminal is in a short-circuited state.

If the T terminal is short-circuited (S11: YES), it is recognized at the battery pack side that the battery charger on which the battery pack is mounted is a digital-supported-type battery charger (S12). If the T terminal is not short-circuited (S11: NO), it is recognized that the battery charger on which the battery pack is mounted is an existing battery charger (S16). If the battery charger on which the battery pack is mounted is an existing battery charger, regardless of whether the battery pack is the new type or the existing type, the operation in the analog mode is continued (S17), and charging is started with the existing battery charger in the same method as the conventional method.

After it is determined at the battery pack side whether the battery charger to be used is the new type or the existing type, the battery charger 100 side determines whether the mounted battery pack is the new type or the existing type. In order to do this, short-circuit of the T terminal performed by the battery charger 100 side is cancelled (S102), it is determined whether the T terminal can be short-circuited from the battery pack 10 side. The short circuit 18 is provided in the digital-supported-type battery pack 10, and the short circuit 18 can connect the T terminal to the ground in response to a short-circuit direction signal (high-level) from the battery-pack-side microcomputer 16. If the battery charger 100 side can confirm that the T terminal is short-circuited (S104: YES), it can be known that the mounted battery pack 10 is the new digital-supported type (S108). Conversely, if the T terminal is not short-circuited (S104: NO), it is determined that the mounted battery pack 10 is the existing type (S105).

Specifically, as shown in Figs. 1 and 2, the digital-supported-type battery pack 10 is provided with the short circuit 18. As shown in Fig. 2, in the short circuit 18, the transistor 18A becomes ON in response to the short-circuit direction signal outputted from the battery-pack-side microcomputer 16. As a result, the T terminal is short-circuited (S13). The existing battery pack is not provided with this type of short circuit. Hence, because the T terminal remains connected to the battery-type identifying element 15, the T terminal is not short-circuited.

If the battery charger 100 side determines that the T terminal is not short-circuited and hence the existing battery pack is mounted (S105), the analog mode is continued (S106), and the mounted existing battery pack is charged under controls by the conventional analog method (S106). As shown in Fig. 2, if the thermistor 14 is connected to the battery temperature detecting circuit 131 at the battery charger side via the LS terminal, an analog signal indicative of temperature of the battery set 11 is inputted to the A/D converter of the charger-side microcomputer 140, and it is determined that the battery set 11 is in high temperature, then charging is stopped. Further, although not shown in Fig. 2, if the protection IC 12 outputs a fully-charge signal indicating that at least one battery cell is fully-charged, the fully-charge signal inputting section 17 outputs an abnormal signal, and the abnormal signal is sent to the battery charger side via the LS terminal. At the battery charger side, the abnormal signal from the battery pack is inputted to the charger-side microcomputer 140 via the fully-charge detecting circuit. If it is detected that the charger-side microcomputer 140 is in a fully-charge state, charging is stopped.

If the mounted battery pack 10 is the new digital-supported type (S108), the short circuit 18 at the battery pack 10 side cancels a short-circuit state of the T terminal (S14), switches the first switch SW1 to OFF, switches the second switch SW2 to ON, switches the third switch SW3 to OFF, and switches the fourth switch SW4 to ON at the battery pack 10 side, and also switches the first switch SW10 to OFF, switches the second switch SW20 to ON, switches the third switch SW30 to OFF, and switches the fourth switch SW40 to ON at the battery charger 100 side (S109). In this way, by switching each switch to a position opposite the initial state, the mode is switched from the analog mode to the digital mode (S109). In Fig. 2, signal lines in the analog mode are indicated by the solid lines, whereas signal lines in the digital mode are indicated by the dotted lines.

Upon switching to the digital mode, the charger-side microcomputer 140 built in the digital-supported-type battery charger 100 is directly connected to the battery-pack-side microcomputer 16 built in the digital-supported-type battery pack 10, so that digital communication is performed between the microcomputers (S200). The battery-side microcomputer 16 provided in the digital-supported-type battery pack 10 has a storage device, and the storage device stores battery information relating to the digital-supported-type battery pack 10. The battery information includes at least one of the charging method, the charging voltage, the charging current, the charging time, the final current, the charging capacity, the history information of charge and discharge, and the preliminary charge. These items of information are transmitted from the battery pack 10 to the digital-supported-type battery charger 100 as pulse train signals. Thus, the digital-supported-type battery charger 100 can perform charging under precise controls in accordance with characteristics of the battery pack, based on the received information relating to the battery pack. Note that, in the above-described embodiment, a connection line for transmitting information of the battery-type identifying element 15 is used as a communication line for sending the pulse train signals.

As described above, according to the present embodiment, in a case the digital-supported-type battery pack 10 is charged with the digital-supported-type battery charger 100, various charging conditions relating to battery pack to be charged can be acquired at the battery charger 100 side through digital communication. Thus, precise charging control can be performed in accordance with the characteristics of the battery pack to be charged. Further, the digital-supported-type battery pack 10 can be charged with the conventional analog-supported-type battery charger, and the analog-supported-type battery pack can also be charged with the digital-supported-type battery charger 100. Thus, compatibility is kept, which is convenient for users.

While the battery pack and the battery charger of the invention has been described in detail with reference to the above aspects thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the claims. For example, in the above-described embodiment, the existing T terminal used for determining the battery type (the number of cells) is used for performing pulse communication. However, the existing LS terminal used for transmitting the battery temperature information to the battery charger side may be used.

Next, a second embodiment of the invention will be described while referring to Figs. 3 and 4.

As shown in Fig. 3, the charging system 1' includes a battery pack 210 and a battery charger 100 for charging the battery pack 210.

The battery pack 210 includes, within a main body, a battery set 211 as a secondary battery, a protection IC 212, a switching IC 213, a temperature detecting element 214, a battery-type identifying element 215, a battery-side microcomputer 216, a fully-charge signal inputting section 217, a battery-type-identifying-element releasing means 218, and a battery-type-identifying-element short-circuiting means 219.

The battery set 211 includes one or more secondary battery cell such as lithium-ion battery. In a case where the battery set 11 includes a plurality of battery cells, a predetermined number of battery cells are connected in series, or a predetermined number of parallel-connected battery cells are connected in series.

The protection IC 212 monitors a voltage of each of the battery cells, and outputs a fully-charge signal when the protection IC 212 determines that a state different from the normal state, such as overvoltage, is generated in at least one of the battery cells.

The battery-type identifying element 215 includes a resistive element having an inherent resistance value depending on the number of battery cells constituting the battery set 211 and its connection configuration such as parallel or series connection configuration. When the battery pack 210 is mounted on the battery charger 100, one end of the battery-type identifying element 215 is electrically connected to the battery charger 100 via a terminal T4, so as to form an electrical circuit with battery charger 100.

The temperature detecting element 214 is a thermistor, and is disposed in contact with or adjacent to the battery set 211. The resistance value of the temperature detecting element 214 changes in accordance with battery temperature in the battery pack 210. When the battery pack 210 is mounted on the battery charger 100, one end of the thermistor 214 is connected to the battery charger 100 via a terminal T3, so as to form an electrical circuit with battery charger 100.

The switching IC 13 is turned ON/OFF by a signal sent from a terminal T5, and controls power supply to the battery-side microcomputer 216.

The battery-type-identifying-element releasing means 218 is a switching element connected between the other end of the battery-type identifying element 215 and the ground (GND). The battery-type-identifying-element releasing means 218 is normally in an ON state, and connects the other end of the battery-type identifying element 215 to GND. However, the battery-type-identifying-element releasing means 218 maintains an OFF state for a predetermined period d1 due to a signal input from the battery-side microcomputer 216.

The battery-type-identifying-element short-circuiting means 219 is a switching element connected between one end of the battery-type identifying element 215 and GND. The battery-type-identifying-element short-circuiting means 219 is normally in an OFF state. However, the battery-type-identifying-element short-circuiting means 219 maintains an OFF state for a predetermined period d2 due to a signal input from the battery-side microcomputer 216, so that the battery-type identifying element 215 is short-circuited.

The battery-side microcomputer 216 controls ON/OFF of the battery-type-identifying-element releasing means 18 and the battery-type-identifying-element short-circuiting means 19. Normally, the battery-side microcomputer 16 maintains the battery-type-identifying-element releasing means 18 at the ON state, and maintains the battery-type-identifying-element short-circuiting means 19 at the OFF state. Accordingly, when the battery pack 10 is mounted on the battery charger 100, the battery-type identifying element 15 forms an electrical circuit with the battery charger 100.

The battery-side microcomputer 216 internally includes a memory (not shown). The memory stores the charging method suitable for the battery pack 210, a charging voltage, a charging current, a charging time period, a final current, a charging capacity, history information of charge and discharge, conditions of preliminary charge, and the like. Hence, when mounted on the battery charger 100, the battery-side microcomputer 216 turns ON/OFF the battery-type-identifying-element releasing means 218 and the battery-type-identifying-element short-circuiting means 219, thereby outputting a pulse signal via the terminal T4, in order to transmit the charging condition to the battery charger 100. With respect to the pulse signal, when the battery-type-identifying-element releasing means 218 becomes OFF, a pulse p₁ having a pulse width d₁ and a level HIGH is generated. Conversely, when the battery-type-identifying-element short-circuiting means 219 becomes ON, a pulse p₂ having a pulse width d₂ and a level LOW is generated. In the present embodiment, as the transmission signal, a charging condition notified to the battery charger 100 is specified by the number of continuous pulses p₂. Further, a specific value of the specified charging condition is notified to the battery charger 100, based on the number of continuous pulses p₁that are generated after the charging condition is specified based on the pulses p₂. In this way, the battery-side microcomputer 216 transmits the charging condition of the battery pack 210 to the battery charger 100 via the terminal T4.

Next, the battery charger 100 will be described. In the second embodiment, the same elements as those of the first embodiment are assigned the same numeral numbers as those of the first embodiment. And the explanation to the same elements will be omitted. The battery charger 100 includes a primary-side rectifier circuit 20, a main power-source circuit 30, a transformer 40, a secondary-side rectifier circuit 50, a current controlling and setting circuit 60, a battery voltage detecting circuit 70, a voltage controlling and setting circuit 80, a feedback switching circuit 90, a constant-voltage power source circuit 110, a battery-type determining circuit 120, a battery temperature and overcurrent detecting circuit 130, a charger-side microcomputer 140, and a display means 150 such as LED.

The battery-type determining circuit 120 includes a resistive element 121 having a predetermined resistance value, and an FET 122 that is turn ON/OFF by the microcomputer 140. When the FET 122 is OFF, the resistive element 121 is in a pull-up state. Conversely, the FET 122 is ON, the lower potential end of the resistive element 121 becomes at a ground level potential, which corresponds to a state in which the terminal T4 is short-circuited. Further, when the battery pack 120 is mounted, the battery-type determining circuit 120 transmits the pulse signal inputted via the terminal T4 to an input port P1 of the charger-side microcomputer 140. Note that, when the battery pack 210 is not mounted on the battery charger 100, DC voltage Vcc is inputted to the input port P1.

Further, the battery charger 100 includes a switch circuit 260 that switches ON/OFF of power supply to the battery-side microcomputer 216 of the mounted battery pack 210. The switch circuit 260 becomes ON when the battery pack 210 is mounted. When the switch circuit 260 becomes ON, the switch circuit 260 applies the DC voltage Vcc, that is, 5V to the battery-side microcomputer 216 of the battery pack 210 via the terminal T5, thereby starting up the battery-side microcomputer 216.

Next, charging of the battery pack by the charging system 1' will be described while referring to Fig. 4. Before charging to the battery pack 210 is started, that is, at time t₀ at which the battery pack 210 is not mounted on the battery charger 100, the charger-side microcomputer 140 of the battery charger 100 controls the LED of the display means 150 to light in red color so as to indicate prior to charge. At the same time, the charger-side microcomputer 140 monitors whether the battery pack 210 is mounted. When the battery pack 210 is mounted on the battery charger 100 at time t₁, the battery-type identifying element 215 of the battery pack 210 is electrically connected to the resistive element 121 of the battery-type determining circuit 120 via the terminal T4. At this time, because in the battery pack 210 the battery-type-identifying-element releasing means 218 is normally ON and the battery-type-identifying-element short-circuiting means 219 is normally OFF, a divided voltage value obtained by dividing the DC voltage Vcc into the resistive element 121 and the battery-type identifying element 215 is inputted to the charger-side microcomputer 140. The divided voltage value indicates a value depending on the kind of the battery cells, the number of the battery cells, and the connection configuration of the mounted battery pack 210. Thanks to an input of the divided voltage value, the battery charger 100 can recognize mounting of the battery pack 210, and also can learn the kind of the battery cells, the number of the battery cells, and the connection configuration of the mounted battery pack 210.

Further, the charger-side microcomputer 140 turns the switch circuit 160 to ON due to the input of the divided voltage value, thereby starting up the battery-side microcomputer 216.

Next, after a predetermined time elapses from time t₁, between time t₂ and time t₃, the battery-side microcomputer 216 generates a first number of pulse signals p₁ with ON/OFF of the battery-type-identifying-element releasing means 218. The first number of pulse signals p₁ indicates the charging capacity of the battery pack 210. Assuming that one pulse signal p₁ corresponds to 0.5 ampere, the charging capacity of the battery pack 210 is represented by the number of the continuous pulse signals p₁ as (0. 5 ampere) x (the number of pulse signals p₁), and can be notified to the charger-side microcomputer 140 via the terminal T4 and the input port P1.

Next, at time t₃, the battery-side microcomputer 216 generates a single pulse signal p₂ due to ON/OFF of the battery-type-identifying-element short-circuiting means 219. Input of the single pulse signal p₂ to the charger-side microcomputer 140 notifies the charger-side microcomputer 140 that voltage information of the battery pack 210 is notified by the number of the pulse signals p₁ that are inputted next. After generation of the single pulse signal p_2,from time t₄ to t₅, the battery-side microcomputer 216 generates a second plural number of pulse signals p₁. Assuming that one pulse signal p₁ corresponds to a 0.1V increase of the charging voltage, a voltage increase value needed by the battery charger 100 for charging voltage that is preset based on the battery-type identifying element 215 is represented by the number of continuous pulse signals p₁ as (0. 1 V increase) x (the number of the pulse signals p₁), and can be notified to the charger-side microcomputer 140 via the terminal T4 and the input port P1.

Next, at time t₅, the battery-side microcomputer 216 continuously generates two pulse signals p₂ due to ON/OFF of the battery-type-identifying-element short-circuiting means 219. Input of the continuous two pulse signals p₂ to the charger-side microcomputer 140 preliminarily notifies the charger-side microcomputer 140 that the allowable current of the battery pack 210 is notified by the number of the pulse signals p₁ that are inputted next. After generation of the two pulse signals p_2,from time t₆ to t₇, the battery-side microcomputer 216 generates a third plural number of pulse signals p₁. Assuming that one pulse signal p₁ corresponds to 0.5A allowable current, the allowable current value of the battery pack 210 is represented by the number of continuous pulse signals p₁ as (0. 5 A) x (the number of the pulse signals p₁), and can be notified to the charger-side microcomputer 140 via the terminal T4 and the input port P1.

Next, at time t₇, the battery-side microcomputer 216 continuously generates three pulse signals p₂ due to ON/OFF of the battery-type-identifying-element short-circuiting means 219. Input of the continuous three pulse signals p₂ to the charger-side microcomputer 140 preliminarily notifies the charger-side microcomputer 140 that the final current of the battery pack 210 is notified by the number of the pulse signals p₁ that are inputted next. After generation of the three pulse signals p_2,from time t₈ to t₉, the battery-side microcomputer 216 generates a fourth number of pulse signals p₁. Assuming that one pulse signal p₁ corresponds to 0.5A final current, the final current of the battery pack 10 is represented by the number of continuous pulse signals p₁ as (0. 5 A) x (the number of the pulse signals p₁), and can be notified to the charger-side microcomputer 140.

As described above, after the charging capacity, the charging voltage, the allowable current, and the final current are notified from the battery-side microcomputer 216 to the charger-side microcomputer 140 via the terminal T4, from time t₁₀, the battery charger 100 starts charging of the battery pack 210. Also, after charging of the battery pack 210 is started, the battery pack 210 outputs information such as temperature information, a slope of voltage, a slope of temperature, for example, as necessary. Based on the information, charging control is performed as needed.

The battery pack 210 is charged with a charging method of constant current control, constant voltage control, or the like. The detailed charging conditions are notified from the battery-side microcomputer 216 to the charger-side microcomputer 140 via the terminal T4.

In the above-described embodiment, the charging capacity, the charging voltage, the allowable current, and the final current of the battery pack 10 are notified from the battery pack 210 to the battery charger 100 by using the battery-type determining circuit 120 that reads the battery-type identifying element 215. In order to charge the mounted battery pack 210, the battery charger 100 is supplied with the charging information of the battery pack from the battery pack 210, and can perform charging of the battery pack 210. Accordingly, the battery charger 100 can perform charging control suitable for the battery pack 210.

Further, the connection line (the line of the T4 terminal) connected to the battery-type identifying element 215 existing in the battery pack and the battery-type determining circuit 120 of the battery charger 100 side is used for notifying the battery charger of the charging condition. Thus, no dedicated line for notifying the charging condition is needed in the battery pack and the battery charger, which can prevent complication of the configurations of the battery pack and the battery charger.

Also, the battery pack 220 itself provides the battery charger 100 with an optimum charging condition for that charging. Thus, charging can be performed using an appropriate battery charger.

In the above-described embodiment, the connection line including the battery-type identifying element 215 is used as the communication line for sending pulse signals corresponding to charging information. The invention is not limited to this configuration. Another existing connection line such as the connection line including the temperature detecting element 214 and the connection line for reporting fully-charge, for example, may be used.

Further, as the charging information that is notified from the battery pack 210 to the battery charger 100, other than the above-described charging capacity, the charging voltage, the allowable current, and the final current, a unique identification information of battery cells, the history information of charge and discharge of the battery pack 210, the charging time period of preliminary charge of the battery pack 210, voltage threshold values and current values, temperature information, and the like may be notified.

Further, the number of continuous generation of the pulse signal p₁ and the number of continuous generation of the pulse signal p₂ are not limited to the numbers in the above-described embodiment. Also, physical quantities per one pulse may be changed appropriately.

Claims

A battery pack configured to be connectable to a power tool, comprising:
a secondary battery cell configured to be charged by a charging device; and
control means for controlling charging the secondary battery cell, characterized in that the control means comprises: signal output means for outputting a signal indicating information related to the secondary battery cell to the charging device, the signal output means being configured to output a pulsed signal indicating a charging condition for the secondary battery cell to the charging device.
The battery pack according to claim 1, characterized in that the signal indicating the information related to the secondary battery cell comprises a type of battery cell, a number of the battery cells, and connecting configuration of the battery cells included in the secondary battery cell,
wherein the charging condition for the secondary battery cell comprises at least one of a charging method, a charging voltage, a charging current, a charging time-period, and a final current for charging the secondary battery cell, a charging capacity, history information of charge and discharge, and a condition of preliminary charge.
The batter pack according to claim 1 or 2, characterized in that the signal output means outputs the signal through a terminal connected to at least one of a battery-type identifying element, a temperature detecting element, and full-charge detecting element included in the battery pack.
The battery pack according to any one of claims 1-3, wherein the control means further comprises:
battery-side connecting means for connecting to a charger-side connecting means included in the charger;
first information generating means for generating an analog signal indicating first battery information related to the secondary battery cell;
second information generating means for generating a digital signal indicating second battery information related to the secondary battery cell;
charger determination means for determining a type of the charger connected through the charger-side connecting means;
selecting and connecting means for selecting the second information generating means and connecting the second information generating means to the battery-side connecting means when the charger determination means determines that the charger is a digital type.
The battery pack according to claim 4, characterized in that the selecting and connecting means connects the first information generating means to the battery-side connecting means when the charger-side connecting means is connected to the battery-side connecting means.
The battery pack according to claim 4 or 5, characterized in that the control means further comprises:
battery pack type information transmitting means for transmitting to the charger that the battery pack connected to the charger is a digital type.
The battery pack according to claim 4 or 5, characterized in that the first information generating means comprises:
analog temperature signal generating means for detecting a temperature of the secondary battery cell and generating an analog temperature signal indicating the detected temperature of the secondary battery cell;
analog battery cell number generating means for generating analog battery cell number signal indicating a number of battery cells included in the secondary battery cell,
wherein the battery-side connecting means comprises:
a first terminal configured to output the analog temperature signal generated by the analog temperature signal generating means; and
a second terminal configured to output the analog battery cell number signal generated by analog battery cell number generating means.
The battery pack according to claim 7, characterized in that the second information generating means is connected to the second terminal.
A charging system comprising: the battery pack according to any one of claims 1-8, and a charging device configured to charge the battery pack, characterized in that the charging device comprises:
signal input means configured to connected to the signal output means; and
charging device control means for controlling charging the battery pack, wherein the charging device control means determines the charging condition on the basis of the pulsed signal received by the signal input means and charges the secondary battery cell.
The charging system according to claim 9, characterized in that the signal indicating the information related to the secondary battery cell comprises a type of battery cell, a number of the battery cells, and connecting configuration of the battery cells included in the secondary battery cell,
wherein the charging condition for the secondary battery cell comprises at least one of a charging method, a charging voltage, a charging current, a charging time-period, and a final current for charging the secondary battery cell, a charging capacity, history information of charge and discharge, and a condition of preliminary charge.
The charging system according to claim 9 or 10, characterized in that the signal output means and the signal input means treat the signal through a terminal connected to at least one of a battery-type identifying element, a temperature detecting element, and full-charge detecting element included in the battery pack.
A charging device comprising control means for charging a battery pack comprising a secondary battery cell and a terminal connectable with a power tool, the control means comprising signal input means for receiving a signal indicating information related to the secondary battery cell,
wherein the signal input means receives a pulsed signal indicating a charging condition for charging the battery pack, the charging condition being generated in the battery pack, and
the control means is configured to charge the secondary battery cell on the basis of the received charging condition.
The charging device according to claim 12, characterized in that the signal indicating the information related to the secondary battery cell comprises a type of battery cell, a number of the battery cells, and connecting configuration of the battery cells included in the secondary battery cell,
wherein the control means is configured to set at least one of a charging method, a charging voltage, a charging current, a charging time-period, and a final current for charging the secondary battery cell, a charging capacity, history information of charge and discharge, and a condition of preliminary charge as the charging condition on the basis of the type of battery cell, the number of the battery cells, and connecting configuration, and then charge the secondary battery cell.
The charging device according to claim 12 or 13, characterized in that the signal input means receives the signal through a terminal connected to at least one of a battery-type identifying element, a temperature detecting element, and full-charge detecting element included in the battery pack.
The charging device according to any one of claims 12-14, wherein the control means is configured to selectively charge one of a digital type of battery pack configured to generate a digital signal comprising the pulsed signal and an analog type of battery pack configured to respond only to an analog signal, and
wherein the control means further comprises:
charger-side connecting means connectable to a battery-side connecting means included in the battery pack;
battery pack determination means for determining whether the battery pack connected to the charger-side connecting means is the digital type or the analog type; and
the control means charges the secondary battery cell included in the battery pack connected to the charger-side connecting means in accordance with the analog signal or the digital signal transmitted through the battery-side connecting means from the connected battery pack.
The charging device according to claim 15, characterized in that the control means includes an analog to digital converting function for converting the analog signal transmitted through the battery-side connecting means to a digital signal.
The charging device according to claim 15 or 16, characterized in that the control means establishes digital communication to receive a digital signal from information generating means included in the connected digital type of battery pack when the digital type of battery pack is connected to the charger-side connecting means.
The charging device according to claim 15 or 16, characterized in that the control means establishes analog communication to receive an analog signal from information generating means included in the analog type of battery pack when the analog type of battery pack is connected to the charger-side connecting means.
A battery pack, comprising:
a secondary battery cell configured to be charged by a charger;
battery-side connecting means for connecting to a charger-side connecting means included in the charger;
first information generating means for generating an analog signal indicating first battery information related to the secondary battery cell;
second information generating means for generating a digital signal indicating second battery information related to the secondary battery cell;
charger determination means for determining a type of the charger connected through the charger-side connecting means;
selecting and connecting means for selecting the second information generating means and connecting the second information generating means to the battery-side connecting means when the charger determination means determines that the charger is a digital type.
The battery pack according to claim 19, characterized in that the selecting and connecting means connects the first information generating means to the battery-side connecting means when the charger-side connecting means is connected to the battery-side connecting means.
The battery pack according to claim 19 or 20, characterized by further comprising:
battery pack type information transmitting means for transmitting to the charger that the battery pack connected to the charger is a digital type.
The battery pack according to any one of claims 19-21, characterized in that the first information generating means comprises:
analog temperature signal generating means for detecting a temperature of the secondary battery cell and generating an analog temperature signal indicating the detected temperature of the secondary battery cell;
analog battery cell number generating means for generating analog battery cell number signal indicating a number of battery cells included in the secondary battery cell,
wherein the battery-side connecting means comprises:
a first terminal configured to output the analog temperature signal generated by the analog temperature signal generating means; and
a second terminal configured to output the analog battery cell number signal generated by analog battery cell number generating means.
The battery pack according to claim 22, characterized in that the second information generating means is connected to the second terminal.