JP5673470B2 - Charger - Google Patents

Description

  The present invention relates to a charging device that charges a rechargeable battery.

  Conventionally, in order to shorten the charging time of a rechargeable battery, a technique for performing charging at a voltage (overvoltage) higher than the upper limit voltage of the rechargeable battery is known (see Patent Document 1). In Patent Document 1, in a battery pack and its charger that perform constant current and constant voltage charging from trickle charging, the trickle charging is performed with a small current as in the past at the initial stage of trickle charging, When a low predetermined switching voltage is reached, charging is performed with a larger medium current than during trickle charging. As a result, when the end voltage is reached, switching to constant current (CC) charging is performed, the end voltage is set as the OCV voltage, and an overvoltage higher than the end voltage is applied between the charging terminals to perform ultra-rapid charging with a large current. When the charging current drops to a constant value level, switching to constant voltage (CV) charging is performed, an overvoltage is applied, and when the charging current further drops, the voltage drops to the end voltage. Thereby, while preventing the battery cell from being overcharged, a large amount of charge is injected to shorten the charging time.

JP 2007-288889 A

  However, in the above-described conventional technology, although charging can be performed in a short time compared with charging at a voltage lower than the normal upper limit voltage, the voltage is decreased stepwise after the overvoltage is applied. There is a problem that it takes a long time. In the above-described conventional technology, when the current supplied to the rechargeable battery starts to decrease while charging at a voltage higher than the upper limit voltage, the voltage is gradually reduced, and charging at a voltage higher than the upper limit voltage is performed. There is very little time to perform. Such control is performed in order to prevent overcharging, but in order to complete charging in a shorter time, it is necessary to continue a voltage state higher than the upper limit voltage for a longer time.

  The present invention has been made in view of such circumstances. When charging at a voltage higher than the upper limit voltage, the duration of the voltage state higher than the upper limit voltage is appropriately controlled to prevent overcharge. However, it aims at providing the charging device which can complete charge in a shorter time.

In order to achieve the above object, the present invention provides a charge control means for charging a rechargeable battery having a predetermined charge capacity, and an amount of electricity necessary to change the rechargeable battery from a state where the rechargeable battery capacity is empty to a fully charged state. A recording means for recording a correlation between the amount of fully charged electricity and the temperature of the rechargeable battery, the correlation recorded by the recording means when charging the rechargeable battery, and the rechargeable battery An estimation means for estimating a required amount of electricity, which is an amount of electricity required to bring the current rechargeable battery into a fully charged state, based on a current temperature and a current remaining amount of electricity of the rechargeable battery, and the charging The control means includes: a first charging means for charging the rechargeable battery at a voltage higher than an upper limit voltage that is an upper limit value of the open voltage of the rechargeable battery; and a second charging means for charging at a voltage equal to or lower than the upper limit voltage. Yes, and the recording means, the The ratio of the amount of electricity supplied until the rechargeable battery is fully charged during charging by the two charging means to the remaining capacity of the rechargeable battery increased by the charging by the second charging means with respect to the charging capacity. To calculate the amount of full charge electricity and to estimate the proportional relationship of the amount of full charge electricity in a temperature range that the rechargeable battery can take, and from the amount of full charge electricity at a predetermined temperature, The correlation is updated by estimating the full charge electricity amount at a temperature other than the temperature and recording the correlation, and the estimating means is configured to update the correlation when charging by the first charging means. The required amount of electricity is estimated based on the correlation updated during charging by two charging means, and the first charging means is estimated by the estimating means based on the updated correlation. It terminates the charging at the upper limit voltage higher and supplies the estimated the required quantity of electricity, characterized in that.

According to the present invention, when charging at a voltage higher than the upper limit voltage, the amount of electricity to be supplied (necessary amount of electricity) is estimated in advance, and charging is stopped when the supply of the necessary amount of electricity is completed. Therefore, the period during which charging is performed at a voltage higher than the upper limit voltage can be appropriately controlled, and charging of the rechargeable battery can be completed in a shorter time while preventing overcharging.

According to the present invention, since the amount of electricity supplied at the time of charging at a voltage equal to or lower than the upper limit voltage is divided by the ratio of the remaining amount of electricity increased by this charging, the fully charged electricity amount is calculated. If the amount of electricity is used, it is possible to know the amount of electricity necessary to bring the rechargeable battery into a fully charged state at that temperature, regardless of the remaining amount of electricity in the rechargeable battery.

According to the present invention, the proportional relationship of the full charge electricity amount at each temperature is estimated, and the full charge electricity amount at other temperatures is estimated using the proportional relationship. The amount of fully charged electricity in all temperature ranges can be known from the amount of charged electricity).

According to the present invention, when the open-circuit voltage of the rechargeable battery after charging at a voltage higher than the upper limit voltage exceeds the upper limit value, that is, when an overcharged state is reached, electricity is charged from the rechargeable battery until the upper limit value is reached. Since the battery is discharged, even if the battery is overcharged, the load on the rechargeable battery can be minimized and deterioration of the rechargeable battery can be prevented.

According to the present invention, since a plurality of correlations are recorded depending on the degree of deterioration of the rechargeable battery, the full charge electricity amount can be estimated according to the degree of deterioration of the rechargeable battery. By using this amount of fully charged electricity, it is possible to accurately know the amount of electricity required to make the rechargeable battery fully charged.

According to the present invention, since the rechargeable battery is mounted on a vehicle and used as a power source for driving the vehicle, use in a wide temperature range is expected by estimating the required amount of electricity based on the current temperature of the rechargeable battery. The charging control of the rechargeable battery for driving the vehicle can be appropriately performed.

It is a block diagram which shows the structure of the charging device 100 concerning embodiment. 3 is a block diagram illustrating a functional configuration of a control unit 110. FIG. It is a graph which shows an example of the full charge electricity amount-temperature map which the recording means 211 records. It is a graph which shows an example of a residual electric energy-open circuit voltage map. It is a graph which shows an example of a battery voltage-SOC map. 4 is a flowchart showing the operation of the charging device 100. 4 is a flowchart showing the operation of the charging device 100. 6 is a graph showing an example of a required charging time of the rechargeable battery 150. It is a graph which shows an example of the relationship between required charging time and battery temperature. It is a graph which shows an example of the relationship between the improvement rate of charge required time, and battery temperature.

  Exemplary embodiments of a charging method according to the present invention will be explained below in detail with reference to the accompanying drawings.

(Embodiment)
(Configuration of charging device 100)
FIG. 1 is a block diagram illustrating a configuration of a charging apparatus 100 according to the embodiment. The charging device 100 is a device that charges the rechargeable battery 150. The rechargeable battery 150 is a battery that can be used repeatedly by accumulating charges by charging. Here, the rechargeable battery 150 is mounted on a vehicle and used as a power source for driving the vehicle.
In FIG. 1, the rechargeable battery 150 and the charging device 100 are shown integrally, but the rechargeable battery 150 can be removed from the charging device 100 and used in any electrical product. In the present embodiment, the upper limit of the open circuit voltage (OCV) of the rechargeable battery 150 is 4.1V. The open circuit voltage is a voltage in a state where nothing is connected between the terminals of the rechargeable battery 150. Further, the charging capacity of the rechargeable battery 150 is 50 Ah.

Here, generally, in a normal charging device, CCCV charging (constant current-constant voltage charging) is performed at a voltage that does not exceed the upper limit of the open circuit voltage. That is, in a normal charging device, the rechargeable battery 150 is charged at 4.1 V or less. This is to avoid problems such as deterioration of the battery and reduction in safety due to overcharge.
On the other hand, charging apparatus 100 according to the present embodiment performs charging at a voltage exceeding the upper limit value of the open circuit voltage after controlling so that the open circuit voltage of rechargeable battery 150 after charging does not exceed the upper limit value. Thereby, the charging apparatus 100 shortens the time required for charging and performs charging in a short time.

  The charging device 100 is charged with a voltage exceeding the upper limit value of the open circuit voltage (hereinafter referred to as “rapid charge”), as well as charging with a voltage not exceeding the upper limit value of the open circuit voltage as usual (hereinafter, Also perform “normal charging”). If rapid charging is performed, the upper limit of the open-circuit voltage is exceeded temporarily, but this may lead to deterioration of the rechargeable battery 150. For this reason, it is efficient to use the quick charge as a quick charge function when going out or in an emergency, for example, and it is preferable for minimizing the deterioration of the rechargeable battery 150. It is desirable to limit the quick charge to, for example, about once a day. Although details will be described later, the rapid charging according to the present embodiment is highly effective in charging at a low temperature or charging with a large current.

  In the following description, unless otherwise specified, charging is performed with the same current as the charging capacity of the rechargeable battery 150 (that is, 50 A), and the current that can be supplied to the rechargeable battery 150 is 0.5 A. Assume that charging is completed at the time (1C_0.5Acut charging).

  The charging device 100 includes a charging power source 102, an ammeter 103, a voltmeter 104, a temperature sensor 105, a resistor 106, a switch 107, and a control unit (ECU) 110. The charging power supply 102 is configured by a power supply circuit and supplies charging power to the rechargeable battery 150. The ammeter 103 measures the amount of current supplied to the rechargeable battery 150 and the amount of current discharged from the rechargeable battery 150. The voltmeter 104 measures the battery voltage of the rechargeable battery 150. The temperature sensor 105 measures the temperature of the rechargeable battery 150. The resistor 106 and the switch 107 are used for discharging from the rechargeable battery 150.

The control unit 110 includes a CPU, a ROM that stores and stores a control program, a RAM as an operation area of the control program, an interface unit that interfaces with peripheral circuits and the like.
Control unit 110 controls charging of rechargeable battery 150 based on output values of ammeter 103, voltmeter 104, temperature sensor 105, and the like. Specifically, the control unit 110 controls the amount of current supplied from the charging power source 102 to the rechargeable battery 150, the timing for terminating charging, and the like.

FIG. 2 is a block diagram illustrating a functional configuration of the control unit 110. The control unit 110 executes the control program to realize a recording unit 211, an estimation unit 212, a charge control unit 213 (first charging unit 213a and second charging unit 213b), and a discharge control unit 214.
The recording unit 211 stores the amount of electricity required to change the rechargeable battery 150 having a predetermined charge capacity from the empty rechargeable battery capacity to the fully charged state (hereinafter referred to as “full charge electricity amount”). Record the correlation with temperature. In general, it is known that the battery capacity of the rechargeable battery 150 decreases because the internal resistance increases as the temperature decreases. As the battery capacity changes with temperature, the amount of electricity fully charged in the rechargeable battery 150 changes depending on the temperature. The recording unit 211 records the correlation between the full charge electricity amount and the temperature of the rechargeable battery 150 as a full charge electricity amount-temperature map as shown in FIG.

  FIG. 3 is a graph showing an example of a full charge electricity amount-temperature map recorded by the recording unit 211. A correlation diagram between the amount of fully charged electricity and temperature as shown in FIG. 3 is hereinafter referred to as a “map”. In the graph of FIG. 3, the vertical axis represents the full charge electricity amount, and the horizontal axis represents the temperature of the rechargeable battery 150. Also, in FIG. 3, reference numeral 301 indicates a correlation when the rechargeable battery 150 is new, and reference numeral 302 indicates a correlation of the rechargeable battery 150 whose battery capacity has been reduced after repeated use for a certain period. As shown in FIG. 3, the battery capacity of the rechargeable battery 150 decreases as the temperature decreases, and the amount of fully charged electricity decreases.

  Further, it is known that the battery capacity of the rechargeable battery 150 is reduced by repeatedly charging and discharging while being used as a battery. For this reason, it can be seen that the state in which the rechargeable battery 150 indicated by reference numeral 302 is used for a certain period of time is smaller than the state when the rechargeable battery 150 is new as indicated by reference numeral 301 as a whole. Each time the rechargeable battery 150 is charged, the recording unit 211 records the amount of fully charged electricity and temperature, estimates a correlation suitable for the current state of the rechargeable battery 150, and updates the map.

  Returning to the description of FIG. 2, the estimation unit 212 calculates the correlation recorded by the recording unit 211 when charging the rechargeable battery 150, the current temperature of the rechargeable battery 150, and the current remaining amount of electricity of the rechargeable battery 150. Based on this, the amount of electricity required to make the current rechargeable battery 150 fully charged (hereinafter referred to as “necessary amount of electricity”) is estimated.

  Specifically, the estimation unit 212 selects a map suitable for the current state of the rechargeable battery 150 from the correlation map recorded by the recording unit 211, and the full charge corresponding to the current temperature of the rechargeable battery 150. Read the amount of electricity. Then, the estimation means 212 estimates the required amount of electricity by subtracting the current remaining amount of electricity of the storage battery 150 from the fully charged amount of electricity.

The charging control unit 213 controls the charging power source 102 to charge the rechargeable battery 150 with a voltage higher than the upper limit value of the open voltage of the rechargeable battery 150, and the required amount of electricity estimated by the estimating unit 212 is charged to the rechargeable battery 150. The first charging means 213a that terminates the charging of the rechargeable battery 150 is provided. Specifically, the first charging unit 213a controls the charging power source 102 so that a voltage (for example, 4.2V) higher than the upper limit value of the open voltage of the rechargeable battery 150 becomes the upper limit voltage. Charge the battery. During this time, the first charging unit 213a accumulates the amount of power supplied to the rechargeable battery 150, and stops the power supply from the charging power source 102 when the required amount of power is reached. In this way, the necessary charge amount is estimated in advance, and charging is stopped at the timing when the necessary charge amount is supplied, so even if charging is performed at a voltage higher than the upper limit value of the open voltage of the rechargeable battery 150, overcharge is performed. Can be prevented.
The charging control unit 213 includes a second charging unit 213 b that charges the rechargeable battery 150 with a voltage that is equal to or lower than the upper limit value of the open voltage of the rechargeable battery 150 by controlling the charging power supply 102. Specifically, the second charging unit 213b controls the charging power source 102 so that a voltage equal to or lower than the upper limit value of the open voltage of the rechargeable battery 150 (for example, 4.1 V) becomes the upper limit voltage. Charge the battery.

  When the open circuit voltage of the rechargeable battery 150 after charging exceeds the upper limit value, the discharge control means 214 discharges electricity from the rechargeable battery 150 until it becomes equal to or lower than the upper limit value. Specifically, the discharge control means 214 monitors the open voltage of the rechargeable battery 150 after charging, and when the open voltage is higher than 4.1 V, closes the switch 107 so that a current flows through the resistor 106. As a result of such discharge, when the open-circuit voltage becomes 4.1 V or less, the discharge control means 214 opens the switch 107 and stops the discharge. In addition, when the voltage of the rechargeable battery 150 decreases too much as a result of the discharge by the discharge control means 214 (for example, when the open circuit voltage becomes 4.08 V or less), the rechargeable battery 150 is charged again. It may be.

(Details of map creation method)
Next, details of a method for creating the fully charged electricity amount-temperature map shown in FIG. 3 will be described. As described above, the battery capacity of the rechargeable battery 150 decreases due to deterioration over time due to repeated use. For this reason, the recording unit 211 performs discharge from the fully charged state in order to grasp the deterioration state of the rechargeable battery 150 prior to the creation of the map shown in FIG. 3, and maps the remaining electricity amount and the open circuit voltage value. Record as.

FIG. 4 is a graph showing an example of a remaining power amount-open voltage map. In the graph of FIG. 4, the vertical axis represents battery voltage, and the horizontal axis represents capacity (discharge flow rate). In FIG. 4, reference numeral 401 indicates a correlation when the rechargeable battery 150 is new (battery capacity C ₁ ), and reference numeral 402 indicates a correlation when the battery capacity is reduced to C ₂ ( _{C 1>} C 2), show the sign 403 is the correlation when the battery capacity is further reduced to _{C 3 (C 2> C 3} ). In addition, you may perform discharge in the case of producing the map of FIG. FIG. 4 is a map at a discharge temperature of 25 ° C.

From the map as shown in FIG. 4, it is possible to know what deterioration state the current rechargeable battery 150 is in. For example, if you battery capacity _{C 4} discharged from the fully charged state _{(C 3> C} 4), the battery voltage in the new state (battery capacity _{C 1)} becomes _{V 1.} When the battery capacity is C ₂ , that is, when the capacity is deteriorated by C ₂ / C ₁ × 100%, the battery voltage when C _{4 is} discharged from the fully charged state is V ₂ (V ₁ > V ₂ ). When the battery capacity is C ₃ , that is, when the capacity is deteriorated by (C ₃ / C ₁ ) × 100%, the battery voltage when C _{4 is} discharged from the fully charged state is V ₃ (V ₂ > V ₃ ).

The recording unit 211 further converts the capacity (discharge flow rate) of the map of FIG. 4 into SOC (state of charge) and creates a battery voltage-SOC map as shown in FIG.
FIG. 5 is a graph showing an example of a battery voltage-SOC map. In the graph of FIG. 5, the vertical axis represents battery voltage, and the horizontal axis represents SOC (%). In FIG. 5, reference numeral 501 indicates a correlation (battery capacity C ₁ ) when the rechargeable battery 150 is new, and reference numeral 502 indicates a correlation when the battery capacity is reduced to C ₂ ( _{C 1>} C 2), show the sign 503 is the correlation when the battery capacity is further reduced to _{C 3 (C 2> C 3} ).

The current SOC of the rechargeable battery can be known from the map as shown in FIG. For example, when the battery voltage is V ₄ in a rechargeable battery whose battery capacity is reduced to C ₂ , the SOC is S ₄ (%) (see the dotted line in FIG. 5).
4 and FIG. 5, it is preferable to actually create the map by changing the full charge capacity temperature in increments of, for example, 5% of the full charge capacity change. Thereby, the current battery deterioration state can be known by one discharge operation, and the current SOC can be obtained from any voltage. For example, even in the case of indefinite amount of degradation (17Ah, 31Ah, etc. in some cases), due to the SOC-OCV relationship of various degraded batteries, the capacity discharged from full charge and the open-circuit voltage at that time agree in the degradation state Since there is only one map to be performed, the deterioration state can be grasped.

  Thus, using the state of charge of the rechargeable battery 150 ascertained from FIGS. 4 and 5, the recording unit 211 creates the full charge electricity amount-temperature map shown in FIG. 3 shown in FIG. When the recording unit 211 performs charging (normal charging) below the upper limit value of the open-circuit voltage, the remaining amount of the rechargeable battery 150 is increased by the normal charging to the amount of electricity supplied until the rechargeable battery 150 is fully charged. The full charge electricity amount is calculated by dividing by the ratio of the electricity amount to the charge capacity.

Specifically, the recording means 211 is
1. Charging state (SOC) of rechargeable battery 150 at the start of charging
2. 2. Electricity supplied during charging Record the temperature of the rechargeable battery 150 during charging. Above 1. Are values obtained from FIGS. 4 and 5.

Further, the recording unit 211 estimates the proportional relationship of the full charge electricity amount in the temperature range that the rechargeable battery can take, and calculates the full charge electricity amount at a temperature other than the predetermined temperature from the full charge electricity amount at the predetermined temperature. The correlation may be recorded by estimation. This is because the amount of fully charged electricity is substantially proportional to the temperature.
It should be noted that the proportional distribution value due to temperature may also be sequentially updated using the actual measurement value because the ratio may change due to deterioration of the rechargeable battery 150.

(Operation of charging device 100)
Next, the operation of the charging apparatus 100 will be described.
6 and 7 are flowcharts showing the operation of the charging apparatus 100. In the flowchart of FIG. 6, the charging device 100 first determines whether or not the current charging is rapid charging (step S601). Whether or not quick charging is performed is determined by, for example, setting input from the user, the state of the rechargeable battery 150, or the like. When the current charging is rapid charging (step S601: Yes), the process proceeds to step 408 in FIG. 7 (connector A).

  On the other hand, when the current charging is not rapid charging (step S601: No), charging device 100 performs normal charging. The charging device 100 detects the current charging state (charging start SOC) of the charging device 100 and the current temperature (battery temperature) of the rechargeable battery 150 by the recording unit 311 (step S602). Next, the charging device 100 supplies power from the charging power source 102 to the rechargeable battery 150 to charge the rechargeable battery 150 (step S603). During this time, the recording unit 311 integrates the amount of current supplied to the rechargeable battery 150 based on the output value from the ammeter 103.

The charging device 100 returns to step S603 and continues charging the rechargeable battery 150 until the amount of current (charging current) flowing from the charging power source 102 to the charging value 150 becomes 0.5 A or less (step S604: No). To do. Then, when the charging current becomes 0.5 A or less (step S604: Yes), the charging apparatus 100 stops charging as charging of the charging value 150 is completed (step S605). The recording unit 211 calculates a necessary amount of electricity based on the integrated current amount and the charging start SOC (step S606), records the calculated necessary amount of electricity in association with the temperature, and updates the map (step S607). The process according to this flowchart ends. At this time, the recording unit 211 may estimate the required amount of electricity at a temperature other than the current temperature of the rechargeable battery 150 using the flow rate as calculated in step S606 and use it for updating the map.
The above is the processing during normal charging.

  Turning to the description of FIG. 7, the process at the time of quick charging will be described. In step S601 of FIG. 6, when the current charging is rapid charging (step S601: Yes, connector A), the charging device 100 determines the current charging state (remaining amount of electricity) of the charging device 100 and the current charging. The battery temperature of the battery 150 is detected (step S608). Next, the charging device 100 uses the estimation unit 212 to estimate the required charge amount for the current charging from the information and map detected in step S608 (step S609).

Subsequently, the charging device 100 supplies power from the charging power source 102 to the rechargeable battery 150 to charge the rechargeable battery 150 (step S610). During this time, the charging control unit 213 integrates the amount of current supplied to the rechargeable battery 150 based on the output value from the ammeter 103. The charging device 100 returns to step S610 to charge the rechargeable battery 150 until the integrated value of the amount of current supplied from the charging power supply 102 to the charge value 150 becomes equal to or greater than the required amount of electricity (step S611: No). continue. When the accumulated value is more than necessary quantity of electricity (step S611: Yes), charging device 100 stops the charging as the charging of the charging value 150 has been completed (step S612).

Thereafter, the charging device 100 determines whether or not the open circuit voltage (OCV) of the rechargeable battery 150 after charging is 4.1 V or less (step S613), and when it is 4.1 V or less (step S613: No). That is, when the overcharge state is not established, the process according to this flowchart is terminated as it is (connector B).
On the other hand, when the open circuit voltage is not 4.1 V or less (step S613: Yes), the rechargeable battery 150 is discharged by the discharge control means 214, assuming that it is in an overcharged state (step S614). In addition, when the voltage of the rechargeable battery 150 decreases too much as a result of the discharge by the discharge control means 214 (for example, when the open circuit voltage becomes 4.08 V or less), the rechargeable battery 150 is charged again. It may be. The charging at this time is performed by the normal charging shown in FIG.
As described above, the charging device 100 charges the rechargeable battery 150.

  FIG. 8 is a graph showing an example of the time required for charging the rechargeable battery 150. In FIG. 8, the horizontal axis represents the elapsed time from the start of charging, the left axis represents the battery voltage of the rechargeable battery 150, and the right axis represents the charging capacity of the rechargeable battery 150. In FIG. 8, the solid line indicates the measured value (VA, IA) in the charging method (rapid charging) according to the present embodiment, and the dotted line indicates the measurement in the conventional charging method (normal charging). It is a value (VB, IB).

In the charging method according to the present embodiment, the upper limit value of the battery voltage is 4.2 V as indicated by reference numeral VA, and the time required to charge to a predetermined charging capacity C _X Ah is as indicated by reference numeral IA. the T _1. On the other hand, in the charging method according to the prior art, the upper limit value of the battery voltage is 4.1 V (upper limit value of the open-circuit voltage) as indicated by reference numeral VB, and the time required to charge to a predetermined charge capacity C _X Ah is: As indicated by the symbol IB, T ₂ is obtained (T ₁ <T ₂ ). As described above, in the charging method according to the present embodiment, the time required for charging can be significantly shortened as compared with the charging method according to the prior art.

  FIG. 9 is a graph showing an example of the relationship between the required charging time and the battery temperature. In FIG. 9, the vertical axis represents the required charging time, and the horizontal axis represents the battery temperature. In addition, a solid line indicates a measured value in the charging method (rapid charging) according to the present embodiment, and a dotted line indicates a measured value in the conventional charging method. As shown in FIG. 9, it can be seen that, particularly when the battery temperature is low, the charging method according to the present embodiment can significantly reduce the charging time.

  FIG. 10 is a graph showing an example of the relationship between the improvement rate of the required charging time and the battery temperature, and the difference between the required time in the charging method according to the present embodiment shown in FIG. 9 and the required time in the conventional charging method. Is divided by the required time in the charging method. As shown in FIG. 10, it can be seen that the charging time can be greatly shortened by the charging method according to the present embodiment.

  In the present embodiment, the map is created by calculating the amount of fully charged electricity from the amount of current supplied during charging, but the map creation method is not limited to this. For example, the relationship between the required electricity amount and the battery temperature for each remaining electricity amount (for example, 40%, 45%, 50%,..., Etc.) of the storage battery 150 may be mapped. In this case, a map used for the current charging is selected from the remaining amount of electricity at the time of charging, and the charging period is controlled by reading the required amount of electricity from the battery temperature at the time of charging.

  Moreover, although the rechargeable battery 150 in the present embodiment is mounted on a vehicle and used as a power source for driving the vehicle, the type of the rechargeable battery is not limited thereto. For example, the present invention can be applied to rechargeable batteries for various industrial machines such as mobile phones and personal computers, but is more preferably applied to rechargeable batteries for driving vehicles that are expected to be used in a wide temperature range.

  As described above, the charging device 100 according to the present embodiment estimates the amount of electricity to be supplied (necessary amount of electricity) in advance when charging at a voltage higher than the upper limit voltage, and the necessary amount of electricity. When the supply of is completed, charging is stopped. Thereby, it is possible to appropriately control the period during which charging is performed at a voltage higher than the upper limit voltage, and it is possible to complete charging of the rechargeable battery in a shorter time while preventing overcharging.

  In addition, the charging device 100 calculates the fully charged electricity amount by dividing the amount of electricity supplied during normal charging by the ratio of the remaining electricity amount increased by charging. For this reason, if the amount of fully charged electricity is used, the amount of electricity necessary for making the rechargeable battery fully charged at the temperature can be known regardless of the remaining amount of electricity of the rechargeable battery.

  Moreover, the charging device 100 estimates the proportional relationship of the full charge electricity amount at each temperature, and estimates the full charge electricity amount at other temperatures using the proportional relationship. Thereby, the amount of full charge electricity in all temperature zones can be known by one charge (the amount of full charge electricity at one temperature).

  Moreover, the charging device 100 discharges electricity from a rechargeable battery until it becomes below an upper limit, when the open circuit voltage of the rechargeable battery after charge exceeds the upper limit, ie, when it will be in an overcharge state. Thereby, even if it becomes an overcharged state, the load to a rechargeable battery can be minimized and deterioration of a rechargeable battery can be prevented.

  DESCRIPTION OF SYMBOLS 100 ... Charging apparatus, 102 ... Charging power supply, 103 ... Ammeter, 104 ... Voltmeter, 105 ... Temperature sensor, 106 ... Resistance, 107 ... Switch, 110 ... Control part (ECU), 211 ... recording means, 212 ... estimating means, 213 ... charge control means, 213a ... first charging means, 213b ... second charging means, 214 ... discharge control means.

Claims (4)

Charging control means for charging a rechargeable battery having a predetermined charging capacity;
A recording means for recording a correlation between a full charge electricity amount, which is an amount of electricity required to change the rechargeable battery capacity from an empty state to a fully charged state, and a temperature of the rechargeable battery;
When charging the rechargeable battery, the current rechargeable battery is filled based on the correlation recorded by the recording means and the current temperature of the rechargeable battery and the current remaining amount of electricity of the rechargeable battery. An estimation means for estimating a necessary amount of electricity that is necessary to obtain a charged state, and
The charging control means includes a first charging means for charging the rechargeable battery at a voltage higher than an upper limit voltage that is an upper limit value of the open voltage of the rechargeable battery, and a second charging means for charging at a voltage equal to or lower than the upper limit voltage. It has a door,
In the charging by the second charging means, the recording means increases the amount of electricity supplied until the rechargeable battery is fully charged by charging by the second charging means. Dividing the amount of charge to the charge capacity, calculating the full charge electricity amount, estimating a proportional relationship of the full charge electricity amount in a temperature range that can be taken by the rechargeable battery, and obtaining the full charge amount at a predetermined temperature. From the amount of charged electricity, update the correlation by estimating the fully charged amount of electricity at a temperature other than the predetermined temperature and recording the correlation,
The estimation means estimates the required amount of electricity based on the correlation updated at the time of charging by the second charging means at the time of charging by the first charging means,
The first charging unit ends charging at a voltage higher than the upper limit voltage when the necessary amount of electricity estimated by the estimating unit is supplied based on the updated correlation.
A charging device characterized by that. When the open voltage of the rechargeable battery after being charged by the first charging means exceeds the upper limit value, the battery pack further includes discharge control means for discharging electricity from the rechargeable battery until the upper limit value is reached. The charging device according to claim 1 , wherein: It said recording means, the charging device according to claim 1 or 2, characterized in that to record a plurality of the correlation by the degree of deterioration of the rechargeable battery. The charging device according to any one of claims 1 to 3 , wherein the rechargeable battery is mounted on a vehicle and used as a power source for driving the vehicle.

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