JP6233094B2 - Battery pack remaining amount detection device - Google Patents

Description

  The present invention relates to a battery pack remaining amount detection device that detects the remaining amount of a battery pack having a built-in constant voltage charge / discharge circuit.

  In general, the remaining amount value indicating the remaining amount of the battery is indicated based on the output voltage of the battery. However, since the output voltage of the battery fluctuates with a change in temperature, the output current value is detected by detecting the output current and temperature. In addition, there is a battery that accurately determines the remaining state of the battery by comparing the threshold value set for the detected temperature and the output voltage (see, for example, Patent Document 1).

  In addition, the virtual battery remaining amount is calculated based on the battery profile and the operating state of the terminal device without measuring the actual terminal voltage of the secondary battery, and the remaining virtual battery remaining amount is calculated using the calculated virtual battery remaining amount. There is one that performs quantity display (see, for example, Patent Document 2).

  Here, a lithium ion battery with a high energy density is often used as a power source for devices such as robots and portable terminals, in which small size and light weight are important. When using a lithium ion battery, a control circuit for ensuring safety is indispensable, and there is a need to use it as a device power source in a battery pack equipped with the control circuit.

JP 2008-185445 A JP 2010-206706 A

  However, most lithium-ion battery packs for consumer use have a built-in constant voltage charge / discharge circuit, and the voltage of the battery cell itself cannot be known from the outside. Also, disassembling the battery pack for that purpose leads to a decrease in safety and reliability. In such a battery pack, since the input / output voltage is constant, it is impossible to know the remaining amount of the battery pack based on the output voltage as in Patent Document 1.

  Further, in Patent Document 2, the virtual battery remaining amount is calculated based on the battery profile and the operating state of the terminal device without measuring the actual terminal voltage of the secondary battery. If it is not a secondary battery, the actual battery level is measured from the battery voltage, etc., and the actual battery level is obtained. To know the battery level, the terminal voltage of the secondary battery is required. . Further, it is conceivable to obtain the remaining amount by integrating the input / output currents, but in that case, the absolute value of the remaining amount is not known.

  An object of the present invention is to provide a battery pack remaining amount detection device capable of detecting the remaining amount of a battery pack having a constant input / output voltage.

  The battery pack remaining amount detection device according to the present invention includes a discharge current detection unit that detects a discharge current of the battery pack when the battery pack having a constant input / output voltage is discharged, and the discharge current detection unit that discharges the battery pack. A first remaining amount calculating means for calculating the remaining amount of the battery pack based on the detected discharge current; and a characteristic curve showing a relationship between a charging current during charging of the battery pack and the remaining amount of the battery pack. A storage unit preliminarily stored as a charging current profile, a charging current detection unit that detects a charging current of the battery pack when the battery pack is charged, and a charging current detected by the charging current detection unit when the battery pack is charged Based on the increase / decrease direction and the current value of the charging current, the remaining amount of the battery pack at the start of charging of the battery pack is calculated, and changes with the charging of the battery pack. Second remaining amount calculating means for calculating a remaining amount of the battery pack based on a characteristic curve of a charging current and a charging current profile, wherein the first remaining amount calculating means calculates the charge calculated by the second remaining amount calculating means. The remaining amount of the battery pack is calculated by subtracting the amount of discharge calculated based on the discharge current by the first remaining amount calculating means from the remaining amount of the battery pack.

  According to the present invention, since the remaining amount of the battery pack at the time of discharging is calculated by the first remaining amount calculating means, the remaining amount of the battery pack after use can be obtained. In addition, when the charging of the battery pack after use is started, the second remaining amount calculating means calculates the remaining amount of the battery pack at the start of charging based on a predetermined charging current profile. Can be sought. By comparing these, a calculation error in the first remaining amount calculating means can be detected. Therefore, the remaining amount of the battery pack can be obtained even when the battery pack incorporating the constant voltage charge / discharge circuit is used.

  The second remaining amount calculating means obtains the remaining amount of the battery pack after charging based on the charging current profile, and the first remaining amount calculating means calculates from the remaining amount of the battery pack after charging calculated by the second remaining amount calculating means. Since the remaining amount of the battery pack is calculated by subtracting the discharge amount calculated based on the discharge current by the first remaining amount calculating means, the calculation error in the first remaining amount calculating means can be eliminated. Therefore, even when a battery pack incorporating a constant voltage charge / discharge circuit is used, the remaining amount of the battery pack can be obtained more accurately.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram of the battery pack residual amount detection apparatus which concerns on 1st Embodiment of this invention. The graph which shows the charge characteristic of a lithium ion battery. The graph which shows the charge characteristic of the battery pack of 1st Embodiment. Explanatory drawing of a charging current profile. The block diagram of the battery pack residual amount detection apparatus which concerns on 2nd Embodiment of this invention. Explanatory drawing of the charging current profile which used the charging / discharging cycle as a parameter. The battery pack remaining charge detection apparatus which concerns on 3rd Embodiment of this invention. Explanatory drawing of preparation of the charging current profile by a charging current profile preparation means. The block diagram of the battery pack residual amount detection apparatus which concerns on 3rd Embodiment of this invention. The graph which shows an example of the time change of the discharge current of the battery pack mounted in a remote control robot.

  Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram of a battery pack remaining amount detection device according to a first embodiment of the present invention. The battery pack remaining amount detection device according to the first embodiment of the present invention includes a discharge current detection unit 12 that detects the discharge current Iout of the battery pack 11 and an amplifier 13 that amplifies the discharge current Iout detected by the discharge current detection unit 12. And a charging current detecting means 14 for detecting the charging current Iin of the battery pack 11, a calculation unit 15, and a storage unit 16. The calculating part 15 and the memory | storage part 16 are formed with a microcomputer, for example.

  The battery pack 11 includes a constant voltage charging / discharging circuit including a charger 18 that charges the battery cell 17 and a discharger 19 that discharges the battery cell 17. The battery pack 11 receives the input voltage Vin and the output voltage Vout of the battery cell 17. Keep constant. The discharge current Iout of the battery pack 11 detected by the discharge current detection unit 12 is amplified by the amplifier 13 and input to the first remaining amount calculation unit 20 of the calculation unit 15. The amplifier 13 is provided because a resistance element is used as the discharge current detecting means 12, and thus the resistance value of the resistance element is reduced in order to reduce the power loss of the battery pack 11. That is, since the resistance value of the resistance element is small, the value obtained by converting the detected current into a voltage is small.

  The first remaining amount calculating means 20 calculates the remaining amount of the battery pack 11 based on the discharge current Iout of the battery pack 11. Specifically, the discharge amount is calculated by integrating the discharge current Iout, and the remaining amount of the battery pack 11 is subtracted from the first remaining amount stored in the first remaining amount storage unit 21 of the storage unit 16. Is calculated. The first remaining amount storage unit 21 stores, as an initial value, the remaining amount of the battery pack 11 after charging calculated by the second remaining amount calculating means 22 described later as the first remaining amount. The remaining amount of the battery pack 11 is calculated by subtracting the discharge amount from the amount, and updated and stored in the first remaining amount storage unit 21. Thereby, the remaining amount of the battery pack 11 that changes from moment to moment is stored in the first remaining amount storage unit 21.

  On the other hand, the charging current Iin of the battery pack 11 detected by the charging current detection unit 14 is input to the second remaining amount calculation unit 22 of the calculation unit 15. Since the power of the battery pack 11 is not consumed during charging, the resistance element of the charging current detection means 14 can be increased, so that no amplifier is provided in FIG. Increasing the resistance element of the charging current detection means 14 can increase the measurement accuracy. Further, an amplifier may be provided. In that case, an amplifier having a smaller amplification factor than that of the amplifier 13 that amplifies the discharge current Iout detected by the discharge current detection means 12 may be used.

  The second remaining amount calculating means 22 is based on the charging current Iin of the battery pack 11 and the charging current profile stored in advance in the charging current profile storage unit 23 of the storage unit 16, and the battery pack 11 at the start of charging of the battery pack 11. The remaining amount is calculated and stored in the second remaining amount storage unit 24. Further, the remaining amount of the battery pack 11 is calculated based on the charging current Iin that changes with the charging of the battery pack 11 and the characteristic curve of the charging current profile, and is updated and stored in the second remaining amount storage unit 24 as the second remaining amount. To do. Thereby, the remaining amount of the battery pack 11 at the start of charging and the remaining amount of the battery pack 11 being charged are stored in the second remaining amount storage unit 24, and finally the remaining amount of the battery pack 11 after charging is stored. Remembered.

  The remaining amount initialization unit 25 uses the remaining amount at the end of charging of the battery pack 11 calculated by the second remaining amount calculation unit 22 as the remaining amount of the battery pack 11 when the charging of the battery pack 11 is completed. It is. Specifically, the remaining amount initialization unit 25 stores the second remaining amount stored in the second remaining amount storage unit 24 in the first remaining amount storage unit 21 when the charging of the battery pack 11 is completed. Let That is, as the first remaining amount, the remaining amount of the battery pack 11 after charging calculated by the second remaining amount calculating unit 22 is stored as an initial value. The remaining amount initialization unit 25 is not necessarily provided. When the battery pack 11 is completely charged, the second remaining amount of the second remaining amount storage unit 24 is manually stored in the first remaining amount storage unit 21. You may make it memorize | store as 1 remaining amount.

  Next, the charging current profile will be described. The charging current profile uses the same type of battery pack in advance to determine the change in the input current Iin when charging from 0 to 100% remaining, and the charging current Iin when charging the battery pack 11 and the remaining battery pack 11 Is a file indicated by a characteristic curve showing the relationship between

  Here, constant current-constant voltage charging is usually used for charging the lithium ion battery. FIG. 2 is a graph showing the charging characteristics of the lithium ion battery. As shown in FIG. 2, in the case of charging from a state where the remaining amount of the lithium ion battery is zero, since the constant current charging is initially performed, the battery end input current I of the lithium ion battery is constant and the battery end input voltage V Gradually increases. Then, when the battery terminal input voltage V of the lithium ion battery reaches a predetermined value V0, the charging current is gradually reduced by shifting to constant voltage charging.

  On the other hand, in the case of charging the battery pack 11 according to the first embodiment of the present invention, since the battery pack 11 has a built-in constant voltage charging / discharging circuit, the control of constant current-constant voltage charging is constant voltage charging / discharging. The circuit charger 18 does. FIG. 3 is a graph showing the charging characteristics of the battery pack 11 of the first embodiment. As shown in FIG. 3, no voltage change appears in the input voltage Vin of the battery pack 11, but the input power does not change inside and outside the battery pack 11, so that if the loss of the charger 18 is ignored, the change in the input current Iin appear. That is, the input current Iin of the battery pack 11 increases during constant current charging of the voltage cell 17 of the battery pack 11, and the input current Iin decreases after shifting to constant voltage charging.

  Therefore, using the same type of battery pack, a change in the input current Iin when the remaining amount is charged from 0 to 100% is stored in the charging current profile storage unit 23 as a charging current profile. When the battery pack 11 is actually charged and discharged, the remaining amount of the battery pack 11 is detected by comparing the absolute value of the current and the direction of increase / decrease with the charge current profile.

  FIG. 4 is an explanatory diagram of a charging current profile. The vertical axis represents the charging current Iin during charging, the horizontal axis represents the remaining amount of the battery pack 11, and the charging current profile represents a characteristic curve during charging of the battery pack 11. As shown in FIG. 4, the charging current Iin when the remaining amount of the battery pack 11 is 0% is I0, and the charging current Iin when the remaining amount of the battery pack 11 is 100% is I100. When the battery cell 17 of the battery pack 11 is in constant current charging, the charging current Iin of the battery pack 11 has a monotonically increasing characteristic, and when the battery cell 17 of the battery pack 11 is switched to constant voltage charging, the charging current Iin is in a monotonically decreasing characteristic. It becomes. The inflection point H is a switching point from the constant current charging to the constant voltage charging.

  Assume that the charging current Iin at the start of charging the battery pack 11 is I1. In this case, since there is an inflection point H in the characteristic curve of the charging current profile, the remaining amount corresponding to the charging current I1 is the Ka point (a1%) and the Kb point (b1%) across the inflection point H. There are two places, and the remaining amount of the battery pack at the start of charging cannot be determined. Therefore, the second remaining amount calculating means 22 acquires charging currents Iin at a plurality of time points at predetermined time intervals from the start of charging, and determines the increase / decrease direction of the charging current Iin. When the charging current Iin is in the increasing direction, it is before the inflection point H (in constant current charging), and when the charging current Iin is in the decreasing direction, it is before the inflection point H (in constant voltage charging). is there. For example, if the charging current I1 is acquired at the charging start time t1 and the charging current I2 is acquired at the next time t2, the remaining amount of the battery pack at the start of charging is a1% (Ka point). If the charging current I1 is acquired at t1 and the charging current I3 is acquired at the next time t2, the remaining amount of the battery pack at the start of charging is b1% (Kb point).

  As described above, the second remaining amount calculating means 22 calculates the remaining amount of the battery pack 11 at the start of charging of the battery pack 11 based on the increasing / decreasing direction of the charging current Iin and the current value of the charging current Iin. Further, the remaining amount of the battery pack 11 is calculated as the second remaining amount based on the charging current Iin that changes as the battery pack 11 is charged and the characteristic curve of the charging current profile. For example, the remaining amount of the battery pack 11 is obtained from the charging current Ix at the time tx acquired at predetermined intervals, and updated and stored in the second remaining amount storage unit 24 of the storage unit 16. Normally, charging is performed up to full charge (100%), but in some cases, charging may be terminated at X% before full charge (100%). In that case, X% is stored in the second remaining amount storage unit 24 as the remaining amount.

  According to the first embodiment of the present invention, the remaining amount of the battery pack at the time of discharge is integrated by the discharge current Iout by the first remaining amount calculating means 21 to calculate the discharge amount and stored in the first remaining amount storage unit 21. Since the remaining amount of the battery pack 11 is calculated by subtracting the discharge amount from the first remaining amount, the remaining amount of the used battery pack can be obtained.

  In addition, when the charging of the battery pack after use is started, the second remaining amount calculating unit 22 calculates the remaining amount of the battery pack 11 at the start of charging based on a predetermined charging current profile. However, the remaining amount of the battery pack after use can be obtained, and the calculation error in the first remaining amount calculation unit 21 can be calculated by comparing with the remaining amount of the battery pack after use obtained by the first remaining amount calculation unit 21. Can be detected.

  Further, the second remaining amount calculating means 22 obtains the remaining amount of the battery pack after charging in the charging current profile, and uses the obtained remaining amount of the charged battery pack as the initial value of the battery pack. Therefore, the calculation error in the first remaining amount calculating means 20 can be eliminated.

  In particular, when the battery pack equipped with the battery pack remaining amount detection device according to the first embodiment of the present invention is mounted on a remote operation robot that performs work or investigation of a place where a human cannot enter, the battery pack When the remaining amount of the battery pack becomes small, it is necessary to pull back to the rechargeable portion. Therefore, the remaining amount of the battery pack 11 is monitored by transmitting the first remaining amount calculated by the first remaining amount calculating means 20 to the remote control unit. ing. Accordingly, when the battery pack starts to be charged, the second remaining amount calculating means 22 calculates the remaining amount of the battery pack 11 at the start of charging, and compares it with the remaining amount of the battery pack obtained by the first remaining amount calculating means 21. It is important to detect the calculation error of the remaining amount calculating means 21 for work and investigation of the remote control robot. In the case of a remote operation robot equipped with a battery pack having a large calculation error, it can be pulled back to a chargeable portion early, so that the remote operation robot can be prevented from being unable to run due to a shortage of remaining amount.

  Next, a second embodiment of the present invention will be described. FIG. 5 is a configuration diagram of a battery pack remaining amount detection device according to the second embodiment of the present invention. The second embodiment is different from the first embodiment shown in FIG. 1 in that the storage unit 16 is provided with a charge / discharge cycle number storage unit 26 and the charge / discharge cycle number storage unit 26 has a charge / discharge cycle of the battery pack 11. A plurality of charging current profiles corresponding to the number of charge / discharge cycles of the battery pack 11 are stored in the charging current profile storage unit 23 of the storage unit 16 in advance, A charge current profile is selected according to the number of charge / discharge cycles of the battery pack 11, and the remaining amount of the battery pack 11 is calculated. The same elements as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  Generally, the battery cell 17 of the battery pack 11 is deteriorated by repeating the charge / discharge cycle. As the battery pack 11 deteriorates, the charging current profile has a characteristic that the constant current charging time is shortened. FIG. 6 is an explanatory diagram of a charge current profile using the charge / discharge cycle as a parameter. A curve S1 in FIG. 6 is a characteristic curve of the charging current profile of the new battery pack 11, and a curve S2 in FIG. 6 is a characteristic curve of the charging current profile of the deteriorated battery pack 11 with many charge / discharge cycles.

  As shown in FIG. 6, the constant voltage charging time becomes longer as the deterioration of the battery pack 11 progresses, so the inflection point, which is a switching point from constant current charging to constant voltage charging, moves from H1 to H2. In the characteristic curve of the charging current profile of the new battery pack 11, the current change during constant voltage charging is large as shown in the area E1, and in the characteristic curve of the charging current profile of the battery pack 11 having a large number of charge / discharge cycles, it is shown in the area E2. Thus, the current change at the time of constant voltage charge becomes small. Thereby, in the battery pack 11 having a large number of charge / discharge cycles, the charge amount tends to decrease as a total. Therefore, the remaining charge cannot be accurately expressed in the initial charge current profile (the charge current profile of a new battery pack) such that the remaining charge at the point where the transition from constant current charging to constant voltage charging is actually small.

  Therefore, in the second embodiment of the present invention, for example, a charge / discharge cycle is repeated in advance with the same type of battery pack, and a plurality of deteriorated charge current profiles are acquired and stored in the charge current profile storage unit 23. deep. The charge / discharge cycle number storage unit 26 stores the number of times the battery pack 11 is charged as the number of charge / discharge cycles. The number of charge / discharge cycles is a value obtained by converting the charge / discharge amount into the number of times of charging. This is because a cycle of “charge amount (power storage amount) 0% → charge amount (power storage amount) 100% → charge amount (power storage amount) 0%” and “charge amount (power storage amount) 60 → charge amount ( This is because the degree of deterioration of the battery pack 11 changes even in the same one cycle when the cycle of “storage amount) 80% → charge amount (storage amount) 60” is repeated. Therefore, for example, a case where the battery pack 11 having a charge amount (storage amount) of 100% is used (discharged) to a charge amount (storage amount) of 0% and is charged to 100% of the charge amount (storage amount) is charged / discharge cycle number “ 1 ”. Therefore, when the battery pack 11 having a charge amount (storage amount) of 80% is used up to a charge amount (storage amount) of 60% and charged to a charge amount (storage amount) of 80%, the number of charge / discharge cycles is 0.2 cycles. Is converted and stored. In addition, when the battery pack 11 having a charge amount (storage amount) of 80% is used up to a charge amount (storage amount) of 60% and charged to a charge amount (storage amount) of 100%, the number of charge / discharge cycles is 0.3 cycles. Is converted and stored.

  The number of times the battery pack is charged is determined when the remaining amount at the end of charging of the battery pack 11 calculated by the second remaining amount calculating unit 22 by the remaining amount initializing unit 25 is stored in the first remaining amount storage unit 21. It is added to the charge / discharge cycle number of the discharge cycle number storage unit 26 and updated and stored.

  Which charge current profile is selected by the second remaining amount calculating means 22 is determined based on the charge / discharge cycle stored in the charge / discharge cycle number storage unit 26. When the number of charge / discharge cycles is small, a charge current profile with a small number of charge / discharge cycles is selected, and when the number of charge / discharge cycles is large, a charge current profile with a large number of charge / discharge cycles is selected. As a result, when the battery pack 11 is still new and the current change during constant voltage charging is large, a charging current profile with a small number of charge / discharge cycles is selected, and the battery deteriorates and the current change during constant voltage charging becomes dull. In this case, a charging current profile having a large number of charge / discharge cycles is selected. In this manner, the remaining amount correction for the number of charge / discharge cycles can be performed during charging. In the above description, the charging current profile is selected according to the number of charge / discharge cycles. However, the charging current profile may be selected based on a current change during constant voltage charging.

  According to the second embodiment of the present invention, in addition to the effects of the first embodiment, the remaining charge of the battery pack 11 can be calculated by selecting an appropriate charging current profile according to the number of charge / discharge cycles of the battery pack 11. Therefore, the remaining amount of the battery pack 11 can be calculated more accurately according to the degree of deterioration of the battery pack 11.

  Next, a third embodiment of the present invention will be described. FIG. 7 is a configuration diagram of a battery pack remaining amount detection device according to the third embodiment of the present invention. This third embodiment is different from the second embodiment shown in FIG. 5 in that the charging current profile is created based on the locus of the charging current Iin detected by the charging current detecting means 14 when the battery pack 11 is charged. A profile creation means 27 is additionally provided. The same elements as those in FIG.

  The charging current profile creation unit 27 creates a charging current profile based on the locus of the charging current Iin detected by the charging current detection unit 14 when the battery pack 11 is charged, and stores the charging current profile in the charging current profile storage unit 23. The charging current profile creating means 27 may be activated every time it is charged, but may be activated every predetermined number of times because the charging current profile increases when it is activated each time it is charged.

  The charging current profile created by the charging current profile creating means 27 is applied to another battery pack 11 of the same type. That is, instead of acquiring a plurality of deteriorated charging current profiles in advance by repeating charge / discharge cycles with the same type of battery pack in advance in the second embodiment, the charging current profile creating means 27 in actual operation of the battery pack 11 Create a charge current profile.

  FIG. 8 is an explanatory diagram for creating a charging current profile by the charging current profile creating means 27. As shown in FIGS. 8A, 8B, and 8C, the charging current profile creation unit 27 obtains charging currents Iin at a plurality of time points at predetermined time intervals from the start of charging, and displays the locus of the charging current Iin. I will draw. In this case, the horizontal axis indicates the remaining amount, but the remaining amount also changes with time during charging, so that the charging current profile of the battery pack 11 can be created based on the locus of the charging current Iin.

  According to the third embodiment of the present invention, it is possible to create a charging current profile in actual operation of the battery pack 11 without acquiring a plurality of deteriorated charging current profiles by repeating charge / discharge cycles in advance with the same type of battery pack. By creating the charging current profile by means 27, for example, it is possible to create a charging current profile according to the battery pack 11 mounted on the remote control robot. In the above description, the case where the charging current profile creating means 27 is additionally provided with respect to the second embodiment shown in FIG. 5 has been described. However, the charging current profile is different from that of the first embodiment shown in FIG. The creation means 27 may be additionally provided.

  Next, a fourth embodiment of the present invention will be described. FIG. 9 is a configuration diagram of a battery pack remaining amount detection device according to the third embodiment of the present invention. The fourth embodiment is different from the third embodiment shown in FIG. 7 in that the base load current storage unit 28 stores in advance base load current when the battery pack 11 supplies current only to the base load; When the battery pack 11 supplies a current only to the base load, a remaining amount correcting means 29 for adjusting the amplifier 13 so that the discharge current Iout matches the base load current stored in the base load current storage unit 28 in advance. Is added. The same elements as those in FIG.

  When the battery pack 11 is discharged, it is important to keep the loss low in order to maintain the battery cells 17 of the battery pack for a long time. For this reason, the detection resistance of the discharge current detection means 12 is desired to be a small value, but if the resistance value is reduced, a value with sufficient accuracy for the analog input resolution of the arithmetic unit 15 cannot be obtained. Therefore, the amplifier 13 is provided as described above. When the detection signal of the discharge current detecting means 12 is amplified, an error due to offset or drift generally occurs.

  The battery pack 11 mounted on the remote operation robot includes an electric motor that drives a traveling wheel of the remote operation robot, an electric motor that drives a work device, a control device (for example, a microcomputer) that controls driving of the remote operation robot, and an electronic device. Electric power is supplied to (for example, a camera and a detector). An electric motor is a load with large fluctuations in power consumption, and a control device and an electronic device are loads with little fluctuation in power consumption. When the remote control robot is running or the work equipment is being driven, the electric current is activated, so that the discharge current from the battery pack 11 increases. On the other hand, when the driving of the remote control robot and the driving of the work equipment are stopped, the power consumption of the electric motor becomes zero. On the other hand, control devices and electronic devices must maintain their operating state for control and monitoring even when the motor is stopped. It is.

  FIG. 10 is a graph showing an example of the change over time of the discharge current Iout of the battery pack mounted on the remote control robot. In the battery pack 11 mounted on the remote operation robot, the discharge current Iout changes according to the power consumption of the remote operation robot. In the period T1 from the time point t0 to the time point t1, the time period T2 from the time point t2 to the time point t3, and the time period T3 from the time point t4 to the time point t5, the control device and the electronic device consume power constantly. Corresponds to load current. The period from the time point t1 to the time point t2, the period from the time point t3 to the time point t4, and the period from the time point t5 are periods in which the motor is driven in addition to the base load current.

  Therefore, the battery pack 11 pays attention to the power consumption of the base load such as the control device or the electronic device, and the base load current corresponding to the power consumption of the base load is measured in advance and stored in the base load current storage unit 28. deep. Then, the remaining amount correction unit 29 calculates the discharge current Iout when the control device is not driving a load (for example, an electric motor) with large power consumption fluctuations and the base load current stored in the base load current storage unit 28. In comparison, the amplification factor of the amplifier 13 is adjusted in advance so that the discharge current Iout when the battery pack 11 supplies current only to the base load matches the base load current. Thereby, the error of the detection signal of the discharge current detection unit 12 can be corrected, and the remaining amount (first remaining amount) of the battery pack calculated by the first remaining amount calculation unit 20 can be made more accurate.

  In the above description, the case where the base load current storage unit 28 and the remaining amount correction means 29 are additionally provided with respect to the third embodiment shown in FIG. 7 has been described. However, the first embodiment shown in FIG. In addition to the second embodiment shown in FIG. 5, the base load current storage unit 28 and the remaining amount correction unit 29 may be additionally provided.

  Further, in each of the above embodiments, the battery pack 11 is provided with the calculation unit 15 and the storage unit 16 for detecting the remaining amount. However, in the case of the battery pack mounted on the remote operation robot, the remote operation robot You may form in the monitoring control apparatus (microcomputer) which supervises and controls. Further, instead of the microcomputer mounted on the remote operation robot, the remote operation robot may be provided in a remote operation unit that remotely operates the remote operation robot.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 11 ... Battery pack, 12 ... Discharge current detection means, 13 ... Amplifier, 14 ... Charge current detection means, 15 ... Calculation part, 16 ... Memory | storage part, 17 ... Battery cell, 18 ... Charger, 19 ... Discharger, 20 ... 1st remaining amount calculating means, 21... 1st remaining amount storage unit, 22... 2nd remaining amount calculating unit, 23... Charging current profile storing unit, 24. 26... Charging / discharging cycle number storage unit, 27... Charging current profile creation unit, 28... Base load current storage unit, 29.

Claims (5)

A discharge current detecting means for detecting a discharge current of the battery pack when the battery pack has a constant input / output voltage;
First remaining amount calculating means for calculating the remaining amount of the battery pack based on the discharge current detected by the discharge current detecting means when the battery pack is discharged;
A storage unit storing a characteristic curve indicating a relationship between a charging current at the time of charging the battery pack and a remaining amount of the battery pack in advance as a charging current profile;
Charging current detecting means for detecting a charging current of the battery pack when charging the battery pack;
The battery pack calculates the remaining amount of the battery pack at the start of charging the battery pack based on the charging current increase / decrease direction detected by the charging current detection means and the current value of the charging current when the battery pack is charged. Second remaining amount calculating means for calculating the remaining amount of the battery pack based on a charging current that changes as the pack is charged and a characteristic curve of the charging current profile, wherein the first remaining amount calculating means includes the second remaining amount calculating means. A battery characterized in that the remaining amount of the battery pack is calculated by subtracting the amount of discharge calculated based on the discharge current by the first remaining amount calculating means from the remaining amount of the battery pack after charging calculated by the remaining amount calculating means. Pack remaining amount detection device.   When charging of the battery pack is completed at the time of charging the battery pack, the remaining amount of the battery pack at the end of charging of the battery pack calculated by the second remaining amount calculating means is set as the remaining amount of the battery pack. The battery pack remaining amount detection device according to claim 1, further comprising a quantity initialization unit.   The storage unit stores the number of charge / discharge cycles of the battery pack and stores a plurality of the charge current profiles according to the number of charge / discharge cycles of the battery pack in advance. 3. The battery pack remaining amount detection device according to claim 1, wherein the remaining amount of the battery pack is calculated by selecting the charging current profile according to the number of charge / discharge cycles of the battery pack.   4. A charging current profile creating means for creating a charging current profile based on a locus of the charging current detected by the charging current detecting means when the battery pack is charged. The battery pack remaining amount detection device according to item 1.   When the battery pack supplies current only to the base load, the battery pack further includes a remaining amount correction unit that adjusts the amplification factor of the discharge current detection unit so that the discharge current matches the base load current stored in advance. The battery pack residual quantity detection apparatus of any one of Claims 1 thru | or 4 characterized by these.

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