Charging and self-discharging detection device and method for energy storage element

Abstract

The invention relates to an energy storage element charging and self-discharging detection device and a method thereof. The energy storage element charging and self-discharging detection device comprises a charging output circuit, a measuring circuit and a processing unit, the charging output circuit comprises a voltage output unit and an operational amplifier; the measuring circuit comprises a voltage sensing element, a temperature sensing element and a current sensing element; the voltage sensing element and the temperature sensing element sense the battery end voltage and temperature of the energy storage element to obtain battery end voltage information and temperature information; the processing unit outputs a first voltage through the voltage output unit by using the battery end voltage information, the temperature information and the current temperature information; the operational amplifier compares a second voltage associated with the first voltage and a third voltage associated with the battery terminal voltage to output a first self-discharge detection current. The current sensing element senses a first self-discharge detection current.

Description

Technical Field

[0001] This disclosure relates to a charging and self-discharge detection device and method, and more particularly to a charging and self-discharge detection device and method for an energy storage element. Background Technology

[0002] The remaining capacity of a battery is called its state of charge (SOC), which can be determined by referring to the open circuit voltage (OCV) versus state of charge chart. Please refer to [reference needed]. Figure 1 This is an example of an open-circuit voltage versus charge state comparison diagram. As the remaining capacity of a battery decreases, its open-circuit voltage also decreases. Currently, most methods for measuring a battery's self-discharge current use the difference in charge state after the battery has been left to rest to estimate the self-discharge current.

[0003] Please refer to Figure 2 The attached diagram is an example of the open-circuit voltage of a battery at rest; as shown. Figure 2 As shown, the open-circuit voltage of the first battery, Cell1, decreased from approximately 3.443 volts to 3.433 volts from day 1 to day 60, while through... Figure 1 It can be seen that the state of charge corresponding to open-circuit voltages of 3.443 volts and 3.433 volts are approximately 12% and 10%, respectively. Therefore, it can be concluded that the state of charge of the first battery Cell1 decreased by approximately 2% after 60 days. If the total capacity of the first battery Cell1 is 60 ampere-hours, then the self-discharge current of the first battery Cell1 can be calculated to be approximately 0.83 mA (2% * 60 ampere-hours / (60 days * 24 hours) = 1.2 ampere-hours / 1440 hours ≈ 0.83 mA).

[0004] Similarly, Figure 2 The open-circuit voltage of the second battery, Cell2, shown decreased from approximately 3.45 volts to 3.362 volts from day 1 to day 60, while the voltage through... Figure 1 It can be seen that the state of charge corresponding to open-circuit voltages of 3.45 volts and 3.362 volts are approximately 13.5% and 3%, respectively. Therefore, it can be concluded that the state of charge of the second battery Cell2 decreased by approximately 10.5% after 60 days. If the total capacity of the second battery Cell2 is 60 ampere-hours, then the self-discharge current of the second battery Cell2 can be calculated to be 4.375 mA (10.5% * 60 ampere-hours / (60 days * 24 hours) = 6.3 ampere-hours / 1440 hours = 4.375 mA).

[0005] However, the above method requires the battery to be left for a long time and must first obtain the open circuit voltage versus state of charge map to calculate, and the actual battery production line currently produced battery needs to be left for at least 30 days to generate enough voltage difference to estimate the size of the battery self-discharge current calculation, very time-consuming. Moreover, the open circuit voltage of the battery will change with temperature, so the above method will become inaccurate without considering the influence of temperature, or need to be tested in a fixed temperature environment, thus increasing the cost of test equipment. SUMMARY

[0006] To solve the above problems, the purpose of the present disclosure is to provide a kind of energy storage element charging and self-discharge detection device.

[0007] To solve the above problems, the purpose of the present disclosure is to provide a kind of energy storage element charging and self-discharge detection device.

[0008] To achieve the above purposes of the present disclosure, the energy storage element charging and self-discharge detection device of the present disclosure is applied to an energy storage element, the energy storage element has a battery end voltage, the energy storage element charging and self-discharge detection device includes: a charging output circuit; a measurement circuit electrically connected to the charging output circuit; and a processing unit electrically connected to the charging output circuit and the measurement circuit, wherein the charging output circuit includes: a voltage output unit electrically connected to the processing unit and used to output a first voltage; and an operational amplifier electrically connected to the voltage output unit, including a positive input terminal, a negative input terminal and an output terminal, wherein the positive input terminal is used to receive a second voltage associated with the first voltage, the negative input terminal is used to receive a third voltage associated with the battery end voltage, and the output terminal is electrically connected to the energy storage element, the operational amplifier compares the second voltage and the third voltage to output a first self-discharge detection current through the output terminal.

[0009] To achieve the above-mentioned further object of the present disclosure, the energy storage element charging and self-discharge detection method of the present disclosure comprises: a voltage sensing element senses a battery terminal voltage of an energy storage element at a sensing time point to obtain a battery terminal voltage information; a temperature sensing element senses a temperature of the energy storage element at the sensing time point to obtain a temperature information; within a predetermined time, the voltage sensing element senses the battery terminal voltage at multiple sensing time points to obtain multiple battery terminal voltage information and transmits the battery terminal voltage information to a processing unit; within the predetermined time, the temperature sensing element senses the temperature of the energy storage element at the sensing time points to obtain multiple temperature information and transmits the temperature information to the processing unit; the processing unit calculates a first voltage using the battery terminal voltage information, the temperature information and the current temperature information; the processing unit sets and outputs the first voltage using a voltage output unit; and the processing unit measures a first self-discharge detection current using a measurement circuit.

[0010] The effect of the present disclosure is that the self-discharge state of the energy storage element can be known more accurately and faster.

[0011] For a further understanding of the technology, methods, and effects of the present disclosure, and to achieve the intended purposes of the present disclosure, refer to the following detailed description and accompanying drawings; in addition, the purpose, characteristics and features of the present disclosure can be understood more deeply and specifically; however, the accompanying drawings are provided only for reference and description, and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 FIG. 1 is an example of an open circuit voltage versus state of charge graph;

[0013] Figure 2 FIG. 2 is an example of an open circuit voltage of a battery at rest;

[0014] Figure 3 FIG. 3 is a circuit block diagram of an embodiment of the energy storage element charging and self-discharge detection device of the present disclosure;

[0015] Figure 4 FIG. 4 is a graph of an embodiment of the continuous temperature voltage recording value of the present disclosure;

[0016] Figure 5 FIG. 5 is a graph of an embodiment of the linear regression temperature and voltage of the present disclosure;

[0017] Figure 6 FIG. 6 is a circuit block diagram of another embodiment of the energy storage element charging and self-discharge detection device of the present disclosure;

[0018] Figure 7 FIG. 7 is a flowchart of the energy storage element charging and self-discharge detection method of the present disclosure;

[0019] Figure 8 Flow chart of an embodiment of the actual operation of the charging and self-discharge detection method of the energy storage element of the present disclosure.

[0020]

Symbol Description

[0021] 10: Energy storage element charging and self-discharge detection device

[0022] 20: Energy storage element

[0023] 102: Charging output circuit

[0024] 104: Measurement circuit

[0025] 106: Processing unit

[0026] 108: Voltage output unit

[0027] 110: Operational amplifier

[0028] 112: Positive input terminal

[0029] 114: Negative input terminal

[0030] 116: Output terminal

[0031] 118: Voltage sensing element

[0032] 120: Battery terminal voltage information

[0033] 122: Temperature sensing element

[0034] 124: Temperature information

[0035] 126: Temperature sensor

[0036] 128: Analog-to-digital conversion element

[0037] 130: Current sensing element

[0038] 132: Analog-to-digital converter

[0039] 134: First voltage dividing circuit

[0040] 136: Second voltage dividing circuit

[0041] Cell1: First battery

[0042] Cell2: Second battery

[0043] i0: Self-discharge current

[0044] i1: First self-discharge detection current

[0045] i2: Second self-discharge detection current

[0046] R1: first resistor

[0047] R2: second resistor

[0048] R3: third resistor

[0049] R4: fourth resistor

[0050] R5: fifth resistor

[0051] R6: sixth resistor

[0052] S502: step

[0053] S504: step

[0054] S506: step

[0055] S508: step

[0056] S510: step

[0057] S512: step

[0058] S514: step

[0059] S516: step

[0060] S602: step

[0061] S604: step

[0062] S606: step

[0063] S608: step

[0064] S610: step

[0065] S612: step

[0066] S614: step

[0067] S616: step

[0068] S618: step

[0069] SW: mode switching switch

[0070] Vo: battery terminal voltage

[0071] Vo1: third voltage

[0072] Vref1: first voltage

[0073] Vref2: reference voltage

[0074] Vx: second voltage DETAILED DESCRIPTION

[0075] In the present disclosure, a number of specific details are provided to provide a thorough understanding of the embodiments of the present disclosure; however, it will be apparent to those skilled in the art that the present disclosure can be practiced without one or more of the specific details. In other instances, well-known details are not shown or described in order to avoid obscuring the features of the present disclosure. The technical field of the present disclosure is the field of battery detection and battery management system (BMS). The technical content and detailed description of the present disclosure are as follows, and are illustrated by the accompanying drawings.

[0076] Please refer to Figure 3 which is a circuit block diagram of an embodiment of the energy storage element charging and self-discharge detection device 10 of the present disclosure; the energy storage element charging and self-discharge detection device 10 of the present disclosure is applied to an energy storage element 20 (for example, a battery) having a battery terminal voltage Vo and a self-discharge current i0, and the energy storage element charging and self-discharge detection device 10 includes a charging output circuit 102, a measurement circuit 104, a processing unit 106, and a mode switching switch SW, the charging output circuit 102 includes a voltage output unit 108, an operational amplifier 110, and a third resistor R3, the operational amplifier 110 includes a positive input terminal 112, a negative input terminal 114, and an output terminal 116, the measurement circuit 104 includes a voltage sensing element 118, a temperature sensing element 122, and a current sensing element 130, the temperature sensing element 122 includes a temperature sensor 126 and an analog-to-digital conversion element 128, the current sensing element 130 includes a first resistor R1 and an analog-to-digital converter 132, the above-mentioned elements are electrically connected to each other, and the mode switching switch SW is electrically connected to the processing unit 106 and arranged between the energy storage element 20 and the current sensing element 130 (i.e., the first resistor R1).

[0077] The processing unit 106 is a microcontroller, the voltage output unit 108 is a digital-to-analog conversion element (for example, a digital-to-analog converter (DAC)), the voltage sensing element 118 is an analog-to-digital converter (ADC), and the analog-to-digital conversion element 128 is an analog-to-digital converter. The charging output circuit 102 can also be referred to as an adjustable high-precision charging output circuit. The energy storage element charging and self-discharge detection device 10 of the present disclosure includes a measurement mode and a charging detection mode, which are described in detail as follows.

[0078] In the measurement mode, the processing unit 106 turns off the mode switch SW so that the energy storage element 20 is not connected to the current sensing element 130 (i.e., the first resistor Rl), the voltage sensing element 118 senses the battery terminal voltage Vo at a sensing time point to obtain a battery terminal voltage information 120, and at the same time, the temperature sensing element 122 senses a temperature of the energy storage element 20 at the sensing time point to obtain a temperature information 124; that is, at the same sensing time point, the battery terminal voltage Vo (the battery terminal voltage information 120) of the energy storage element 20 being sensed corresponds to the temperature (the temperature information 124) of the energy storage element 20 being sensed.

[0079] In the measurement mode, within a predetermined time (e.g., a day), the voltage sensing element 118 senses the battery terminal voltage Vo at a plurality of the sensing time points to obtain a plurality of the battery terminal voltage information 120 and transmits these battery terminal voltage information 120 to the processing unit 106, and the temperature sensing element 122 senses the temperature of the energy storage element 20 at the sensing time points to obtain a plurality of the temperature information 124 and transmits these temperature information 124 to the processing unit 106, and the processing unit 106 receives and records these battery terminal voltage information 120 and these temperature information 124 to obtain a plurality of temperature voltage recorded values, the processing unit 106 linearly regresses the plurality of temperature voltage recorded values by least square method to obtain an equation one, wherein the equation one stored by the processing unit 106 is Vn=a*Tn+b, where Vn is the battery terminal voltage Vo (also referred to as the open circuit voltage of the energy storage element 20), Tn is the temperature, and a and b are obtained by least square method regression.

[0080] Please refer to Figure 4 which is a drawing of an embodiment of the continuous temperature voltage recorded values graph of the present disclosure. The embodiment of the temperature corresponding voltage table of the present disclosure is shown in Table One below, wherein the temperature and voltage in Table One can also be average temperature and average voltage:

[0081] Table One:

[0082] Temperature Tn (degrees Celsius) Voltage Vn (volts) … … 24.9 3.460368 25.1 3.460341 25.3 3.460293 25.5 3.460240 25.7 3.460183 25.9 3.460119 … …

[0083] Please refer to Figure 5 which is a drawing of an embodiment of the linear regression temperature and voltage of the present disclosure. In an embodiment of the present disclosure, a is -0.0002469 and b is 3.466495.

[0084] After the processing unit 106 obtains a and b of the equation one, the energy storage element charging and self-discharge detection device 10 of the present disclosure can enter the charging detection mode. Please refer again to Figure 3In the charging detection mode: the processing unit 106 turns on the mode switching switch SW to connect the energy storage element 20 to the current sensing element 130 (i.e., the first resistor R1), the positive input terminal 112 is used to receive a second voltage Vx associated with a first voltage Vref1, and the negative input terminal 114 is used to receive a third voltage Vo1 associated with the battery terminal voltage Vo. The processing unit 106 uses Equation 1 and the current temperature information 124 (provided by the temperature sensing element 122) to calculate Vn (i.e., the battery terminal voltage Vo) in Equation 1.

[0085] Then, due to Figure 3 The operational amplifier 110 has electrical characteristics such that the battery terminal voltage Vo, the third voltage Vo1, and the second voltage Vx are all equal, and the second voltage Vx is equal to the first voltage Vref1. Therefore, the processing unit 106 calculates that the first voltage Vref1 is equal to the battery terminal voltage Vo. Then, the processing unit 106 uses the voltage output unit 108 to set and output the first voltage Vref1, which is equal to the battery terminal voltage Vo, to the positive input terminal 112. The operational amplifier 110 compares the second voltage Vx (i.e., the first voltage Vref1) and the third voltage Vo1 to output a first self-discharge detection current i1 through the output terminal 116. Finally, the current sensing element 130 senses the first self-discharge detection current i1 and notifies the processing unit 106 of the state of the first self-discharge detection current i1. The first self-discharge detection current i1 is equivalent to the self-discharge current i0, for the reasons described below.

[0086] When the energy storage element 20 self-discharges, its state of charge (SOC) gradually decreases, and therefore its battery terminal voltage Vo also gradually decreases. The energy storage element charging and self-discharge detection device 10 disclosed herein can charge the energy storage element 20 to maintain the battery terminal voltage Vo (i.e., maintain the SOC at the appropriate temperature) that the energy storage element 20 should have at that temperature. In this equilibrium state, the energy supplied to the energy storage element 20 (i.e., the first self-discharge detection current i1) can be regarded as the energy of the self-discharge of the energy storage element 20 (i.e., the self-discharge current i0), so sensing the first self-discharge detection current i1 can be regarded as sensing the self-discharge current i0.

[0087] Please refer to Figure 6 This is a circuit block diagram of another embodiment of the energy storage element charging and self-discharge detection device 10 disclosed herein; Figure 6 The components shown are Figure 3The elements shown the same, for the sake of brevity, so here will not repeat its description. The charging output circuit 102 also includes a first voltage dividing circuit 134 (including a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6) and a second voltage dividing circuit 136 (including a second resistor R2 and a third resistor R3), the first voltage dividing circuit 134 electrically connected to the voltage output unit 108 and the operational amplifier 110, the second voltage dividing circuit 136 one end electrically connected to the energy storage element 20 to receive the battery terminal voltage Vo, the second voltage dividing circuit 136 the other end electrically connected to the negative input terminal 114. The first voltage dividing circuit 134 receives the first voltage Vref1 and a reference voltage Vref2, and converts the first voltage Vref1 and the reference voltage Vref2 into the second voltage Vx. The second voltage dividing circuit 136 converts the battery terminal voltage Vo into the third voltage Vo1 (that is, converts the first self-discharge detection current i1 into a second self-discharge detection current i2).

[0088] Furthermore, as described above, the second voltage dividing circuit 136 includes a second resistor R2 and a third resistor R3, the second resistor R2 electrically connected to the energy storage element 20 and the negative input terminal 114, the third resistor R3 electrically connected to the second resistor R2 and the negative input terminal 114. The first voltage dividing circuit 134 includes a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6, the fourth resistor R4 electrically connected to the positive input terminal 112, the fifth resistor R5 electrically connected to the positive input terminal 112, the fourth resistor R4 and the voltage output unit 108 and receives the first voltage Vref1, the sixth resistor R6 electrically connected to the positive input terminal 112, the fourth resistor R4 and the fifth resistor R5 and receives the reference voltage Vref2. The processing unit 106 stores the following equation two and equation three to calculate the first voltage Vref1.

[0089] The equation two is:

[0090] The equation three is:

[0091] wherein Vx is the second voltage, R4 is the fourth resistance, R6 is the sixth resistance, R5 is the fifth resistance, Vrefl is the first voltage, Vref2 is the reference voltage, Vo is the battery terminal voltage, R2 is the second resistance, R3 is the third resistance, the operation symbol / / in the equation two and the equation three represents resistance in parallel. Since the battery terminal voltage Vo can be calculated by the equation one and the current temperature information 124, and the second resistance R2 and the third resistance R3 are also known (the processing unit 106 can memorize), the second voltage Vx can be calculated by the equation three, and the fourth resistance R4, the sixth resistance R6, the fifth resistance R5 and the reference voltage Vref2 are also known (the processing unit 106 can memorize), so the first voltage Vrefl can be calculated by the equation two.

[0092] The charging output circuit 102 can adjust the precision of the charging output (i.e. the minimum unit of value that can be adjusted for each output) by adjusting the resistance values of the first voltage dividing circuit 134 and the second voltage dividing circuit 136; for example, a 2.048 volt 12-bit DAC has a voltage output adjustment precision of 2.048 volts / 2 12 = 0.5 millivolt, so the adjustment precision of one step of output without the assistance of these voltage dividing resistances is 0.5 millivolt, which is calculated as the following example one.

[0093] Example one: (0.5 mV*1) - (0.5 mV*0) = 0.5 mV

[0094] However, the voltage dividing design of Figure 6 can improve the precision of the battery terminal voltage Vo, in the following example two of table two, the precision of the output can be improved to 0.38 millivolt with the assistance of these voltage dividing resistances, and even in the following example three of table two, it can be improved to 0.079 millivolt, which is described in detail as follows, wherein the units of resistance are all kilo-ohms, and the units of voltage are all volts:

[0095] Table two:

[0096]

[0097] The equation two and the equation three can be calculated as follows for example two and example three, respectively:

[0098] Example two:

[0099] Example three:

[0100] Please refer to Figure 7which is a flowchart of a charging and self-discharge detection method of an energy storage element of the present disclosure. The charging and self-discharge detection method of the energy storage element comprises the following steps:

[0101] Step S502: Start. Then, the charging and self-discharge detection method of the energy storage element proceeds to step S504.

[0102] Step S504: At a sensing time point, a voltage sensing element senses a battery terminal voltage of an energy storage element to obtain a battery terminal voltage information, and a temperature sensing element senses a temperature of the energy storage element to obtain a temperature information. Then, the charging and self-discharge detection method of the energy storage element proceeds to step S506.

[0103] Step S506: Within a predetermined time, the voltage sensing element senses the battery terminal voltage at multiple sensing time points to obtain multiple battery terminal voltage information and transmits the battery terminal voltage information to a processing unit, and the temperature sensing element senses the temperature of the energy storage element at the sensing time points to obtain multiple temperature information and transmits the temperature information to the processing unit. That is, within the predetermined time, the voltage sensing element senses the battery terminal voltage at multiple first sensing time points to obtain the battery terminal voltage information and transmits the battery terminal voltage information to the processing unit; within the predetermined time, the temperature sensing element senses the temperature of the energy storage element at multiple second sensing time points to obtain the temperature information and transmits the temperature information to the processing unit; wherein the first sensing time points and the second sensing time points are the same. Then, the charging and self-discharge detection method of the energy storage element proceeds to step S508.

[0104] Step S508: The processing unit calculates a first voltage by using the battery terminal voltage information, the temperature information and the current temperature information. Then, the charging and self-discharge detection method of the energy storage element proceeds to step S510.

[0105] Step S510: The processing unit sets and outputs the first voltage by using a voltage output unit. Then, the charging and self-discharge detection method of the energy storage element proceeds to step S512; wherein the following steps S512, S514 and S516 represent that the processing unit measures a first self-discharge detection current by using a measurement circuit.

[0106] Step S512: A positive input end of an operational amplifier receives a second voltage associated with the first voltage, and a negative input end of the operational amplifier receives a third voltage associated with the battery terminal voltage. Then, the charging and self-discharge detection method of the energy storage element proceeds to step S514.

[0107] Step S514: The operational amplifier compares the second voltage and the third voltage to output the first self-discharge detection current. Then, the energy storage element charging and self-discharge detection method enters step S516.

[0108] Step S516: A current sensing element senses the first self-discharge detection current.

[0109] In one embodiment, the second voltage is equal to the first voltage, and the third voltage is equal to the battery terminal voltage. In another embodiment, a first voltage dividing circuit receives the first voltage and a reference voltage and converts the first voltage and the reference voltage into the second voltage, and a second voltage dividing circuit receives the battery terminal voltage and converts the battery terminal voltage into the third voltage.

[0110] Please refer to Figure 8 , which is a flowchart of an embodiment of the actual operation of the energy storage element charging and self-discharge detection method of the present disclosure. The energy storage element charging and self-discharge detection method comprises the following steps:

[0111] Step S602: Start. Then, the energy storage element charging and self-discharge detection method enters step S604.

[0112] Step S604: Detect and record a plurality of battery terminal voltages and corresponding temperatures of an energy storage element as the table one described above; wherein, as shown in Figure 6 the mode switching switch SW is turned off. Then, the energy storage element charging and self-discharge detection method enters step S606.

[0113] Step S606: Is greater than a measurement cutoff time? The measurement cutoff time is, for example, one day, that is, for example, the first day. If it is not greater than the measurement cutoff time, the energy storage element charging and self-discharge detection method returns to step S604; if it is greater than the measurement cutoff time, the energy storage element charging and self-discharge detection method enters step S608. In other words, in steps S604 and S606, the first day of the energy storage element charging and self-discharge detection device 10 of the present disclosure is the measurement mode described above, and the processing unit 106 records the battery terminal voltages Vo and the corresponding temperatures. Since the temperature is continuously changing as shown in Figure 4 , the processing unit 106 performs calculations to obtain its linear equation (i.e., the equation one described above) as shown in Figure 5 .

[0114] Step S608: Detect the current temperature and calculate the battery terminal voltage using the equation one described above; wherein, as shown in Figure 6The mode switch SW is turned on. Then, the energy storage element charging and self-discharge detection method enters step S610.

[0115] Step S610: a first voltage is calculated using the aforementioned equation two and equation three. Then, the energy storage element charging and self-discharge detection method enters step S612.

[0116] Step S612: the processing unit outputs the first voltage to a positive input terminal of an operational amplifier using a voltage output unit. Then, the energy storage element charging and self-discharge detection method enters step S614.

[0117] Step S614: a first self-discharge detection current output by the operational amplifier is detected and recorded. Then, the energy storage element charging and self-discharge detection method enters step S616.

[0118] Step S616: whether it is greater than a detection cutoff time; the detection cutoff time is, for example, one day, i.e., for example, the second day. If it is not greater than the detection cutoff time, the energy storage element charging and self-discharge detection method returns to step S608; if it is greater than the detection cutoff time, the energy storage element charging and self-discharge detection method enters step S618. In other words, in steps S608 to S616, the second day that the energy storage element charging and self-discharge detection device 10 is started is the aforementioned charging detection mode, the processing unit 106 calculates the battery terminal voltage Vo (also referred to as the target voltage) using the aforementioned equation one, and outputs the first voltage Vref1 using the voltage output unit 108, the battery terminal voltage Vo is updated to the battery terminal voltage Vo calculated by the aforementioned equation one as the temperature changes, and then the processing unit 106 obtains a plurality of the first self-discharge detection currents i1 output by the operational amplifier 110 using the aforementioned current sensing element 130.

[0119] Step S618: the first self-discharge detection currents are calculated to obtain an individual self-discharge current average. Finally, the first self-discharge detection currents i1 measured within one day (i.e., within the second day) are averaged to obtain the individual self-discharge current average.

[0120] Furthermore, the following embodiments illustrate how to determine whether the energy storage element 20 is normal or abnormal:

[0121] First, the processing unit 106 obtains a plurality of the first self-discharge detection currents i1 from the current sensing element 130 and calculates the first self-discharge detection currents i1 to obtain an individual self-discharge current average of the energy storage element 20. Next, the energy storage element charging and self-discharge detection device 10 senses a plurality of the energy storage elements 20 to obtain a group self-discharge current average of the energy storage elements 20. Then, the processing unit 106 calculates a self-discharge current standard deviation of the energy storage elements 20 according to the group self-discharge current average. Finally, if the individual self-discharge current average of the energy storage element 20 is greater than 6 times the self-discharge current standard deviation, the processing unit 106 determines that the energy storage element 20 is abnormal; if the individual self-discharge current average of the energy storage element 20 is less than or equal to 6 times the self-discharge current standard deviation, the processing unit 106 determines that the energy storage element 20 is normal.

[0122] In more detail, the above can include the following Equation Four, Equation Five, Judgment Formula One and Judgment Formula Two:

[0123] Equation Four:

[0124] Equation Five:

[0125] Judgment Formula One:

[0126] Judgment Formula Two:

[0127] wherein, is the group self-discharge current average, k is the number of the energy storage elements 20 sensed (i.e., k energy storage elements 20 produced by a production line are sensed), i is from 1 to k, and I sd is the individual self-discharge current average, S Isd is the self-discharge current standard deviation (or can be referred to as the sample standard deviation). If the Judgment Formula One is true, the processing unit 106 determines that the energy storage element 20 is abnormal; if the Judgment Formula Two is true, the processing unit 106 determines that the energy storage element 20 is normal.

[0128] In summary, in order to accelerate the self-discharge measurement of the energy storage element 20 and reduce the cost of production line setup for manufacturing the energy storage element 20, the energy storage element charging and self-discharge detection device 10, the energy storage element charging and self-discharge detection method and the related content provided by the present disclosure can be used to detect the self-discharge current of the energy storage element 20 in the production line to further detect the energy storage element 20 with self-discharge failure in the production line, and the entire detection process does not need to use the open circuit voltage-charge state comparison chart, so the self-discharge state of the energy storage element 20 can be known without using the charging and discharging machine used to obtain the open circuit voltage-charge state comparison chart.

[0129] When the energy storage element 20 self-discharges, the SOC of the energy storage element 20 will gradually decrease, and the present disclosure can charge the energy storage element 20 to a specific SOC to measure the first self-discharge detection current i1 equivalent to the self-discharge current i0 of the energy storage element 20. The present disclosure can also use a voltage dividing element to further improve the measurement accuracy and shorten the measurement time. The present disclosure also has a temperature compensation mechanism that can adapt to changes in the ambient temperature in the production line to accurately estimate the battery terminal voltage Vo of the energy storage element 20. The charging output circuit 102 can also adjust the voltage operating range and accuracy of the battery terminal voltage Vo according to different energy storage elements 20. The present disclosure can be used for product testing in conjunction with the mass production of energy storage elements 20, and can adapt to temperature changes in the mass production environment without the need to build a constant temperature device.

[0130] The effect of the present disclosure is to obtain more accurate self-discharge state of the energy storage element 20 more quickly.

[0131] Although the present disclosure has been described with reference to the embodiments thereof, it is to be understood that the present disclosure is not limited to the details thereof; various substitutions and modifications have been proposed in the foregoing description, and it will occur to those skilled in the art that other substitutions and modifications can be made without departing from the scope of the present disclosure; therefore, all such substitutions and modifications are intended to be included within the scope of the present disclosure.

Claims

1. A device for detecting the charging and self-discharge of an energy storage element, characterized in that, This is applied to an energy storage element having a battery terminal voltage. The energy storage element charging and self-discharge detection device includes: One charging output circuit; A measuring circuit is electrically connected to the charging output circuit; and A processing unit is electrically connected to the charging output circuit and the measurement circuit. The charging output circuit includes: A voltage output unit, electrically connected to the processing unit and used to output a first voltage; and An operational amplifier, electrically connected to the voltage output unit, includes a positive input terminal, a negative input terminal, and an output terminal. The positive input terminal is used to receive a second voltage associated with the first voltage, the negative input terminal is used to receive a third voltage associated with the battery terminal voltage, and the output terminal is electrically connected to the energy storage element. The operational amplifier compares the second voltage and the third voltage to output a first self-discharge detection current through the output terminal.

2. The energy storage element charging and self-discharge detection device according to claim 1, characterized in that, The measurement circuit includes at least: A voltage sensing element, electrically connected to the processing unit, is used to sense the battery terminal voltage at a sensing time point to obtain battery terminal voltage information; and A temperature sensing element is electrically connected to the processing unit and is used to sense a temperature of the energy storage element at the sensing time point to obtain temperature information.

3. The energy storage element charging and self-discharge detection device according to claim 2, characterized in that, The measurement circuit also includes a current sensing element electrically connected to the processing unit and the operational amplifier, and is used to sense the first self-discharge detection current.

4. The energy storage element charging and self-discharge detection device according to claim 3, characterized in that, Within a predetermined time period, the voltage sensing element senses the battery terminal voltage at multiple sensing time points to obtain multiple battery terminal voltage information and transmits the battery terminal voltage information to the processing unit. At the same time, the temperature sensing element senses the temperature of the energy storage element to obtain multiple temperature information and transmits the temperature information to the processing unit. The processing unit receives and records the battery terminal voltage information and the temperature information. The processing unit calculates the first voltage using the battery terminal voltage information, the temperature information, and the current temperature information. Then, the processing unit uses the voltage output unit to set and output the first voltage.

5. The energy storage element charging and self-discharge detection device according to claim 4, characterized in that, The second voltage is equal to the first voltage, and the third voltage is equal to the battery terminal voltage.

6. The energy storage element charging and self-discharge detection device according to claim 4, characterized in that, The temperature sensing element includes a temperature sensor and an analog-to-digital converter, the analog-to-digital converter being electrically connected to the processing unit and the temperature sensor; the voltage output unit is a digital-to-analog converter, and the voltage sensing element is an analog-to-digital converter.

7. The energy storage element charging and self-discharge detection device according to claim 4, characterized in that, The current sensing element includes a first resistor and an analog-to-digital converter. The first resistor is electrically connected to the output terminal, and the analog-to-digital converter is electrically connected to the output terminal, the first resistor, and the processing unit.

8. The energy storage element charging and self-discharge detection device according to claim 4, characterized in that, The charging output circuit also includes a first voltage divider circuit, which is electrically connected to the voltage output unit and the operational amplifier. The first voltage divider circuit receives the first voltage and a reference voltage, and converts the first voltage and the reference voltage into the second voltage.

9. The energy storage element charging and self-discharge detection device according to claim 8, characterized in that, The charging output circuit also includes a second voltage divider circuit. One end of the second voltage divider circuit is electrically connected to the energy storage element to receive the battery terminal voltage, and the other end of the second voltage divider circuit is electrically connected to the negative input terminal. The second voltage divider circuit converts the battery terminal voltage into the third voltage.

10. A method for detecting charging and self-discharge of an energy storage element, characterized in that, Include: A voltage sensing element senses the battery terminal voltage of an energy storage element at a sensing time point to obtain battery terminal voltage information; A temperature sensing element senses a temperature of the energy storage element at the sensing time point to obtain temperature information; Within a predetermined time period, the voltage sensing element senses the battery terminal voltage at multiple sensing time points to obtain multiple battery terminal voltage information and transmits the battery terminal voltage information to a processing unit. During the predetermined time period, the temperature sensing element senses the temperature of the energy storage element at the sensing time points to obtain multiple temperature information and transmits the temperature information to the processing unit. The processing unit uses the battery terminal voltage information, the temperature information, and the current temperature information to calculate a first voltage; The processing unit utilizes a voltage output unit to set and output the first voltage; and The processing unit uses a measurement circuit to measure a first self-discharge detection current.

11. The method for detecting charging and self-discharge of an energy storage element according to claim 10, characterized in that, Also includes: An operational amplifier receives a second voltage associated with the first voltage at one of its positive input terminals. One negative input terminal of the operational amplifier receives a third voltage associated with the battery terminal voltage; and The operational amplifier compares the second voltage and the third voltage to output the first self-discharge detection current.

12. The method for detecting charging and self-discharge of an energy storage element according to claim 11, characterized in that, Also includes: A current sensing element senses the first self-discharge detection current.

13. The method for detecting charging and self-discharge of an energy storage element according to claim 12, characterized in that, The second voltage is equal to the first voltage, and the third voltage is equal to the battery terminal voltage.

14. The method for detecting charging and self-discharge of an energy storage element according to claim 12, characterized in that, Also includes: A first voltage divider circuit receives the first voltage and a reference voltage, and converts the first voltage and the reference voltage into the second voltage.

15. The method for detecting charging and self-discharge of an energy storage element according to claim 14, characterized in that, Also includes: A second voltage divider circuit receives the battery terminal voltage and converts the battery terminal voltage into the third voltage.

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