JP2002171685A - Battery charger - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a battery charger capable of preventing a reduction in life by suppressing variation in temperature occurring in a battery when performing quick charging. SOLUTION: When a temperature difference between a plurality of points of the battery 11 detected by temperature detecting means 21 and 22 for detecting a temperature of a plurality of points of the battery 11 becomes larger than a predetermined value, a charge control means 13 detects the temperature difference. Is controlled to be within a predetermined value, thereby suppressing the temperature variation occurring in the battery when performing quick charging,
Reduces variation in capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery charger for use in electric vehicles, hybrid vehicles, and the like.

[0002]

2. Description of the Related Art For example, a battery such as Ni-MH (nickel-metal hydride) used in an electric vehicle has a low charging rate (charging rate (C): 1 (C) in one hour in a garage at home. Is a current value at which the battery can be fully charged in 2 minutes, 2 (C) is a current value at which the battery can be fully charged in 30 minutes, and 0.5 (C) is a current value at which the battery can be fully charged in 2 hours.
(C), that is, a current value at which a battery can be fully charged in 5 hours) is usually charged overnight.
When it is necessary to charge the battery when going out, it is convenient if the vehicle can be charged quickly while the vehicle is stopped for a meal or the like while going out.

[0003] Due to such advantages, when attempting to rapidly charge a battery such as Ni-MH, the calorific value increases and an excessive temperature rise occurs, or excessive O2 gas or H2 gas is generated during charging. Internal pressure may increase. For this reason, it has been proposed to cool the battery by flowing the coolant through the battery (Japanese Patent Application Laid-Open No. 9-199186).

[0004] Further, some batteries have a configuration as shown in FIG. The battery 79 includes a plurality of modules, specifically, a module having ten cells (not shown) as one unit.
More specifically, it is configured by arranging 24 modules, and includes a cooling device 80 for absorbing heat generated during charging of each of the modules M1 to M24. The cooling device 80 includes a refrigerant channel 81 for circulating the refrigerant, a radiator 82 for releasing heat from the refrigerant flowing through the refrigerant channel 81, and a pump 83 for sucking and discharging the refrigerant cooled by the radiator 82 in the refrigerant channel 81. And Here, the refrigerant flow path 81 has a plurality of branch flow paths R1 to R1 on the downstream side of the pump 83.
The coolant flowing through each of the branch flow paths R1 to R12 cools the two modules forming the set and then joins to return to the radiator 82.

[0005]

By the way, the refrigerant which flows through each branch flow path and cools the battery has no problem in the case of normal charging, but in the case of rapid charging, particularly, each branch flow path includes a plurality of modules. When the branch flow path is long as in FIG. 7 for cooling, the temperature difference between the upstream side and the downstream side of the branch flow path may increase due to heat absorption, and as a result, the flow direction of the branch flow path of the module , A large temperature difference may occur between the upstream side and the downstream side.

For example, one branch flow path R12 shown in FIG.
Modules M23 and M cooled by the refrigerant flowing through
24, the point of time when the battery is fully charged when quick charging is performed (that is, the remaining battery charge SOC = 100)
(% Point), the temperature difference of the refrigerant between the upstream side and the downstream side of the branch flow path R12 becomes 12 ° C. due to heat absorption, and as a result, as shown in FIG. (At time = 0) at the time when the temperature difference ΔT between the upstream end position and the downstream end position of the module in the flow direction of the branch flow channel was 0 at the time when the module is fully charged, 17 ° C.
Becomes a large value that cannot be ignored. If the upstream temperature and the downstream temperature vary in the module as described above, the capacity also varies, and the life is shortened due to overdischarge and overcharge.

Accordingly, an object of the present invention is to provide a battery charging device capable of preventing a reduction in the life of a battery by suppressing a variation in temperature occurring in the battery during rapid charging.

[0008]

In order to achieve the above object, a battery charging device according to a first aspect of the present invention includes a battery (for example, the battery 11 in FIG. 1 in the embodiment).
Charging means for charging the battery (for example, the charger 12 in FIG. 1 in the embodiment); and charging control means for controlling the charging operation of the battery by the charging means (for example, the ECU 13 in FIG. 1 in the embodiment). Temperature detecting means for detecting the temperature of a plurality of locations of the battery (for example, the battery temperature detecting units 21 and 22 of FIG. 1 in the embodiment)
The charging control means, when the temperature difference at a plurality of locations of the battery detected by the temperature detecting means is larger than a first predetermined value, the temperature difference is within a second predetermined value It is characterized by including a temperature control means (for example, the temperature control unit 24 in FIG. 1 in the embodiment) for controlling the temperature to be controlled.

Thus, when the temperature difference between the plurality of locations of the battery detected by the temperature detecting means becomes larger than the first predetermined value, the temperature control means controls the temperature difference to be within the second predetermined value. Since the control is performed, the variation in the temperature generated in the battery during the quick charging is suppressed, and the variation in the capacity is suppressed.

According to a second aspect of the present invention, there is provided the battery charging apparatus according to the first aspect, further comprising a cooling means (for example, the cooling device shown in FIG. 1 in the embodiment) for cooling the battery with a refrigerant. The control means reverses the traveling direction of the refrigerant in the battery by the cooling means, thereby controlling the temperature difference to be within a predetermined value.

With this arrangement, when the temperature difference between the plurality of points of the battery detected by the temperature detecting means becomes larger than the first predetermined value, the temperature control means reverses the direction in which the cooling medium travels in the battery. By doing
The variation in the temperature of the refrigerant is suppressed, and as a result, the variation in the temperature generated in the battery during the quick charging is suppressed, and the variation in the capacity is suppressed.

A battery charging device according to a third aspect of the present invention relates to the battery charging device according to the first aspect, wherein cooling means for cooling the battery with a refrigerant (for example, the cooling device in FIG. 3 in the embodiment), A calorific value calculating unit (for example, a calorific value calculating unit 45 in FIG. 3 in the embodiment) for calculating a calorific value, and a cooling amount calculating unit (for example, a cooling amount calculating unit in FIG. 3 in the embodiment) for calculating a cooling amount of the cooling unit. 46), and the temperature control means (for example, the temperature control unit 47 in FIG. 3 in the embodiment) controls the charging current to the battery according to the heat generation amount and the cooling amount. .

When the temperature difference between the plurality of points of the battery detected by the temperature detecting means becomes larger than the first predetermined value, the temperature control means causes the heat value of the battery calculated by the heat value calculating means to be calculated. And controlling the charging current to the battery according to the cooling amount calculated by the cooling means and the cooling amount calculated by the cooling amount calculating means, thereby suppressing the temperature rise of the battery, thereby suppressing the variation in the temperature of the refrigerant. In this case, the temperature variation generated in the battery is suppressed, and the capacity variation is suppressed.

According to a fourth aspect of the present invention, there is provided a battery charger, comprising: a battery; charging means for charging the battery;
A charging control unit that controls a charging operation of the battery by the charging unit; and a cooling unit that cools the battery with a refrigerant, and reverses a traveling direction of the refrigerant in the battery by the cooling unit every predetermined time. It is characterized by having temperature control means for causing the temperature to be controlled.

Thus, the temperature control means reverses the direction in which the refrigerant travels in the battery every time the predetermined time elapses, thereby suppressing variations in the temperature of the refrigerant. The variation in temperature that occurs during the process is suppressed, and the variation in capacity is suppressed.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A battery charging device according to a first embodiment of the present invention will be described below with reference to FIGS.

The battery charger of this embodiment is used for an electric vehicle, and as shown in FIG.
MH or other rechargeable battery 11 and an external power source such as a commercial power source and a specified charging rate (charging rate (C): 1 (C) is a current value at which the battery can be fully charged in one hour; A charger (charging means) 1 for charging the battery 11 at 2 (C) is a current value capable of fully charging the battery in 30 minutes, and 0.5 (C) is a current value capable of fully charging the battery in 2 hours.
An ECU (charge control means) 13 for designating a charging rate of the battery 11 by the charger 12 to control the charging operation thereof and for controlling the entire vehicle;
(Cooling means) that cools water with a coolant (coolant)
14.

Here, the battery 11 is composed of a plurality of modules, specifically, 24 cells each having 10 cells (not shown) as one unit. M24 is a set of two, and a total of 12 sets are arranged.

The cooling device 14 includes a battery 11
A refrigerant flow path 16 that absorbs heat from the battery 11 to lower the temperature by flowing the refrigerant into the refrigerant flow path, and a pump 17 that allows the refrigerant to flow through the refrigerant flow path 16 and rotates the refrigerant in the forward and reverse directions. And a radiator 18 that releases heat from the refrigerant after absorbing heat from the battery 11 to lower the temperature of the refrigerant.

The refrigerant flow path 16 is divided into twelve branch flow paths R1 to R12 having the same number as the number of modules M1 to M24 on the pump 17 side. After passing through a pair of two corresponding to each other, they merge. Thereby, the refrigerant cooled by the radiator 18 flows through each of the branch flow paths R1 to R12 by driving the pump 17, and the module M1
After the corresponding pair of M24 to M24 is cooled, they are merged and cooled by the radiator 18.

Specifically, the branch flow path R1 passes through a set of modules M1 and M2, the branch flow path R2 passes through a set of modules M3 and M4, and the branch flow path R3 The branch flow path R4 passes through a set of modules M7 and M8, the branch flow path R5 passes through a set of modules M9 and M10, and the branch flow path R6 passes through a set of M5 and M6.
After passing through the set of modules M11 and M12, the branch flow path R7
Passes through the pair of modules M13 and M14, the branch channel R8 passes through the pair of modules M15 and M16, the branch channel R9 passes through the pair of modules M17 and M18,
Branch flow path R10 passes through a set of modules M19 and M20, branch flow path R11 passes through a set of modules M21 and M22, and branch flow path R12 passes through modules M23 and M23.
It passes through 24 sets.

The modules M1, M3, M5, M
7, M9, M11, M13, M15, M17, M19,
M21 and M23 are all arranged on the same side (referred to as upstream side) in the normal flow direction of the refrigerant flow path 16, and the modules M2, M4, M6, M8, M10, M12, M
14, M16, M18, M20, M22, and M24 are all disposed on the same side (referred to as a downstream side) opposite to the above in the normal flow direction of the refrigerant flow path 16. The respective shapes of the branch flow paths R1 to R12 are set such that the flow rates of the refrigerant passing therethrough are equal.

The battery charging device of this embodiment has a battery temperature detecting section (temperature detecting means) for detecting the temperature of at least two of the modules M1 to M24.
21 and 22 are provided. Here, the module M24 of the module M23 in the flow direction of the branch flow path R12.
, A battery temperature detecting section 21 is provided at an end opposite to the module M24, and a battery temperature detecting section 22 is provided at an end opposite to the module M23 of the module M24.

Here, in addition to these two ends, a battery temperature detector may be provided at an intermediate position between them, but the battery temperature detector detects the maximum value of the temperature difference between the modules M23 and M24. Since the temperature difference in the modules M23 and M24 at the upstream and downstream ends where the temperature difference of the refrigerant is the largest also becomes the maximum value, it is preferable to provide them at both ends. In addition, since the refrigerant flows evenly in the branch flow paths R1 to R12, the temperature distribution of each of the branch flow paths R1 to R12 is substantially equal, and the temperature distribution of each set of the modules M1 to M24 is also substantially equal. The battery temperature detectors 21 and 22 may be provided in at least two of M1 to M24.

The ECU 13 determines that the temperature difference between the plurality of locations of the battery 11 detected by the battery temperature detectors 21 and 22 is a first predetermined value (an upper limit value at which the temperature difference of the battery 11 can be accepted during charging, When the temperature difference becomes larger than a second predetermined value (for example, 5 ° C.), the battery 1 does not adversely affect the battery 11 during charging.
It has a temperature control unit (temperature control means) 24 for controlling the temperature difference within a threshold value of 1 (for example, 5 ° C.). Specifically, the temperature control unit 24 of the ECU 13 determines the traveling direction of the refrigerant by the cooling device 14 in the battery 11,
By performing reverse rotation by the reverse rotation of the pump 17, control is performed so that the temperature difference falls within a second predetermined value.

That is, the ECU 13 performs quick charging at a high charging rate when the battery 12 is rapidly charged by the charger 12, and then the remaining battery charge SOC becomes 100%.
%, The battery is charged at a low charging rate similar to that of normal charging to make the battery fully charged. However, at the time of quick charging, the cooling device 14 rotates the pump 17 in the normal rotation direction to, for example, 17 to each branch flow path R of the battery 11
The refrigerant is circulated so as to pass through the radiator 18 from the upstream side to the downstream side and return to the pump 17 through the radiator 18 (circulation in the direction in which the refrigerant flows from the upstream side to the downstream side in each of the branch flow paths R1 to R12 of the battery 11). Is referred to as forward circulation below)
The refrigerant cooled by the radiator 18 flows from the upstream side to the downstream side in each of the branch flow paths R1 to R12 of the refrigerant flow path 16. For example, in the modules M23 and M24, the refrigerant flows from the module M23 side to the module M24 side. Coolant flows.

Note that the ECU 13 starts operating immediately after starting charging.
The temperature difference ΔT (absolute value) of each temperature detected by each of the battery temperature detectors 21 and 22 is monitored. At this time, since each of the modules M1 to M24 generates heat substantially uniformly, the temperature of the refrigerant that absorbs heat from each of the modules M1 to M24 gradually increases along the flow direction.
Cooling efficiency will decrease along the direction of flow.

When the temperature difference ΔT detected by the battery temperature detectors 21 and 22 becomes larger than a first predetermined value, for example, 5 ° C., each branch of the refrigerant flow path 16 is determined from the direction of the refrigerant flow at this time. In each set of modules M1 to M24 arranged along the flow paths R1 to R12, the temperature of the module on the downstream side is higher than that of the module on the upstream side.
M23 of module M24 detected by
The temperature at the end opposite to the battery temperature detector 21
M24 of module M23 detected by
Can be determined to be higher than the temperature at the opposite end by more than 5 ° C. For this reason, the ECU 13
By rotating the pump 17 in the reverse direction, the pump 17 passes through the radiator 18 and the branch flow paths R1 to R1 of the battery 11.
2 circulates in the reverse direction from the downstream side to the upstream side and returns to the pump 17 (the circulation in the direction in which the refrigerant flows from the downstream side to the upstream side in each of the branch flow paths R1 to R12 of the battery 11 is the reverse direction). Circulation).

That is, each branch flow path R1 of the refrigerant flow path 16
The refrigerant cooled by the radiator 18 flows from R2 to R12 from the high temperature downstream to the low temperature upstream. For example, the refrigerant flows from the module M24 to the module M23 in the modules M23 and M24. This allows the heat absorption of the refrigerant to
Although the temperature of each set of the modules M1 to M24 decreases, the downstream side having a higher temperature in the above-described forward circulation absorbs more heat than the upstream side having a lower temperature. As a result, the module M of the module M24 detected by the battery temperature detection unit 22
The module M23 of the module M23 in which the temperature at the end opposite to the module 23 is detected by the battery temperature detecting section 21
With respect to the temperature at the end opposite to 24, the temperature difference falls within 5 ° C.

In this state, if the charging is continued, the pump 17 is returned from the pump 17 through the radiator 18 to each of the branch flow paths R1 to R12 of the battery 11 in the reverse direction from the downstream side to the upstream side and returns to the pump 17. The refrigerant is circulated in the reverse direction, and the radiator 1 is provided in each of the branch flow paths R1 to R12 of the refrigerant flow path 16.
The refrigerant cooled in 8 flows from the downstream side to the upstream side. For example, in the modules M23 and M24, the refrigerant flows from the module M24 side to the module M23 side. At this time, as described above, since the temperature of the refrigerant that absorbs heat from each of the modules M1 to M24 gradually increases in the flow direction, each of the branch flow paths R1 to R1 of the refrigerant flow path 16
In each set of modules M1 to M24 arranged along R12, the upstream one in the forward circulation has a lower cooling efficiency with the refrigerant than the downstream one in the forward circulation, and the temperature becomes higher. The temperature of the end of the module M23 detected by the detection unit 21 on the side opposite to the module M24 is higher than the temperature of the end of the module M24 detected by the battery temperature detection unit 22 on the side opposite to the module M23. Come.

Then, it is determined whether or not the temperature difference ΔT detected by the battery temperature detectors 21 and 22 is larger than a first predetermined value, for example, 5 ° C.
The ECU 13 rotates the pump 17 in the normal rotation direction, and circulates the refrigerant in the normal direction so that the refrigerant flows from the radiator 18 through the pump 17, passes the battery 11 from the upstream side to the downstream side, and returns to the radiator 18.

That is, each branch flow path R1 of the refrigerant flow path 16
The coolant cooled by the radiator 18 flows from R2 to R12 from the high-temperature upstream to the low-temperature downstream. For example, the refrigerant flows from the module M23 to the module M24 in the modules M23 and M24. This allows the heat absorption of the refrigerant to
Although the temperature of each set of the modules M1 to M24 decreases, the higher-temperature upstream device absorbs more heat than the lower-temperature downstream device. The temperature of the end of the module M23 detected by the temperature detection unit 21 on the opposite side to the module M24 decreases with respect to the temperature of the end of the module M24 detected by the battery temperature detection unit 22 on the opposite side to the module M23. , The temperature difference is within 5 ° C.

As described above, the ECU 13 sequentially switches the normal rotation and the reverse rotation of the pump 17 so that the ECU 13 detects the battery 11 detected by the battery temperature detection units 21 and 22.
When the temperature difference ΔT at a plurality of locations becomes larger than the first predetermined value, the temperature difference ΔT is controlled so as to be within the second predetermined value.

As described above, according to the battery charger of the first embodiment, the battery temperature detectors 21 and 22
Temperature differences ΔT at a plurality of locations of the battery 11 detected by
Is larger than the first predetermined value, the temperature control unit 24 of the ECU 13 controls the temperature difference ΔT to be within the second predetermined value. For example, as shown in FIG. Even if the battery 11 is charged by rapid charging until the battery voltage becomes 0 to 100%, the variation in the temperature generated in the battery 11, that is, the temperature difference ΔT is suppressed to, for example, 5 ° C., and the variation in the capacity is suppressed.

Accordingly, it is possible to prevent the life of the battery 11 from being shortened.

In addition, the temperature difference at a plurality of locations of the battery 11 detected by the battery temperature detecting sections 21 and 22 is the first.
Is larger than the predetermined value, the temperature control unit 24
By reversing the direction in which the refrigerant travels in the battery 11 by the cooling device 14, the variation in the temperature of the refrigerant is suppressed as described above, and the variation in the temperature generated in the battery 11 during rapid charging is suppressed, and the variation in the capacity is reduced. Will be suppressed.

Accordingly, it is possible to prevent the life of the battery 11 from being shortened without requiring complicated control.

In the first embodiment described above, the direction of travel of the refrigerant of the cooling device 14 in the battery 11 is reversed by reversing the pump 17, but as shown in FIG. , The refrigerant may be switched between the normal circulation and the reverse circulation in the battery 11 by switching the refrigerant flow path.

That is, a connection point 26 on the pump 17 side of the refrigerant flow path 16 on the upstream side of the battery 11 and a connection point 27 on the radiator 18 side of the refrigerant flow path 16 on the downstream side of the battery 11 are connected. 28, and a connection point 29 between the connection point 27 and the radiator 18 in the refrigerant flow path 16, which is on the upstream side of the battery 11 in the refrigerant flow path 16 and on the most opposite side to the pump 17. The connection point 30 is connected with the connection channel 31. The on-off valve 33 is connected to the connection point 29 side of the connection flow path 31.
The connection point 26 is provided with a three-way switching valve 34 and the connection point 27 is provided with a three-way switching valve 35.

Then, when the on-off valve 33 is closed and the two three-way switching valves 34 and 35 are switched so as to close the connection flow path 28, the radiator 18 passes through the pump 17 and the battery 11.
The refrigerant is circulated in the forward direction so that the refrigerant passes from the upstream side to the downstream side and returns to the radiator 18.

On the other hand, the on-off valve 33 is opened, and the two-way switching valve 3 is opened.
4 and 35, the connection flow path 28 is opened, the three-way switching valve 34 closes the refrigerant flow path 16 on the battery 11 side, and the three-way switching valve 35 is connected to the refrigerant flow path 16 on the opposite side to the battery 11. When switched to be closed, the refrigerant passes from the radiator 18 through the pump 17, further through the connection channel 28, and passes the battery 11 from the downstream side in the forward circulation to the upstream side in the forward circulation, and
It will be circulated in the reverse direction to return to radiator 18 through 1.

Even with this configuration, the same effects as described above can be obtained.

Further, the forward circulation and the backward circulation may be performed each time a predetermined time elapses in which a temperature difference ΔT is expected to occur. That is, E
The temperature control unit 24 of the CU 13 reverses the traveling direction of the refrigerant by the cooling device 14 in the battery 11 every predetermined time.

A battery charging device according to a second embodiment of the present invention will be described below with reference to FIGS. 3 to 6, focusing on differences from the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

The battery charger of this embodiment is also used for an electric vehicle, and has a battery 11 and a charger 12 similar to those of the first embodiment, as shown in FIG. Further, the cooling device 14 of the second embodiment includes a pump 17
This is the same as the first embodiment except that the forward and reverse rotations are not performed. Furthermore, in the second embodiment, a battery voltage detector 40 that detects the voltage of the battery 11 and a battery current detector 41 that detects the current of the battery 11 are provided.

In the second embodiment, as in the first embodiment, battery temperature detectors 21 and 22 for detecting temperatures of at least two of the modules M1 to M24 are provided. Also in this case, the battery temperature detecting section 21 is provided at the end of the module M23 in the flow direction of the branch flow path R12 opposite to the module M24, and the battery temperature detecting section 22 is provided at the end of the module M24 opposite to the module M23. Are provided respectively.

In the second embodiment, the module M
Refrigerant temperature detectors 42 and 43 are provided for detecting the temperatures at a plurality of locations for one of the branch flow paths R1 to R12 corresponding to at least two locations among the locations 1 to M24.
Here, the refrigerant temperature detector 42 is located at the end of the branch flow path R12 closest to the end of the module M23 opposite to the module M24, and is closest to the end of the module M24 opposite to the module M23. Branch flow path R
Twelve end positions are provided with the refrigerant temperature detectors 43, respectively.

Further, in the second embodiment, an ECU (charge control means) 44 for designating a charging rate of the battery 11 by the charger 12 and controlling the charging operation thereof and controlling the entire vehicle is provided by the ECU 44. A calorific value calculating section (calorific value calculating means) 45 for calculating a calorific value; a cooling amount calculating section (cooling amount calculating means) 46 for calculating a cooling amount of the cooling device 14;
When the temperature difference at a plurality of locations of the battery 11 detected by the battery temperature detection units 21 and 22 becomes equal to or more than a first predetermined value, the heat generation amount and the heat generation amount are controlled so as to be within a second predetermined value. A temperature control unit (temperature control means) 47 for controlling a charging current to the battery 11 according to the cooling amount;

Next, the control contents of the battery charger of the second embodiment will be described with reference to the flowchart of FIG. Note that the processing shown in the flowchart of FIG. 4 is repeatedly performed at fixed time intervals (for example, 1 sec).

The ECU 44 determines whether or not the flag = 1 (step S1). If the flag is not 1, the battery 12 is rapidly charged by the charger 12 at a high charging rate of, for example, 1.3 (C). Is performed (step S2). At this time, the cooling device 14 allows the refrigerant to flow at a predetermined flow rate. For example, from the pump 17 to the battery 1
1 is circulated from the upstream side to the downstream side through the radiator 18 and returns to the pump 17.
In each of the branch flow paths R1 to R12, the refrigerant cooled by the radiator 18 flows from the upstream to the downstream. For example, in the modules M23 and M24, the refrigerant flows from the module M23 to the module M24. At this time, since each of the modules M1 to M24 generates heat almost uniformly,
The temperature of the refrigerant that absorbs heat from 1 to M24 gradually increases along the direction of flow, and the cooling efficiency decreases along the direction of flow. That is, module M
The opposite side to the 23 module M24 is the low temperature side,
The opposite side of the module M24 to the module M23 is the high temperature side.

Then, immediately after the start of charging, the ECU 44 determines that the temperature difference ΔT (absolute value) of each temperature detected by each of the battery temperature detecting sections 21 and 22 is equal to a first predetermined value (during charging, the battery 11 It is determined whether the temperature difference exceeds an acceptable upper limit (for example, 5 ° C.) (step S).
3) If the temperature difference exceeds 5 ° C., the temperature control unit 47 determines that the temperature difference ΔT is equal to the second predetermined value (the battery 1
The charging current Ix to the battery 11 is controlled so as to be within the threshold value of the temperature difference of the battery 11 that does not adversely affect the battery 1 (eg, 5 ° C.) (step S4).

That is, the ECU 44 calculates the calorific value Qheat of the battery 11 in the calorific value calculation unit 45, and in the cooling amount calculation unit 46, the cooling amount Qcool1 on the low temperature side and the cooling amount Qcool2 on the high temperature side of the cooling device 14. Is calculated.

Here, Qheat is Q (Joule heat)
And Q (heat of reaction), where Q (joule heat) = I × ΔV = I ² × R, and Q (heat of reaction) = I ×
r, the calorific value calculation unit 45 determines that Qheat = I ×
Calculate (I × R + r). Here, ΔV is a voltage rise,
I is the battery 11 detected by the battery current detection unit 41
, R is a resistance value, and r is a heat generation coefficient, which is a value unique to the battery.

Further, the cooling amount calculating section 46 is provided with the battery 11
Amount Qcool which is the cooling performance on the low temperature side (upstream side)
1 is the detected value Tba of the low-temperature battery temperature detecting section 21.
From tt1, the detection value Water1 detected by the low temperature side refrigerant temperature detection unit 42, and the heat transfer coefficient β1,
ol1 = β1 × (Tbat1-Twater1).

Further, the cooling amount calculating section 46 controls the battery 1
Cooling amount Qcoo, which is the cooling performance on the high temperature side (downstream side) of No. 1
l2 is the detected value Tb of the battery temperature detector 22 on the high temperature side.
From att2, the detection value Water2 detected by the high-temperature-side refrigerant temperature detection unit 43, and the heat transmission coefficient β2,
cool2 = β2 × (Tbat2−Twater2)

Here, the heat transfer coefficients β1 and β2 are determined by the temperature difference between the battery 11 and the refrigerant and the amount of heat radiation (the amount of heat transferred from the heat generated by the battery 11 to the cooling water and predetermined from the battery characteristics). This is a coefficient determined in advance, and increases as the temperature difference between the battery 11 and the refrigerant increases.
Here, the heat transfer coefficients β1 and β2 are obtained from a table of the refrigerant amount C as shown in FIG. That is, the heat passage coefficients β1 and β2 change depending on the refrigerant amount C.

Then, since Qheat = Qcool1, I ² × R + r × I = β1 × (Tbatt1-
Water1), and Tbatt1 = ((I ² × R + r × I) + β1 × Twa
ter1) ÷ β1.

Further, since Qheat = Qcool2, I ² × R + r × I = β2 × (Tbatt2-T
water2), and Tbatt2 = ((I ² × R + r × I) + β2 × Twa
ter2) ÷ β2.

As a result, | Tbatt1-Tbatt2 | = ΔT = (I ² × R + r × I) × (1 / C1-1 / C2) + (Twater1-Twater2)

Then, the charging current I at which ΔT becomes a predetermined value, for example, 5 ° C., is obtained from the above equation and is set as the charging current Ix, and the current value of the battery 11 is controlled to this value. Then, the temperature difference Δ
T decreases toward 5 ° C.

In step S3, each battery temperature detector 2
If the temperature difference ΔT between the temperatures detected in the steps 1 and 22 does not exceed a first predetermined value, for example, 5 ° C., and
4, the ECU 44 determines that the voltage V of the battery 11 detected by the battery voltage detection unit 40 is equal to or lower than a predetermined voltage reference value V0 from the temperature Tbatt of the battery 11 detected by the battery temperature detection units 21 and 22. Is greater than or equal to a value obtained by adding a value obtained by multiplying the temperature correction coefficient α that is a battery-specific value, that is, whether V ≧ V0 + α × Tbatt is satisfied (step S5).

In this step S5, V ≧ V0 + α
If it is not × Tbatt, this control cycle is ended. In the above, the remaining battery capacity SO
When increasing C, every time the change control of the charging current Ix in step S4 is performed, as a result, the charging rate (C) corresponding to the charging current Ix decreases as shown in FIG. Control is performed such that the charging rate (C) decreases in multiple stages as the charging progresses.

In step S5, V ≧ V0 + α × T
If it is batt, the ECU 44 sets the flag = 1 (step S6).

If the flag is set to 1 in step S1, the ECU 44 sets the battery temperature detecting unit 21,
The temperature rise rate dT / dt of the battery 11 is calculated based on the temperature Tbatt of the battery 11 detected at 22 (step S7), and the temperature rise rate dT / dt is set to a predetermined value (for example, 1.5 (Step S8). And the temperature rise rate d
If T / dt is not equal to or greater than the predetermined value, the battery 11 is charged by the charger 12 at a charge rate of, for example, 0.2 (C) for full charge lower than that in step S2 for normal charge (step S9).

On the other hand, if the temperature rise rate dT / dt is equal to or more than the predetermined value in step S8, the charging by the charger 12 is terminated (step S10).

As described above, according to the battery charger of the second embodiment, similarly to the first embodiment, the temperature difference between a plurality of locations of the battery 11 detected by the battery temperature detectors 21 and 22 is determined. Temperature control unit 47 of the ECU 44 so that the temperature difference becomes equal to or less than a predetermined value.
, The variation in the temperature generated in the battery 11 during the rapid charging is suppressed, and the variation in the capacity is suppressed.

Therefore, it is possible to prevent the life of the battery 11 from being shortened.

Further, when the temperature difference between a plurality of points of the battery 11 detected by the battery temperature detecting sections 21 and 22 becomes equal to or more than a predetermined value, the temperature control section 47 calculates the battery value calculated by the calorific value calculating section 45. The charging current Ix to the battery 11 is controlled in accordance with the heat generation amount of the battery 11 and the cooling amount of the cooling device 14 calculated by the cooling amount calculation unit 46.
This suppresses the temperature difference from increasing, and as a result, the temperature variation that occurs in the battery 11 when performing quick charging is suppressed, and the capacity variation is suppressed.

Therefore, the battery 1
1 can be prevented from being shortened.

In the first and second embodiments described above, the case where the pump 17 is used to use the refrigerant as the cooling liquid has been described as an example. However, the refrigerant may be used as the cooling gas. A fan is used instead of the pump 17.

[0071]

As described in detail above, claim 1 of the present invention
According to the battery charger described above, when the temperature difference at a plurality of locations of the battery detected by the temperature detecting means is larger than the first predetermined value, the temperature is set so that the temperature difference becomes within the second predetermined value. Since the control is performed by the control means, it is possible to suppress the variation in the temperature generated in the battery when performing the rapid charging, and the variation in the capacity.

Accordingly, it is possible to prevent the life of the battery from being shortened.

According to the battery charging device of the second aspect of the present invention, when the temperature difference between the plurality of points of the battery detected by the temperature detecting means becomes larger than the first predetermined value, the temperature controlling means: By reversing the direction in which the refrigerant travels in the battery by the cooling means, fluctuations in the temperature of the refrigerant are suppressed, and as a result, fluctuations in the temperature occurring in the battery during rapid charging are suppressed, and fluctuations in the capacity are suppressed.

Accordingly, it is possible to prevent the life of the battery from being shortened without requiring complicated control or the like.

According to the battery charging device of the third aspect of the present invention, when the temperature difference between a plurality of points of the battery detected by the temperature detecting means becomes larger than the first predetermined value, the temperature controlling means: By controlling the charging current to the battery in accordance with the calorific value of the battery calculated by the calorific value calculating means and the cooling amount of the cooling means calculated by the cooling amount calculating means, and suppressing the temperature rise of the battery, the refrigerant Of the temperature of the battery, and as a result, the temperature variation that occurs in the battery during rapid charging is suppressed, and the variation in the capacity is suppressed.

Therefore, it is possible to prevent the battery life from being shortened by changing the control contents.

According to the battery charger of the fourth aspect of the present invention, the temperature control means reverses the traveling direction of the refrigerant in the battery by the cooling means every time the predetermined time elapses, thereby reducing the variation in the temperature of the refrigerant. And as a result,
It is possible to suppress the variation in the temperature generated in the battery when performing the rapid charging, and the variation in the capacity.

Therefore, it is possible to prevent the life of the battery from being shortened without requiring complicated control.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a part of a battery charging device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a modified example of the battery charging device according to the first embodiment of the present invention, in which some parts are shown as blocks;

FIG. 3 is a block diagram showing a configuration of a part of a battery charging device according to a second embodiment of the present invention.

FIG. 4 is a flowchart showing control contents of a battery charging device according to a second embodiment of the present invention.

FIG. 5 is a table of a heat transfer coefficient β with respect to a refrigerant amount C for obtaining a heat transfer coefficient β of the battery charging device according to the second embodiment of the present invention.

FIG. 6 is a characteristic diagram showing changes in a charging rate and a battery temperature with respect to a remaining battery charge SOC at the time of charging of a battery charging device according to a second embodiment of the present invention.

FIG. 7 is a block diagram showing a part of a battery charging device.

FIG. 8 is a characteristic diagram showing a temperature change in the modules M23 and M24 with respect to the remaining battery charge SOC at the time of quick charging of the battery charging device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Battery 12 Charger (charging means) 13 ECU (charge control means) 14 Cooling device (cooling means) 21, 22 Battery temperature detection part (temperature detection means) 24, 47 Temperature control part (temperature control means) 45 Heat generation amount calculation Section (heat generation amount calculation means) 46 cooling amount calculation section (cooling amount calculation means)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 10/50 H01M 10/50 H02J 7/10 H02J 7/10 HL (72) Inventor Ken Sakurai Saitama 1-4-1, Chuo, Wako-shi, Honda R & D Co., Ltd. (72) Inventor Kazuhiko Yagi 1-4-1, Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. 5G003 BA02 CA02 CB01 FA06 5H030 AA01 AS08 BB01 FF22 FF43 5H031 AA02 AA03 CC09 KK03

Claims (4)

[Claims] 1. A battery, charging means for charging the battery, charging control means for controlling a charging operation of the battery by the charging means, and temperature detecting means for detecting temperatures at a plurality of locations of the battery. The charge control means, when a temperature difference between a plurality of locations of the battery detected by the temperature detection means becomes larger than a first predetermined value,
A battery charger comprising: a temperature controller that controls the temperature difference to be within a second predetermined value. 2. The battery charging device according to claim 1, further comprising cooling means for cooling the battery with a refrigerant, wherein the temperature control means reverses a traveling direction of the refrigerant in the battery by the cooling means. . A cooling unit for cooling the battery with a refrigerant; a calorific value calculating unit for calculating a calorific value of the battery; a cooling amount calculating unit for calculating a cooling amount of the cooling unit; The battery charging device according to claim 1, wherein the means controls a charging current to the battery according to the heat generation amount and the cooling amount. 4. A battery comprising: a battery; charging means for charging the battery; charging control means for controlling a charging operation of the battery by the charging means; and cooling means for cooling the battery with a refrigerant; A battery charging device comprising: a temperature control unit that reverses a traveling direction of a refrigerant by the cooling unit in the battery every time the cooling unit elapses.