JP2003244862A - Battery charger for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To utilize an existing power facility, as it is, without performing the extension work on a power facility, even when a charger for the battery of a vehicle, the power capacity of the power facility for performing the power supply to the charger is small. <P>SOLUTION: In the charger 2, where a charge control part 20 controls the charge current to be supplied from a power supply part 12 to a battery 6 into a preset target current at least in its initial stage of the beginning of the charge, when charging the battery 6 to serve as the power source of a forklift or the like, the user inputs a command for changing the charge current via a final control element 22, thereby enabling himself to optionally set the target current at battery charge. As a result, it becomes possible to increase or decrease the power to be consumed in the charger 2 at battery charge, according to the power capacity of the power facility, thus this battery charger can properly charge the battery 6, even when there is no margin in the power capacity of the power facility by the action of other electric load connected to the power facility. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle battery charging device used for charging a battery as a power source in an electric vehicle powered by a battery.

[0002]

2. Description of the Related Art Conventionally, electric vehicles, such as industrial vehicles such as battery-powered forklifts and electric vehicles, which operate by receiving power from a battery are known. A vehicle of this type is usually equipped with a charging device for charging the battery.

The charging device is of a constant current type for charging the battery with a constant current, or the charging current is set to be high at the start of charging and low at the end of charging.
A two-stage constant current system that switches the battery by switching between stages and controls the charging current to the battery at a constant current at the start of charging, and then when the battery voltage reaches the set voltage, the charging voltage to the battery is changed. Various charging methods such as a constant current constant voltage method that charges a battery by controlling to a set voltage are known, but any charging method charging device is used to take in commercial power from the outside. A power cord is provided, and this power cord
The battery is charged by connecting to a power outlet supplied with commercial power.

[0004]

By the way, in such a battery charger for a vehicle, the charging current to the battery is several tens A to hundreds of tens A, and the power consumption during charging is large. In a facility where a possible power outlet is installed (so-called desk lamp, factory where industrial vehicles are used, etc.), another charging device is connected to the power facility of the facility, or it is installed in advance in the facility. When an electric load other than the existing charging device is operating, when the charging device was connected to the power outlet, the load capacity of the power supply equipment exceeded the allowable range and the breaker flew. .

In order to prevent such a problem, the power supply capacity of the power supply equipment to which the charging device is connected may be increased. However, in order to increase the power supply capacity, the additional work of the power supply equipment is required, resulting in a large amount of money. It will incur expense. The present invention has been made in view of these problems, and in a vehicle battery charger, even if the power supply capacity of the power supply facility that supplies power to this charger is small, an additional power supply facility is installed. The purpose is to make it possible to use existing power supply facilities without modification.

[0006]

According to another aspect of the present invention, there is provided a vehicle battery charger as set forth in claim 1, wherein the charging means receives power from an external power source and supplies a charging current to the battery. The charging control means controls the charging means so that the charging current supplied from the charging means to the battery becomes a preset target current, and the target current setting means, in accordance with an input command from the outside, controls the charging control means. Set the target current used to control the charging means.

That is, in the conventional vehicle battery charger, the target current for controlling the charging current to the battery is preset according to the capacity of the battery to be charged and the charging method, and the target is set. Since the current could not be changed, in the present invention, the target current used when the charging current control unit controls the charging current can be arbitrarily set by an input command from the outside, so that the battery It is designed so that the power consumed by the charging device during charging can be increased or decreased.

As a result, according to the vehicle battery charging apparatus of the present invention, the target current for controlling the charging means by the target current setting means is set in accordance with the power capacity of the power supply facility for supplying power to the charging equipment. You will be able to set it.
Therefore, according to the vehicle battery charger of the present invention, it is possible to charge the battery satisfactorily without blowing the breaker of the power supply facility that supplies power to the charger.

Here, the target current setting means is only required to be able to set the target current in accordance with a command input from the outside. For example, the target current setting means performs wireless or wired data communication with an electronic device operated by a user, The target current may be set according to a command signal input by data communication.

However, in this case, the target current setting means needs to have a communication function, which causes a problem that the cost of the charging device increases. Further, in charging the battery using the charging device, when the charging device is mounted on the vehicle together with the battery, the user needs to connect the charging device to an external power source, and conversely, If the device is installed separately from the vehicle while being connected to the external power supply, the user needs to connect the charging device and the battery mounted on the vehicle, and therefore When using the battery to charge the battery, the user must be near the charging device to connect the electric system, and the target current setting means can set the target current by remote control by communication. The effect obtained by configuring the above is also small.

Therefore, when actually constructing the vehicle battery charging device of the present invention, an operating portion for inputting a command for setting the target current is provided, and the target current setting means is set forth in claim 2. It is good to configure like. That is, in the vehicle battery charger according to claim 2, the target current setting means displays the currently set target current on the display means when a target current setting command is input from the operation unit,
After that, when the target current change command is input from the operation unit, the target current being displayed on the display unit is updated according to the change command, and when the target current confirmation command is input from the operation unit, the display unit is displayed. The target current being displayed is set as the target current used by the charging control unit to control the charging unit.

Therefore, if the vehicle battery charging device of the present invention is configured as described in claim 2, the user charges the battery using the charging device before connecting the electric system. Alternatively, later, the target current may be set by operating the operation unit and confirming the target current displayed on the display means. Therefore, according to the vehicle battery charging device of the second aspect, the charging device of the present invention can be manufactured at a low cost without deteriorating the usability of the user, as compared with the case where the target current setting means has a communication function. Will be realized.

On the other hand, the information displayed on the display means when the user operates the operating portion to set the target current may be only the information indicating the target current instructed by the user, but more preferably the target current. By configuring the setting means as described in claim 3, it is possible to display on the display means, when the battery is charged according to the target current in addition to the target current commanded by the user, the charging is completed. It is advisable to display information indicating the time required.

That is, in the vehicle battery charger according to the third aspect, the target current setting means predicts the time required to complete charging of the battery based on the target current displayed on the display means, Since the prediction result is displayed on the display means together with the target current, the user can confirm the change in the battery charging time caused by changing the target current on the display screen when setting the target current. The usability when setting the target current can be improved.

In this case, the prediction result displayed by the target current setting means on the display means together with the target current may be the time from the start of charging the battery to the completion of the charging. May be the time (date and time) at which the start is completed when the charging is started from the current time or a start time set separately.

Further, the display form when the target current setting means displays the target current on the display means may be any display form as long as the user can confirm the target current set / changed on the display screen. The current value of the target current may be displayed numerically on the display means, or the ratio to the preset maximum value of the target current (eg rated current) may be displayed numerically (eg percentage display). ), Or these values (current value or ratio) may be displayed as a bar in an analog manner.

On the other hand, according to the present invention, the target current used for controlling the charging means can be externally set by the charging control means, so that the electric power consumed by the charging device at the time of charging the battery can be increased or decreased. Therefore, the present invention can be applied to a constant current type charging device that constantly controls the charging current to a constant current (target current), but the present invention is not limited to such a constant current type charging device. Any charging method such as the two-stage constant current method or the constant current / constant voltage method described above may be used as long as it is a charging method that controls the current at the initial stage of charging.

That is, as described in claim 4, in the initial stage after the start of charging the battery, the charging control means performs current control for controlling the charging means so that the charging current becomes the target current. After the voltage of the battery reaches the set voltage by the current control, the charging means is controlled so that the current or the voltage supplied from the charging means to the battery reaches the preset second control target value. If so (that is, in the above-described two-stage constant current type or constant current constant voltage type), the target current setting means controls the current at the initial stage after the charging control means starts charging the battery. The target current when executing is to be set according to an input command from the outside.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 is a block diagram showing an overall configuration of a vehicle battery charger (hereinafter, simply referred to as a charger) 2 of an embodiment to which the present invention is applied.

The charging device 2 of this embodiment is mounted on a battery-powered forklift and a battery 6 for supplying power to an on-vehicle device (motor or the like) 4 serving as a drive source of the forklift.
Is used by connecting a power cord (not shown) to a power outlet in a factory where a battery-powered forklift is used.

As shown in FIG. 1, the charging device 2 of the present embodiment.
Is a power supply unit 12 that converts an AC power supply (commercial power supply) supplied from electric equipment in the factory via a power cord into a DC voltage and current suitable for charging and supplies the DC voltage and current to the battery 6.
The current detection unit 14 and the voltage detection unit 1 that detect the current and the voltage supplied from the power supply unit 12 to the battery 6, respectively.
6, a temperature sensor 18 for detecting the ambient temperature, a charge control unit 20 for charging the battery 6 by controlling the power supply unit 12 based on the detection signals from the current detection unit 14 and the voltage detection unit 16, and this charging An operation unit 22 for inputting various commands such as charging start / stop to the control unit 20
And a display unit 24 for displaying various states of the charging device 2.
With.

Here, the power supply unit 12 corresponds to the charging means of the present invention, and rectifies the AC power (commercial power) supplied from the electric equipment in the factory through the power cord with the rectifying element. Rectifier circuit 12a for generating a DC voltage
And an output circuit 1 for supplying the DC voltage generated by this rectifier circuit to the battery 6 via a semiconductor element for power control.
2b and.

On the other hand, the charge control unit 20 includes a CPU, RO
It is composed of a microcomputer including M, RAM and the like, and when a charge start command to the battery 6 is input from the operation unit 22, the power supply unit 12 is based on the detection signals from the detection units 14 and 16. The internal output circuit 12b (specifically, a power control semiconductor element) is controlled.

That is, as shown in FIG. 2, the charging control unit 20 detects the charging detected by the current detection unit 14 immediately after the charging start command of the battery 6 is input from the operation unit 22 (initial charging). The current control is performed to control the output circuit 12b so that the current becomes the preset first control current (target current) I1, and by this current control, the charging voltage (battery voltage) detected by the voltage detection unit 16 is performed. When a preset control voltage (for example, a reversal voltage at which gas starts to be generated from the battery 6: a so-called gassing voltage) is reached, the charging current detected by the current detector 14 is then set to a preset value. 2 Until the control current I2 is reduced (in the middle of charging), voltage control is performed to control the output circuit 12b so that the charging voltage detected by the voltage detection unit 16 becomes the control voltage. When the charging current is reduced to the second control current I2 by the second current control for controlling the output circuit 12b so that the charging current becomes the second control current I2 for a preset fixed time (end of charging). The charge control of the battery 6 is performed in the procedure of executing.

That is, the charging control unit 20 functions as the charging control means of the present invention, and in the present embodiment, the charging control of the battery 6 is performed by the constant current constant voltage constant current drive system. The charging control unit 20 controls the power supply unit 1 so that the vehicle-mounted device 4 does not operate when the battery 6 is charged.
When AC power is supplied to 2 (in other words, when the power cord is connected to the power outlet in the factory), an interlock which is a switch provided on the power supply path from the battery 6 to the vehicle-mounted device 4 The device 8 is controlled to the open state, the power supply from the battery 6 to the vehicle-mounted device 4 is cut off, and after the charging control is completed, the charging completion command is input from the operation unit 22 and the AC power is supplied to the power supply unit 12. Is cut off (in other words, the power cord is disconnected from the power outlet in the factory), the interlock device 8 is returned to the closed state, and the power supply from the battery 6 to the vehicle-mounted device 4 is restarted. .

Next, in the charging device 2 of the present embodiment, by operating the operating portion 22, the first control current (target current) I1 which is the control target value at the initial charging time when the power consumption becomes maximum. Can be set arbitrarily. That is,
In the present embodiment, the charging control unit 20 follows the charging current change command input from the operation unit 22, and outputs the first control current I
1 is changed and stored in a non-volatile memory (for example, EEPROM) built in the charge control unit 20 and also functions as the target current setting unit of the present invention, and the battery 6 thereafter.
At the time of charging, the latest first control current I1 stored in the non-volatile memory area is used as the target current, and the current control immediately after the start of charging (initial charging) is executed.

When the charging control unit 20 updates the first control current I1 according to the instruction from the operation unit 22, the display unit 24 changes the first control current I1 according to the instruction of the user.
Is used as the display means of the present invention that displays the charge completion time, and the temperature sensor 18 is used to predict the charge completion time.

The control processing executed by the charging control unit 20 for updating the first control current I and controlling the charging will be described below with reference to the flowchart shown in FIG. This process is repeatedly executed by the charging control unit 20 when the power cord of the charging device 2 is connected to the power outlet in the factory. When this process is activated, the charging device 2 First, in S110 (S represents a step), the display unit 24 displays a menu screen for the user to operate the operation unit 22 to input various commands.

This menu screen is for allowing the user to select various commands including the above-mentioned charging current change command. For example, as shown in FIG. 4 (a), various command contents are listed in order. Has become. Then, when the “>” key or “<” key for menu selection provided on the operation unit 22 is pressed while the menu screen is displayed, the charging control unit 20 displays the menu screen according to the key operation. When the command content to be identified and displayed is changed by an underline or the like and the "M" key for confirming the command content is pressed, it is determined that the user has selected the command content that is currently identified and displayed.

That is, the charging control unit 20 displays the menu screen on the display unit 24 in S110, and then the operation unit 22.
Each time the key operation is performed, it is determined in S120 whether or not the operated key is the “M” key. If it is not the “M” key, the process proceeds to S110 again and the user's key is pressed. In response to the operation (pressing the ">" key or the "<" key), change the command content to be displayed on the menu screen for identification (use the ">" key to move up and the "<" key to move down). If it is the "M" key, it is determined that some command content is selected on the menu screen, and the process proceeds to S130.

Next, in S130, it is determined whether or not the instruction content selected by operating the "M" key is a charging current change instruction. If the instruction content is a charging current change instruction, the process proceeds to S150. After shifting, the charging current change screen is displayed on the display unit 24. This charging current change screen is, for example, as shown in FIG. 4B, the currently set charging current (first control current I1), the current date and time, and the currently set charging current (first control current I1). It is composed of three pieces of information such as the date and time when charging is completed when the battery 6 is charged with the control current I1), and in S150, the first control current I1 is read from the non-volatile memory area and charging on the display screen is performed. The current value is numerically displayed in the current display area, the current date and time is read from the clock built in the charge control unit 20, the read date and time is numerically displayed in the current date and time display area, and the charging current is displayed. First control current I displayed in the area
The time required to complete the charging of the battery 6 when the charge control of the battery 6 is executed by the first control current I1 and the current battery voltage detected by the voltage detection unit 16 and the temperature sensor 18 are Prediction is performed using the detected ambient temperature, and the estimated time is added to the current date and time to calculate the charging completion date and time, and the calculated charging completion date and time is displayed numerically in the completion date and time display area. In steps
Display the charging current change screen.

The battery voltage and ambient temperature are used to predict the time required for charging, because the current control period at the beginning of charging changes depending on the battery voltage at the start of charging and the ambient temperature, and This is because the control period changes depending on the ambient temperature and the current control period at the end of charging is constant.

That is, in S150, the time required for the current control at the initial stage of charging is predicted by using the first control current I1, the battery voltage and the ambient temperature, and the time required for the voltage control in the middle charging period is set in advance. Predicted by correcting the charging time when the ambient temperature is constant with the current ambient temperature,
The time required for charging the battery 6 is predicted by adding these predicted times and the current control execution time at the end of charging.

In this way, when the charging current change screen is displayed on the display unit 24, the process proceeds to S160, and the user presses the ">" key or "<" key of the operation unit 22. Determines whether or not a charging current change command has been input. When it is determined in S160 that the charging current change command is input, the process proceeds to S170, and the charging current of the display unit 24 is changed according to the “>” key or “<” key operated by the user. The charging current (first control current I1) displayed in the display area is set to a predetermined current value (for example, 10 A).
Increase / decrease by a unit (increase 10A by ">" key, decrease 10A by "<" key), and proceed to S180.

The upper limit of the charging current (first control current I1) is set to the rated current value of the battery 6, and the lower limit of the charging current (first control current I1) is the target at the time of executing current control at the end of charging. Current (second control current I2) is set to S
At 170, the charging current (first control current I1) being displayed on the display unit 24 is updated within this range.

Next, in S180, the time required to charge the battery 6 is predicted using the charging current (first control current I1) updated in S170, the current battery voltage and the ambient temperature. The charging completion date and time is calculated by adding the estimated time to the current date and time, and the charging completion date and time being displayed in the completion date and time display area is updated. The procedure for predicting the charging time of the battery 6 is the same as the procedure in S150.

Next, at S160, it is judged that the charging current change command is not inputted, or at S1.
At 80, when the charging completion date and time displayed on the display unit 24 is updated, the process proceeds to S190, and this time, the user presses the “M” key on the operation unit 22 to display the charging current. It is determined whether a confirmation command has been input.

When it is determined in S190 that the charging current confirmation command has not been input, the process proceeds to S160 again, and conversely, in S190, it is determined that the charging current determination command has been input. Then, the process proceeds to S200, and the charging current (first control current I1) currently displayed on the display unit 24 is stored in the nonvolatile memory area as the latest charging condition.
Move to 110.

Next, in S130, when it is determined that the instruction content selected by the operation of the "M" key is not the charging current change instruction, the process proceeds to S210 and "M".
It is determined whether or not the command content selected by operating the key is a charge start command. If the command content is the charging start command, the process proceeds to S220, and the latest charging condition (first control current I) stored in the non-volatile memory area is stored.
In step S230, the display unit 24 displays a charging condition screen including the charging current, the current date and time, and the charging completion date and time corresponding to the read charging condition.

The charging condition screen shown in FIG. 4 (c) is similar to the charging current change screen shown in FIG. 4 (b), except that the charging start command is immediately issued after the charging conditions are set. It shows the screen when it is input, and in reality, the display content may be different from the charging current change screen. That is, in S230, similar to the above-described processing of S150 or S180, the charging time required when the battery 6 is charged using the first control current I1 set as the charging condition is predicted, and the predicted time is charged. The date and time added to the date and time when the command is input is set as the charging completion date and time, and the current date and time is also set to the current date and time read from the clock.

Next, in S230, when the charging condition screen is displayed on the display unit 24, this time, the processing proceeds to S240, and charging control of the battery 6 is started. In addition, this control is shown in FIG.
Is executed by the above-described procedure described using. Further, at the time of executing this charge control, a current date / time updating process of sequentially updating the current date / time on the charging condition screen displayed on the display unit 24 is also executed.

Then, when the control of charging the battery 6 is started in S240, the charging of the battery 6 by the charging control is performed by determining whether or not the charging of the battery 6 is completed in the subsequent S250. After completion of the charging, when the charging is completed, the process proceeds to S260, and a message indicating that the charging is completed (charging completion screen) is displayed on the display unit 24.

Then, in S270, the user waits for the charging completion command to be input by looking at the charging completion screen and operating the operation unit 22, and when the charging completion command is input. , And the process proceeds to S110 again. Next, if it is determined in S210 that the command content selected by operating the "M" key is not the charging start command, S
Moving to 280, the control process corresponding to the command content (command different from charging current change command and charging start command) selected by the user by operating the “M” key is executed, and S1 is executed again.
Go to 10.

The control process executed in S280 is, for example, an image for the user to set the charging start date and time in accordance with the start reservation command selected by the user to perform the reserved charging of the battery 6. Is displayed on the display unit 24, and a start reservation process for receiving the charging start date and time according to the operation of the operation unit 22 by the user, or an image for setting the charging completion date and time according to the completion reservation command selected by the user is displayed. A completion reservation process, which is displayed on the unit 24 and receives the charging completion date and time in accordance with the operation of the operation unit 22 by the user, can be cited.

As described above, in the charging device 2 of the present embodiment, by operating the operating portion 22, the target current (first control current I
1) can be set to any current value. Therefore, the user can appropriately set the power consumed by the charging device 2 when the battery 6 is charged, according to the power capacity of the power supply facility that supplies power to the charging device 2.
If the charging device 2 of the present embodiment is used, the battery 6 can be satisfactorily charged without increasing the power capacity of the power supply facility.

Further, in the charging device 2 of this embodiment, the date and time when the charging of the battery 6 is completed is predicted when the charging current (first control current I1) is set or when the charging control is executed, and the display unit 24 is operated. Since it is displayed, the user can set the charging current (first control current I1) while confirming the charging completion date and time when setting the charging current (first control current I1). , It is possible to grasp the charging completion date and time at a glance. Therefore, according to the present embodiment, it is possible to provide the user with the convenient charging device 2.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment,
Various aspects can be adopted. For example, in the above-described embodiment, the charging current (first control current I1) is displayed on the display unit 24 by the numerical display of the current value. However, for example, as shown in FIG. Alternatively, the ratio of the charging current to the rated current of the battery 6 may be displayed as a bar in an analog manner.

Further, in the above embodiment, the charging device 2 of the constant current constant voltage constant current system in which the battery 6 is charged in the procedure shown in FIG. 2 has been described. However, in the present invention, the charging current is always a constant current. Even if it is a constant current type charging device that controls to (target current), or even a two-stage constant current type charging device that switches the charging current in two stages, it is applied in the same manner as in the above embodiment, The same effect can be obtained.

In the above embodiment, when the charging completion date and time is displayed on the display unit 24, the first control current I1 set by the user, the battery voltage at the start of charging, and the ambient temperature are used. However, the charging time varies depending on not only the ambient temperature and the battery voltage representing the discharge state of the battery 6 but also the secular change of the battery 6. More preferably, the charging time actually required when charging the battery 6 is measured, the prediction error of the charging time due to the secular change of the battery 6 is learned from the measured result, and the learning result is used to It is advisable to correct the charging time predicted in the procedure.

Furthermore, in the above-described embodiment, the charging completion date and time are displayed on the display unit 24 when the charging current (first control current I1) is set or when the charging control is executed, but as described above. The estimated charging time (time required to charge the battery 6) may be displayed as it is.
In this case, at the time of executing the charging control, the charging time displayed on the display unit 24 is sequentially reduced in association with the progress of charging,
It suffices to display the remaining time until the charging is completed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a charging device according to an embodiment.

FIG. 2 is a time chart explaining the charging operation of the charging device of the embodiment.

FIG. 3 is a flowchart illustrating a control process executed by a charge control unit of the charging device according to the embodiment.

FIG. 4 is an explanatory diagram showing information displayed on a display unit when a charging current is set and when charging control is executed.

FIG. 5 is an explanatory diagram illustrating a modification example of a display form of a charging current on a display unit.

[Explanation of symbols]

2 ... Charging device, 4 ... In-vehicle device, 6 ... Battery, 8 ... Interlock device, 12 ... Power supply unit, 12a ... Rectifier circuit,
12b ... Output circuit, 14 ... Current detection part, 16 ... Voltage detection part, 18 ... Temperature sensor, 20 ... Charge control part, 22 ... Operation part, 24 ... Display part.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H02J 7/02 H02J 7/02 VF term (reference) 5G003 AA01 BA01 CA02 CA14 EA01 FA06 GC05 5H030 AA01 AA08 AS08 BB01 FF22 FF42 FF43 5H115 PC06 PG04 PI16 PO01 PO07 PO10 PV07 SE06 TI01 TI05 TO12 TO13

Claims (4)

[Claims] 1. A vehicle battery charging device used for charging a battery as a power source of a vehicle, comprising a charging means for receiving a power supply from an external power source and supplying a charging current to the battery. A charging control unit that controls the charging unit so that the charging current supplied from the charging unit to the battery becomes a preset target current, and the charging control unit controls the charging unit according to an input command from the outside. And a target current setting means for setting the target current used for charging the battery charging device for a vehicle. 2. An operating unit for inputting the command for setting the target current, wherein the target current setting means is currently set when the setting command for the target current is input from the operating unit. Display the target current on the display,
After that, when the target current change command is input from the operation unit, the target current being displayed on the display unit is updated according to the change command, and the target current confirmation command is input from the operation unit. And a target current being displayed on the display means is set as a target current used by the charging control means to control the charging means.
The vehicle battery charger described. 3. The target current setting means predicts a time required to complete charging of the battery based on the target current being displayed on the display means, and outputs the prediction result together with the target current. The vehicle battery charging apparatus according to claim 2, wherein the battery is displayed on a display means. 4. The charging control means performs current control for controlling the charging means so that the charging current becomes the target current at an initial stage after the start of charging of the battery, and the current control controls the current. After the voltage of the battery reaches the set voltage, the charging unit is configured to control the charging unit so that the current or the voltage supplied from the charging unit to the battery reaches a preset second control target value, The target current setting unit sets a target current when the charge control unit executes the current control in an initial stage after starting charging of the battery according to an input command from the outside. The vehicle battery charger according to any one of claims 1 to 3.