Battery deterioration level determination device and method

Abstract

To provide a battery deterioration degree determination device which determines a deterioration degree of a nickel hydrogen battery before use start, and a method thereof.SOLUTION: A battery deterioration degree determination device 10 is packaged with a nickel hydrogen battery 1 shipped from a factory. The determination device 10 comprises: a timer 17 which measures the elapsed time from a time point of being packaged with the nickel hydrogen battery or a time point of being shipped; a thermometer 11 which measures the ambient temperature of the nickel hydrogen battery for each prescribed time; a microcomputer 12 which calculates the deterioration degree of the nickel hydrogen battery from the elapsed time and the history of the ambient temperatures; and a memory 13 which stores the deterioration degree together with the elapsed time. The deterioration degree is used for life prediction in a device 20 incorporating the nickel hydrogen battery 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a battery degradation level determination device and a battery degradation level determination method. [Background technology]

[0002] Generally, the deterioration of nickel-metal hydride batteries is affected by the ambient temperature in which they are installed, so after they start to be used, parameters such as the ambient temperature are monitored to predict when the batteries need to be replaced. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-92047 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-9406 Summary of the Invention [Problem to be solved by the invention]

[0004] Nickel-metal hydride batteries are used in a variety of fields, and the ambient temperature of the battery varies widely depending on the storage conditions and transportation method used from the time of shipment to the time of first use. However, to determine the battery's lifespan, a fixed value has been used as an index indicating the battery's deterioration up to the time of first use. Therefore, to ensure the continuous operation of the device incorporating the battery, the battery life has been calculated with a margin for error, i.e., a shorter value than the predicted lifespan. This has led to batteries being replaced even when they are actually usable, resulting in battery waste.

[0005] In general, nickel-metal hydride batteries are often used in groups, and it is known that fewer batteries will deteriorate when the ambient temperature of the storage or use location is low, while more batteries will deteriorate when the ambient temperature is high.

[0006] An object of the present invention is to provide an apparatus and method for determining the degree of deterioration of a battery before it is put into use. [Means for solving the problem]

[0007] The present invention is a battery deterioration level determination device that is packaged with at least one nickel-metal hydride battery to be shipped, and is characterized by comprising: a timer that measures the elapsed time from the time the battery is packaged with the nickel-metal hydride battery or from the time the battery is shipped; a temperature measurement means that measures the ambient temperature of the nickel-metal hydride battery at predetermined intervals; a microcomputer that calculates the degree of deterioration of the nickel-metal hydride battery from the elapsed time and the history of the ambient temperature; and a memory that stores the degree of deterioration together with the elapsed time, and the degree of deterioration is used to predict the lifespan of the nickel-metal hydride battery depending on the usage environment. [Effects of the Invention]

[0008] According to the present invention, the degree of deterioration of a nickel-metal hydride battery at the start of use can be accurately determined based on the period from packaging or shipping of the included nickel-metal hydride battery to the start of use and the ambient temperature history during that period. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram showing the configuration of a nickel-metal hydride battery deterioration level determination device according to an embodiment; [Figure 2] 4 is a flowchart for calculating the deterioration level of a nickel-metal hydride battery. [Figure 3] FIG. 1 is a diagram illustrating how deterioration of a nickel-metal hydride battery progresses over time. DETAILED DESCRIPTION OF THE INVENTION

[0010] A deterioration level determining device for a nickel-metal hydride battery according to one embodiment will be described with reference to the drawings.

[0011] The nickel-metal hydride battery 1 (hereinafter referred to as "battery") to be subjected to the deterioration assessment is a type of secondary battery. The battery 1 has a positive electrode plate containing a nickel oxide compound such as nickel oxyhydroxide, and a negative electrode plate containing a hydrogen-containing hydrogen storage alloy or a hydrogen compound. The positive and negative electrode plates are wound spirally facing each other with a porous separator interposed between them to form an electrode group, which is then sealed in a cylindrical outer can together with an electrolyte consisting of an alkaline solution such as a concentrated potassium hydroxide (KOH) aqueous solution. One end of the outer can serves as the positive electrode terminal 2, and the other end as the negative electrode terminal 3. The battery 1 is packed in a package 4 together with a nickel-metal hydride battery deterioration assessment device 10 in preparation for shipment.

[0012] As shown in FIG. 1, a nickel-metal hydride battery deterioration level determining device (hereinafter referred to as "determination device") 10 has a thermometer 11, a microcomputer 12, a memory 13, a communication interface 14, and a display unit 15 inside a main body 16.

[0013] Thermometer 11 serves as a temperature measurement means and outputs the measured temperature to microcomputer 12. Thermometer 11 may be an appropriate temperature measurement device such as a thermistor, thermograph, or thermocouple. Microcomputer 12 treats the temperature measured by thermometer 11 as the ambient temperature of battery 1, which is packaged with main body 16.

[0014] The microcomputer 12 includes a timer 17 and a processor 18, and determines the degree of deterioration of the battery 1 packaged with the main body 16. The timer 17 is composed of an appropriate timing device such as a clock generation circuit. The timer 17 starts operating manually or automatically when the main body 16 and the battery 1 are packed in a cardboard box, wrapping film, or other packaging material and placed inside the package 4, i.e., when the packaging process is completed, and generates a clock signal discretely or periodically. In another embodiment, the timer 17 may start operating when the package 4 containing the battery 1 and the determination device 10 is shipped from the factory.

[0015] The processor 18 synchronizes with the clock signal and calculates the deterioration level of the battery 1 based on the elapsed time since the timer 17 started operating and the ambient temperature history measured up to that elapsed time. The calculated deterioration level is stored in the memory 13 together with the elapsed time. The deterioration of the battery 1 is mainly caused by corrosion of the hydrogen storage alloy that constitutes the battery 1. The degree of deterioration can be determined because the magnetic susceptibility of the amount of metallic Ni in the battery 1 changes depending on the amount of corrosion. It is well known to those skilled in the art that the deterioration level changes depending on the elapsed time since the completion of the battery 1, the ambient temperature history, and the charge / discharge status of the battery. Therefore, the deterioration level of the battery is predicted based on the elapsed time since the completion of the battery 1 in an unused state and the magnetic susceptibility estimated based on the ambient temperature, which are stored in the memory.

[0016] In this embodiment, the ambient temperature history refers to the ambient temperature measured at predetermined intervals over time and sent to the microcontroller 12, recorded as a function of the elapsed time at that point, and means the change in the ambient temperature.

[0017] The memory 13 is made up of a non-volatile memory (EEPROM), and stores the deterioration degree sent from the processor 18 in association with the elapsed time, and accumulates the deterioration degree calculated for each elapsed time.

[0018] The communication interface 14 is capable of wired or wireless communication with a device 20 having a function 21 for predicting the life of the battery 1. The communication interface 14 reads the elapsed time and the degree of deterioration from the memory 13 and transmits them to the device 20.

[0019] The display unit 15 is a liquid crystal display. When a display button 19 provided on the main body 16 is operated, the display unit 15 displays on the screen the time elapsed since the packing or shipping of the battery 1 and the degree of deterioration. The determination device 10 is configured as described above.

[0020] Next, the operation of the determination device 10 will be described. When the determination device 10 and the battery 1 to be shipped are packed in packing material and the package 4 is completed (step S1), the timer 17 is started manually or automatically (step S2). Each time a predetermined time has elapsed since the timer 17 was started, the thermometer 11 outputs the temperature at the elapsed time to the processor (step S3). The processor 18 calculates the deterioration level of the battery 1 based on the elapsed time and the temperature history up to that time (step S4). Next, the microcomputer 12 stores the deterioration level in memory 13 in association with the elapsed time (step S5). In this way, the determination device 10 accumulates the deterioration level of the battery 1 as time passes since the battery 1 was packed.

[0021] Next, when the display button 19 is operated (step S6), the microcomputer 12 displays the amount of deterioration together with the elapsed time on the display unit 15 (step S7). In other embodiments, the display of the elapsed time may be omitted.

[0022] Next, when the package 4 is opened and the battery 1 is removed from the package 4 to install the battery 1 in the device 20 (step S8: YES), i.e., when the battery 1 is separated from the determination device 10, the timer 17 of the determination device 10 is stopped manually or automatically (step S9). Then, the microcomputer 12 reads the deterioration level and elapsed time from the memory 13 and waits for transmission, manually or automatically, via the communication interface 14 to the device 20 into which the enclosed battery 1 will be installed (or has already been installed) (step S10). When the device 20 receives the deterioration level and elapsed time from the determination device 10, the battery life prediction function 21 can predict the life of the battery 1 in the device 20 based on the received elapsed time and deterioration level.

[0023] Next, when the determination device 10 confirms that the elapsed time and the degradation level have been transmitted to the device 20 (step S10: YES), it resets the timer 17 and the memory 13 manually or automatically after a predetermined time has elapsed since transmission (step S11). Thus, the determination device 10 can prepare for packaging with a new battery. After the package 4 is opened, the determination device 10 continues to store this data in the memory 13 until the elapsed time and the degradation level are transmitted to the device 20 (step S10: NO).

[0024] On the other hand, if the microcomputer 12 determines that the package 4 is unopened (step S8: N), it returns to measuring the ambient temperature.

[0025] In another embodiment, the worker may visually check the elapsed time and the deterioration amount displayed on the display unit 15 and manually input them into the device 20.

[0026] In general, when a battery 1 is used in the same type of device, its effective battery life after use tends to differ depending on the level of deterioration at the start of use. In this disclosure, effective battery life refers to the period from the start of use of the battery until the battery's level of deterioration reaches a life threshold. For example, Figure 3 shows the increasing level of deterioration of Battery A, which was stored in an environment with variable ambient temperatures and then used for six months after factory shipment, and Battery B (dotted line), which was stored at a constant ambient temperature (30°C) and then used for six months after factory shipment. Both batteries are incorporated into the same device, and the operating conditions of the device are also the same. It can be seen that Battery A's level of deterioration is already higher than Battery B's level at the start of use. It can also be seen that Battery A's level of deterioration is more advanced at the start of use, and therefore it reaches the end of its life sooner than Battery B.

[0027] In addition, the storage period from the completion of packaging or shipment of a battery to the start of actual use, and the change in ambient temperature during storage or transportation, vary from battery to battery depending on demand and application, and are not uniform. Therefore, the degree of battery deterioration, which is one of the parameters for predicting battery life, varies depending on the storage period and the ambient temperature history during storage, even at the start of use.

[0028] Since the degree of deterioration of a battery at the start of use affects the length of its life after use, monitoring and storing the degree of deterioration of each battery up to the start of use and transmitting this information to the device in which each battery is used contributes to improving the accuracy of battery life predictions in that device, thereby preventing premature battery replacement, reducing battery waste and making it possible to use batteries effectively to the very end.

[0029] Furthermore, the degree of deterioration can be visually confirmed from the display, allowing the worker to roughly grasp the degree of deterioration of the battery before installing it in the device.

[0030] Furthermore, even if the storage period of the battery is the same, the deterioration level is calculated taking into account the ambient temperature history of the battery during storage, thereby improving the accuracy of battery life prediction for devices that use such batteries.

[0031] In the above embodiment, the deterioration level is quantified and displayed on the screen. However, in other embodiments, the display unit may display the elapsed time and deterioration level as a two-dimensional matrix code such as a QR code (registered trademark). In this case, the device incorporating the battery reads the two-dimensional matrix code to obtain data on the elapsed time and deterioration level. In this way, when a two-dimensional matrix code is used, the deterioration level can be input to the device quickly and accurately. [Explanation of symbols]

[0032] 1 Nickel-metal hydride battery 10 Battery deterioration degree determination device 11 Thermometer 12 Microcomputer 13. Memory 17 Timer

Claims

1. A battery deterioration level determination device that is packed with at least one nickel-metal hydride battery to be shipped, a timer that measures the elapsed time from the time the battery is packed with the nickel-metal hydride battery or from the time the battery is shipped; a temperature measuring means for measuring the ambient temperature of the nickel-metal hydride battery at predetermined intervals; a microcomputer that calculates a degree of deterioration of the nickel-metal hydride battery from the elapsed time and the history of the ambient temperature; a memory that stores the degree of deterioration together with the elapsed time; wherein the degree of deterioration is used to predict the life of a nickel-metal hydride battery depending on the usage environment.

2. The battery deterioration level determination device according to claim 1 , further comprising an output unit that outputs the elapsed time and the deterioration level to a lifespan prediction device.

3. The battery deterioration level determination device according to claim 1 , further comprising a display unit that displays the elapsed time and the deterioration level.

4. A method for determining the degree of deterioration of a nickel-metal hydride battery before use, comprising: measuring the time elapsed since the nickel-metal hydride battery was packaged or shipped; measuring the ambient temperature of the nickel-metal hydride battery at predetermined time intervals; calculating a degree of deterioration of the nickel-metal hydride battery from the elapsed time and the history of the ambient temperature; storing the degree of deterioration together with the elapsed time; A method comprising:

5. 5. The method according to claim 4, further comprising the step of outputting said degree of deterioration and said elapsed time to a means for predicting the life of said nickel-metal hydride battery.

6. The method according to claim 4 or 5, further comprising the step of displaying the elapsed time and the degree of deterioration.

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