Charging method

Abstract

To provide a technique capable of reducing charging time.SOLUTION: A charging method includes the steps of: determining whether or not rapid charging is performed; when determined that rapid charging is performed, determining whether or not a degree of decrease in capacity of a battery is equal to or greater than a predetermined first threshold value or whether or not the degree of increase in internal resistance of a cell of the battery is equal to or greater than a predetermined second threshold value; when determined that the degree of decrease in the capacity of the battery is equal to or greater than the first threshold, increasing temperature of the battery according to the degree of decrease in the capacity of the battery or when determined that the degree of increase in the internal resistance of the battery is equal to or greater than the second threshold, increasing the temperature of the battery according to the degree of increase in the internal resistance of the battery.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a charging method. [Background technology]

[0002] For example, a technique is known in which a current specified according to the deterioration state of a battery is applied during charging, as described in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-86583 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the battery is degraded, there is a limit to how much the charging time can be reduced even if the charging current is adjusted, so there has been a demand for technology that can reduce the charging time. [Means for solving the problem]

[0005] The present disclosure has been made to solve the above-mentioned problems, and can be realized in the following forms.

[0006] According to one embodiment of the present disclosure, there is provided a charging method, which includes the steps of: determining whether or not quick charging is being performed; determining whether or not a degree of decrease in capacity of a battery is equal to or greater than a predetermined first threshold value or whether or not a degree of increase in internal resistance of a cell of the battery is equal to or greater than a predetermined second threshold value when quick charging is determined; and increasing a temperature of the battery according to a degree of decrease in capacity of the battery when it is determined that a degree of decrease in capacity of the battery is equal to or greater than the first threshold value, or increasing a temperature of the battery according to a degree of increase in internal resistance of a cell of the battery when it is determined that a degree of increase in internal resistance of a cell of the battery is equal to or greater than the second threshold value. According to this charging method, when the degree of decrease in the battery capacity is equal to or greater than the first threshold, or when the degree of increase in the internal resistance of the battery cell is equal to or greater than the second threshold, that is, when the battery is degraded, the temperature of the battery is increased, thereby decreasing the internal resistance of the battery and charging the battery, thereby reducing the charging time.

[0007] The present disclosure can be realized in various forms, for example, as a charging device, a charging system, or the like. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an overview of a charging system. [Diagram 2] 4 is a flowchart showing an example of a temperature rise control process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A. First embodiment: 1 is a schematic diagram showing an overview of a charging system 100 according to this embodiment. The charging system 100 includes a battery unit 10 and a charging device 20. The charging system 100 is a system that charges a battery 11 of the battery unit 10 mounted on a vehicle, for example.

[0010] The battery unit 10 has a battery 11, a sensor 12, and a heating device 13. The sensor 12 detects the output current, output voltage, and temperature of the battery 11, as well as the current and voltage applied to the battery 11. The heating device 13 is a device that heats the battery 11, and is, for example, a heater.

[0011] The charging device 20 is composed of a computer including a central processing unit (CPU), RAM, ROM, etc., and realizes control of the power supplied to the battery 11 and control of the heating device 13 by executing a program preinstalled in a storage area of ​​the charging device 20. However, a part or all of these controls may be realized by a hardware circuit. In this embodiment, the charging device 20 calculates the internal resistance of the battery 11 using information detected by the sensor 12.

[0012] 2 is a flowchart showing an example of a temperature rise control process. The temperature rise control process is a process in which the charging device 20 raises the temperature of the battery 11 according to the degree of deterioration of the battery 11. In this embodiment, this process is executed when charging of the battery 11 starts.

[0013] In step S100, the charging device 20 determines whether or not quick charging is being performed. For example, the charging device 20 determines that quick charging is being performed when the voltage applied to the battery 11 detected by the sensor 12 is equal to or higher than a predetermined threshold value, or when a signal indicating quick charging is received. If quick charging is being performed, the charging device 20 proceeds to the process of step S110. On the other hand, if quick charging is not being performed, the charging device 20 ends the temperature rise control process.

[0014] In step S110, the charging device 20 judges whether the degree of decrease in the capacity of the battery 11 is equal to or greater than a predetermined first threshold, or whether the degree of increase in the internal resistance of the cell of the battery 11 is equal to or greater than a predetermined second threshold. In this embodiment, the degree of decrease in the capacity of the battery 11 is the ratio of the capacity of the battery 11 at the most recent full charge to the capacity of the battery 11 at the full charge when the battery 11 is new. The first threshold is a value determined experimentally in advance, and is a value indicating that the battery 11 has deteriorated to such an extent that the time required to charge the battery 11 is equal to or greater than a predetermined threshold time. In this embodiment, the degree of increase in the internal resistance of the battery 11 is the ratio of the internal resistance of the battery 11 to the internal resistance of the battery 11 at the time of new. The second threshold is a value determined experimentally in advance, and is a value indicating that the battery 11 has deteriorated to such an extent that the time required to charge the battery 11 is equal to or greater than a predetermined threshold time. That is, in step S110, the charging device 20 judges whether the degree of deterioration of the battery 11 is equal to or greater than a predetermined threshold.

[0015] If the degree of decrease in the capacity of the battery 11 is equal to or greater than the first threshold, or if the degree of increase in the internal resistance of the cell of the battery 11 is equal to or greater than the second threshold, the charging device 20 proceeds to the process of step S120. On the other hand, if the degree of decrease in the capacity of the battery 11 is less than the first threshold, or if the degree of increase in the internal resistance is less than the second threshold, the charging device 20 ends the temperature rise control process.

[0016] In step S120, the charging device 20 determines a target temperature increase amount. More specifically, the charging device 20 determines the temperature increase amount of the battery 11 according to the degree of decrease in capacity of the battery 11 when it is determined that the degree of decrease in capacity of the battery 11 is equal to or greater than a first threshold, or according to the degree of increase in internal resistance when it is determined that the degree of increase in internal resistance is equal to or greater than a second threshold.

[0017] The charging device 20 determines the target temperature rise amount based on, for example, a map or function that defines the relationship between the degree of capacity decrease and the temperature rise amount of the battery 11, or a map or function that defines the relationship between the degree of increase in internal resistance and the temperature rise amount. The temperature rise amount when the degree of capacity decrease of the battery 11 is large is larger than the temperature rise amount when the degree of capacity decrease of the battery 11 is small. Also, the temperature rise amount when the degree of increase in internal resistance is large is larger than the temperature rise amount when the degree of increase in internal resistance is small. That is, the charging device 20 makes the temperature rise amount when the degree of deterioration of the battery 11 is large larger than the temperature rise amount when the degree of deterioration of the battery 11 is small.

[0018] In step S130, the charging device 20 determines whether the temperature of the battery 11 has risen by the target temperature rise amount or more determined in step S120. If the temperature rise of the battery 11 is equal to or more than the target temperature rise amount, the charging device 20 ends the temperature rise control process. On the other hand, if the temperature rise of the battery 11 is less than the target temperature rise amount, the charging device 20 performs a temperature rise process in step S140 to control the temperature rise device 13 to raise the temperature of the battery 11, and returns to the process of step S130. In other words, the charging device 20 repeats the processes of steps S130 to S140 until the temperature of the battery 11 rises by the target temperature rise amount or more.

[0019] According to the charging method of the present embodiment described above, when the degree of decrease in the capacity of the battery 11 is equal to or greater than the first threshold value, or when the degree of increase in the internal resistance of the cell of the battery 11 is equal to or greater than the second threshold value, that is, when the battery 11 is deteriorated, the charging device 20 increases the temperature of the battery 11, thereby decreasing the internal resistance of the battery 11 and performing charging. As a result, the charging time can be reduced.

[0020] B. Other embodiments: (B1) In the above-described embodiment, the charging device 20 controls the heating device 13 to heat the battery 11 as the heating process in step S140. However, the charging device 20 may control a cooling device (not shown) of the battery 11 to heat the battery 11.

[0021] (B2) In the above-described embodiment, the degree of decrease in the capacity of the battery 11 is the ratio of the capacity of the battery 11 when it was most recently fully charged to the capacity of the battery 11 when it was brand new. However, the degree of decrease in the capacity of the battery 11 may be, for example, the amount of decrease in battery capacity per unit time, or the ratio of the capacity of the battery 11 when it was fully charged to the capacity of the battery 11 when it was brand new, which is estimated from the output voltage of the battery 11, or the like.

[0022] (B3) In the above-described embodiment, the degree of increase in the internal resistance of the battery 11 is the ratio of the internal resistance of the battery 11 to the internal resistance of the battery 11 when it is new. However, the degree of increase in the internal resistance may be, for example, the amount of increase in the internal resistance per unit time.

[0023] The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in the embodiments corresponding to the technical features in each form described in the Summary of the Invention column can be appropriately replaced or combined in order to solve the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0024] 10: battery unit, 11: battery, 12: sensor, 13: heating device, 20: charging device, 100: charging system

Claims

[Claim 1] A charging method, comprising: A step of determining whether or not quick charging is being performed; When it is determined that the charging is rapid, determining whether or not a degree of decrease in the capacity of the battery is equal to or greater than a predetermined first threshold, or whether or not a degree of increase in the internal resistance of the cell of the battery is equal to or greater than a predetermined second threshold; a step of increasing a temperature of the battery in accordance with a degree of decrease in capacity of the battery when it is determined that the degree of decrease in capacity of the battery is equal to or greater than the first threshold, or increasing a temperature of the battery in accordance with a degree of increase in internal resistance of cells of the battery when it is determined that the degree of increase in internal resistance of cells of the battery is equal to or greater than the second threshold.

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