JP3674908B2 - Battery pack - Google Patents

Description

実際には、１℃毎のサーミスタの抵抗値が規定されているため、精密に温度を計測することができる。また、このときの消費電流を低減するため、抵抗Ｒ１は、温度を測定する時だけ５Ｖにプルアップさせるようにすればよい。
【００１５】
外部の電圧の計測では、測定用電圧端子に測定したい電圧源Ｖ１を供給すると、
Ｖ１×｛Ｒ３／（Ｒ２＋Ｒ３）｝
の電圧がＡ／Ｄポートに入力される。電圧源Ｖ１の最大電圧が２０Ｖである場合には、
２０×｛Ｒ３／（Ｒ２＋Ｒ３）｝＝５Ｖ
になるように抵抗Ｒ２とＲ３を決定してやればよい。例えばＲ２＝３００ｋΩ、Ｒ３＝１００ｋΩとに決めることができる。抵抗Ｒ２、Ｒ３は、できるだけリーク電流を下げるため抵抗値を高くした方はよいが、抵抗値が高すぎるとノイズによる誤差が大きくなる。また、電池パックの＋、−の端子に測定したい電圧源Ｖ１を接続することによって電圧計測することもできる。この場合、充放電ＦＥＴは、オフにしておく。
【００１６】
電流の計測では、通常は、電池パックの充放電電流を計測するため、抵抗Ｒ５の両端の電圧をそれぞれアナログスイッチＡＳＷ１で切り換えてそれぞれを増幅し差分を計算して算出している。外部の電流を計測する場合も、同様にアナログスイッチＡＳＷ１で切り換えて抵抗Ｒ４の両端の電圧をそれぞれ増幅し差分を計算して外部の電流を算出できる。抵抗Ｒ５は、例えば３０ｍΩの抵抗と仮定すると、抵抗Ｒ４を例えば３Ωとすると、微少な電流でも計測できる。ただし、この場合は検出値を１００倍する必要がある。また、この時、抵抗Ｒ４の定格電力を越えないように電流を流す必要があるため、抵抗Ｒ４の定格電力を１Ｗで最大電流が１Ａである場合、抵抗値は１Ω以下とする必要がある。
【００１７】
なお、本発明は、上記実施の形態に限定されるものではなく、種々の変形が可能である。例えば上記実施の形態では、アナログデータ測定モードでのＡ／Ｄ変換したデジタル値を外部機器からの要求により、通信にて外部機器に送信し、あるいは表示素子２に表示したが、勿論、外部機器へ送信し、かつ表示素子２に表示してもよいし、外部機器からの要求が特になくても外部機器に送信し、表示素子に表示するように設定されていてもよい。なお、計測するアナログデータによって電池パックの充放電制御や残量管理に影響を与えないものであることはいうまでもない。
【００１８】
【発明の効果】
以上の説明から明らかなように、本発明によれば、入出力端子を通して外部機器との通信が可能なマイコンを内蔵し電池の温度、電圧、充放電電流を計測して充放電制御、残量管理を行う電池パックにおいて、マイコンのアナログ信号をデジタル信号に変換するＡ／Ｄポートに入出力端子を通して外部のアナログ計測信号を入力する信号入力手段を備え、マイコンをアナログデータ測定モードに切り換えることにより、信号入力手段から入力された外部のアナログ計測信号をデジタル値に変換して該デジタル値を外部機器からの要求にしたがって通信にて外部機器へ送信するように構成したので、電池パックに内蔵するマイコンの機能を利用して外部のデータを計測できる。
【００１９】
外部のアナログ計測信号は、サーミスタを用いた温度の計測信号、測定したい電圧源の電圧、抵抗に流れる電流の計測信号あり、信号入力手段は、電池の温度を計測するサーミスタ回路との切り換え手段や、電圧を入力して分圧する抵抗分圧回路、充放電電流の計測回路との切り換え手段を有し、マイコンは、通信にて所定のコマンドを入力したことを条件にアナログデータ測定モードの切り換えを行い、表示手段を備え、通常動作時は残量を表示し、アナログデータ測定モード時には変換したデジタル値を表示し、残量表示用スイッチを備え、該残量表示用スイッチを所定時間以上押し続けたことを条件にアナログデータ測定モードの切り換えを行うので、外部からのアナログデータを計測して外部機器に通知することができ、外部機器がＡ／Ｄコンバータを持たなくても電流、電圧、温度の計測を行うことができる。
【００２０】
したがって、例えばノートＰＣ等では、ＣＰＵの温度がかなり上昇するため、これを計測して管理することができ、ＣＰＵの温度が所定値以上になると、低消費電流モードにする等の制御が簡単にできるようになる。また、電池パックも部品の追加があまり必要なく安価に実現できる。
【図面の簡単な説明】
【図１】 本発明に係る電池パックの実施の形態を示す図である。
【符号の説明】
１…マイコン、２…表示素子、３…充放電ＦＥＴ、４…３直セル、５…入出力端子[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery pack that incorporates a microcomputer capable of communicating with an external device through an input / output terminal and performs charge / discharge control and remaining amount management by measuring battery temperature, voltage, and charge / discharge current.
[0002]
[Prior art and problems to be solved by the invention]
Battery packs called smart batteries have functions to measure charge / discharge current, battery voltage, and battery temperature. Accumulate the remaining amount based on this information and send it when requested by an external device. There is also a function to do.
[0003]
However, these functions normally measure data inside the battery pack and control charging / discharging, and have not been used for the purpose of measuring external data.
[0004]
[Means for Solving the Problems]
The present invention solves the above-described problems, and enables measurement of external data by using a function of a microcomputer built in a battery pack.
[0005]
For this purpose, the present invention provides a battery pack that incorporates a microcomputer capable of communicating with an external device through an input / output terminal and measures the temperature, voltage, and charge / discharge current of the battery to perform charge / discharge control and remaining amount management. A signal input means for inputting an external analog measurement signal to the A / D port for converting the analog signal into a digital signal through the input / output terminal, and the microcomputer is switched to the analog data measurement mode. The external analog measurement signal is converted into a digital value, and the digital value is transmitted to the external device by communication according to a request from the external device.
[0006]
The external analog measurement signal is a temperature measurement signal using a thermistor, the signal input means has a switching means with a thermistor circuit for measuring the temperature of the battery, and the external analog measurement signal is measured. The signal input means has a resistance voltage dividing circuit that inputs and divides the voltage, and the external analog measurement signal is a measurement signal of a current flowing through a resistor, and the signal The input unit has a switching unit with a charge / discharge current measuring circuit, and the microcomputer switches the analog data measurement mode on condition that a predetermined command is input by communication, and a display unit In the normal operation, the remaining amount is displayed. In the analog data measurement mode, the converted digital value is displayed, and a remaining amount display switch is provided. It is characterized in that for switching the analog data measurement mode under the condition that the switch kept pressed for a predetermined time or more a.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a battery pack according to the present invention, wherein 1 is a microcomputer, 2 is a display element, 3 is a charge / discharge FET, 4 is a 3 series cell, and 5 is an input / output terminal.
[0008]
In FIG. 1, the microcomputer 1 has an operation mode and an analog data measurement mode. The microcomputer 1 switches and controls the analog switches ASW1 and ASW2 according to the respective modes, and measures voltage, current, and temperature to measure the charge / discharge FET 3. The CPU performs control, display of the remaining amount on the display element 2, transmission of the measured value to an external device, display of the measured value on the display element 2, and the like. The analog switch ASW1 is used to select current measurement using the resistor R5 or current measurement using the resistor R4. The analog switch ASW2 is used to select temperature measurement using the thermistor TH1 or temperature measurement using the thermistor TH2. . The operational amplifier AMP1 amplifies a minute voltage generated in the resistors R4 and R5 by flowing a current and inputs the amplified voltage to the A / D port of the microcomputer 1. The charge / discharge FET 3 controls charge / discharge of the three straight cells 4. The display element 2 displays the remaining amount and the measured value, displays the remaining amount in the operation mode during normal operation, and displays data such as temperature, voltage, and current in the analog data measurement mode.
[0009]
The thermistor TH1 is connected to the outside via the input / output terminal 5 and measures the external temperature, and the thermistor TH2 measures the temperature of the cell inside the battery pack. Therefore, the thermistor TH1 has one terminal connected to the same level as the ground potential GND of the battery pack, and the other terminal pulled up to the reference voltage 5V by the resistor R1, so that the thermistor TH1 and the resistor R1 are connected at the midpoint of connection. The voltage is connected so as to be input to the A / D port of the microcomputer 1.
[0010]
The resistor R5 measures the charge / discharge current in the battery pack, and the resistor R4 is connected to the outside via the input / output terminal 5 to measure the external current. For this reason, the resistor R4 is inserted into a terminal having the same level as the ground potential GND of the battery pack so that a current to be measured flows. The resistors R2 and R3 are for measuring an external voltage. A voltage to be measured is supplied from an external measurement voltage terminal, connected in series to the input / output terminal 5 inside the battery pack, and the other end is connected to the battery pack. Is connected to the ground potential GND of the microcomputer 1 so that the voltage at the midpoint of the series connection of the resistors R2 and R3 is input to the A / D port of the microcomputer 1.
[0011]
The microcomputer 1 controls the charging / discharging of the battery pack by measuring the battery temperature, the battery voltage, the charging / discharging current, etc. and controlling the charging / discharging FET 3 based on these information in the operation mode in the normal time, Further, the remaining amount is managed and the remaining amount is displayed on the display element 2. At this time, the analog switch ASW1 is connected to the resistor R5 side for measuring the charge / discharge current, and the analog switch ASW2 is connected to the thermistor TH2 side for measuring the temperature inside the battery pack. Then, for example, switching from the operation mode to the analog data measurement mode is performed on condition that a predetermined command is input from an external device through communication. Alternatively, when a remaining amount display switch (not shown) is provided and the remaining amount is displayed on the display element 2 by pressing it, the remaining amount display switch is kept pressed for a predetermined time or more. The operation mode may be switched to the analog data measurement mode on the condition of some operation.
[0012]
In the analog data measurement mode, the analog switch ASW1 is switched to the resistor R4 side for measuring the external current, the analog switch ASW2 is switched to the thermistor TH1 side for measuring the external temperature, and the analog voltage value input from the outside through the input / output terminal 5 Is connected to the A / D converter input terminal (A / D port) of the microcomputer 1 built in the battery pack, converts the analog voltage value to a digital value, and then communicates the digital value according to a request from an external device. To the external device or displayed on the display element 2.
[0013]
In the measurement of the external temperature, if the resistor R1 is pulled up to 5V at 10kΩ, the thermistor TH1 is 10kΩ at 25 ° C, so that when the A / D input voltage value is 2.5V, it is 25 ° C. Become. Similarly, the analog voltage value can be converted into temperature data by [Table 1].
[0014]
[Table 1]

Actually, since the resistance value of the thermistor for every 1 ° C. is defined, the temperature can be measured accurately. In order to reduce the current consumption at this time, the resistor R1 may be pulled up to 5V only when measuring the temperature.
[0015]
In the measurement of the external voltage, when the voltage source V1 to be measured is supplied to the voltage terminal for measurement,
V1 × {R3 / (R2 + R3)}
Is input to the A / D port. When the maximum voltage of the voltage source V1 is 20V,
20 × {R3 / (R2 + R3)} = 5V
The resistors R2 and R3 may be determined so that For example, R2 = 300 kΩ and R3 = 100 kΩ can be determined. The resistors R2 and R3 should have a high resistance value in order to reduce the leakage current as much as possible. However, if the resistance value is too high, an error due to noise increases. The voltage can also be measured by connecting a voltage source V1 to be measured to the + and-terminals of the battery pack. In this case, the charge / discharge FET is turned off.
[0016]
In the current measurement, normally, in order to measure the charging / discharging current of the battery pack, the voltages at both ends of the resistor R5 are switched by the analog switch ASW1 and amplified to calculate the difference. In the case of measuring an external current, it is possible to calculate the external current by switching the analog switch ASW1 and amplifying the voltages at both ends of the resistor R4 and calculating the difference. Assuming that the resistor R5 is, for example, 30 mΩ, for example, if the resistor R4 is, for example, 3Ω, even a very small current can be measured. However, in this case, the detection value needs to be multiplied by 100. At this time, since it is necessary to flow a current so as not to exceed the rated power of the resistor R4, when the rated power of the resistor R4 is 1 W and the maximum current is 1 A, the resistance value needs to be 1Ω or less.
[0017]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, in the above embodiment, the digital value obtained by A / D conversion in the analog data measurement mode is transmitted to the external device by communication or displayed on the display element 2 in response to a request from the external device. And may be displayed on the display element 2 or may be set to be transmitted to the external device and displayed on the display element even if there is no particular request from the external device. Needless to say, the analog data to be measured does not affect the charge / discharge control and remaining amount management of the battery pack.
[0018]
【The invention's effect】
As is apparent from the above description, according to the present invention, a microcomputer capable of communicating with an external device through an input / output terminal is built in, and the temperature, voltage, and charge / discharge current of the battery are measured to control charge / discharge and the remaining amount. In the battery pack to be managed, the A / D port that converts the analog signal of the microcomputer into a digital signal is equipped with signal input means for inputting an external analog measurement signal through the input / output terminal, and the microcomputer is switched to the analog data measurement mode. Since the external analog measurement signal input from the signal input means is converted into a digital value and the digital value is transmitted to the external device by communication according to a request from the external device, it is built in the battery pack. External data can be measured using the functions of the microcomputer.
[0019]
The external analog measurement signal includes the temperature measurement signal using the thermistor, the voltage of the voltage source to be measured, and the measurement signal of the current flowing through the resistor, and the signal input means includes means for switching to the thermistor circuit for measuring the battery temperature, , A resistance voltage dividing circuit that divides voltage by voltage input, and a switching means with a charge / discharge current measurement circuit. And display means, display the remaining amount in normal operation, display the converted digital value in the analog data measurement mode, have a remaining amount display switch, and keep pressing the remaining amount display switch for a predetermined time or more The analog data measurement mode is switched on the condition that the analog data from the outside can be measured and notified to the external device. / D converter need not have a current, it is possible to perform voltage, the measurement of temperature.
[0020]
Therefore, for example, in a notebook PC or the like, the CPU temperature rises considerably and can be measured and managed. When the CPU temperature exceeds a predetermined value, control such as a low current consumption mode can be easily performed. become able to. In addition, the battery pack can be realized inexpensively without requiring additional parts.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a battery pack according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Microcomputer, 2 ... Display element, 3 ... Charge / discharge FET, 4 ... 3 cell, 5 ... Input / output terminal

Claims (7)

  Built-in microcomputer that can communicate with external devices through input / output terminals, and measures the battery temperature, voltage, charge / discharge current, charge / discharge control, and remaining charge management. A signal input means for inputting an external analog measurement signal through the input / output terminal to the A / D port to be converted into an analog signal, and an external analog signal input from the signal input means by switching the microcomputer to an analog data measurement mode. A battery pack configured to convert a measurement signal into a digital value and transmit the digital value to an external device through communication in accordance with a request from the external device.   2. The battery according to claim 1, wherein the external analog measurement signal is a temperature measurement signal using a thermistor, and the signal input means includes a switching means for switching to a thermistor circuit for measuring the temperature of the battery. pack.   2. The battery pack according to claim 1, wherein the external analog measurement signal is a voltage of a voltage source to be measured, and the signal input means has a resistance voltage dividing circuit for inputting and dividing the voltage.   2. The battery pack according to claim 1, wherein the external analog measurement signal is a measurement signal of a current flowing through a resistor, and the signal input means includes a switching means for switching to a charge / discharge current measurement circuit.   The battery pack according to claim 1, wherein the microcomputer switches the analog data measurement mode on condition that a predetermined command is input through communication.   2. The battery pack according to claim 1, further comprising a display means for displaying a remaining amount during normal operation and displaying the converted digital value in an analog data measurement mode.   7. The battery pack according to claim 6, further comprising a remaining amount display switch, wherein the analog data measurement mode is switched on condition that the remaining amount display switch is continuously pressed for a predetermined time or more.

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