Patent Publication Number: US-2016221455-A1

Title: Charging system of in-vehicle battery and charging method of in-vehicle battery

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a charging system of an in-vehicle battery and a charging method of an in-vehicle battery. 
     2. Description of Related Art 
     With the recent spread of electric vehicles and plug-in hybrid vehicles, infrastructure such as charging stands for charging an in-vehicle battery has been organized. Charging modes of an in-vehicle battery can currently be classified into a normal charging mode in which the in-vehicle battery is charged with AC power sources of 100 V, 200 V, and the like and a quick charging mode in which the in-vehicle battery is charged with DC high-voltage power sources of 50 kW and the like. Among these charging modes, the quick charging mode has a merit that the charging time is shorter than that in the normal charging mode, but since a large current flows in a charging cable, a plurality of measures for safety is normally employed. 
     For example, Japanese Patent Application Publication No. 2005-312224 (JP 2005-312224 A) proposes a device that calculates an amount of electricity charged during the quick charging as an accumulated value of a current and that stops the quick charging when the accumulated value is equal to or greater than a limit value, in order to suppress an excessive rise in temperature of a battery liquid, a transformer, a rectifying portion, and the like even in the quick charging. 
     In the device described in JP 2005-312224 A, the excessive rise in temperature of the battery liquid, the transformer, the rectifying portion, and the like can be suppressed, but, for example, the possibility of electric leakage accompanied with a problem in a charging cable or a connector is not considered. Accordingly, there is room for improvement in consideration of measures for electric leakage in the quick charging. 
     SUMMARY OF THE INVENTION 
     The present invention provides a charging system of an in-vehicle battery and a charging method of an in-vehicle battery that can enhance safety in charging the in-vehicle battery with an external charging device capable of performing quick charging. 
     A charging system of an in-vehicle battery according to a first aspect of the invention is configured to charge the in-vehicle battery with an external charging device capable of performing quick charging. The charging system of the in-vehicle battery according to the first aspect of the invention includes a rainfall information acquiring unit and a controller. The rainfall information acquiring unit is configured to acquire rainfall information that is information indicating whether it is raining. The controller is configured to control a charging mode of the in-vehicle battery with the external charging device. The controller is configured to inhibit performing of the quick charging or to reduce an amount of charging current in the quick charging based on the rainfall information, which indicates that it is raining, acquired by the rainfall information acquiring unit. 
     A charging method of an in-vehicle battery according to a second aspect of the invention is a charging method of charging the in-vehicle battery with an external charging device capable of performing quick charging. The charging method includes: causing a rainfall information acquiring unit to acquire rainfall information that is information indicating whether it is raining; causing a controller to control a charging mode of the in-vehicle battery with the external charging device; and inhibiting the performing of the quick charging or reducing an amount of charging current in the quick charging based on the rainfall information, which indicates that it is raining, acquired by the rainfall information acquiring unit at a time of controlling the charging mode. 
     According to the first and second aspects of the invention, the performing of the quick charging is inhibited or the amount of charging current in the quick charging is reduced under the condition that the information indicating that it is raining is acquired. When the performing of the quick charging is inhibited, it is possible to prevent electric leakage due to the wetting of a charging cable or a connector having a problem. On the other hand, when the amount of charging current is reduced, it is possible to enhance the measures for electric leakage without greatly damaging convenience for a user. Accordingly, it is possible to enhance safety in charging the in-vehicle battery. 
     In the first aspect of the invention, the controller may be configured to select he quick charging and normal charging, which is charging using an AC current, of the in-vehicle battery. The controller may be configured to select the normal charging based on the rainfall information, which indicates that it is raining, acquired by the rainfall information acquiring unit. 
     According to this configuration, the control when the information indicating that it is raining is acquired includes selecting the normal charging with an AC current. Accordingly, the charging of the in-vehicle battery is not inhibited. As a result, it is possible to enhance the measures for electric leakage without greatly damaging convenience for a user. 
     In the first aspect of the invention, the controller may be configured to acquire a state of charge of the in-vehicle battery and to predict, based on the acquired state of charge, a charging end time when the normal charging is selected. The controller may be configured to select the normal charging under a condition that the predicted charging end time is equal to or less than a desired charging end time set by a user. 
     According to this configuration, when the charging end time is equal to or less than the desired charging end time, the normal charging is selected. Accordingly, it is possible to perform minimum measures for electric leakage without greatly damaging convenience for a user. 
     In the first aspect of the invention, the controller may be configured to acquire a state of charge of the in-vehicle battery and to predict a charging end time when the normal charging is selected based on the acquired state of charge. The controller may be configured to perform the quick charging with the reduced amount of charging current under a condition that the predicted charging end time is greater than a desired charging end time set by a user. 
     According to this configuration, when the predicted charging end time is greater than the desired charging end time, the quick charging with the reduced amount of charging current is performed. Accordingly, it is possible to appropriately cause the convenience based on the quick charging and the enhancement of the measures for electric leakage to be compatible with each other. 
     In the first aspect of the invention, the rainfall information acquiring unit may be a rain sensor mounted on a vehicle and configured to detect whether it is raining based on wetting of the vehicle. According to this configuration, it is determined by the rain sensor mounted on a vehicle body for controlling of a wiper whether it is raining. Accordingly, even when the vehicle body is wet for reasons other than rain, such as a car wash, as well as rainfall or snowfall, it is possible to detect wetting of the vehicle in real time. An existing sensor may be effectively used without providing a new particular sensor as measures for electric leakage. 
     In the first aspect of the invention, the rainfall information acquiring unit may be configured to acquire weather information of an area in which the external charging device is installed. According to this configuration, it can be determined whether it is raining, as long as a device that can receive information from facilities providing weather information is provided. The rainfall information acquiring unit may be disposed in any of the vehicle and the external charging device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein: 
         FIG 1  is a block diagram schematically illustrating a configuration of a vehicle and an external charging device in a first embodiment of a charging system of an in-vehicle battery and a charging method of an in-vehicle battery according to the invention; 
         FIG. 2  is a flowchart illustrating a charging operation in the first embodiment; 
         FIG. 3  is a flowchart illustrating a charging operation in a second embodiment of a charging system of an in-vehicle battery and a charging method of an in-vehicle battery according to the invention; 
         FIG. 4  is a flowchart illustrating a charging operation in a third embodiment of a charging system of an in-vehicle battery and a charging method of an in-vehicle battery according to the invention; 
         FIG. 5  is a block diagram schematically illustrating a configuration of a vehicle and an external charging device in a fourth embodiment of a charging system of an in-vehicle battery and a charging method of an in-vehicle battery according to the invention; 
         FIG. 6  is a flowchart illustrating a charging operation in the fourth embodiment; 
         FIG. 7  is a block diagram schematically illustrating a configuration of a vehicle and an external charging device in a fifth embodiment of a charging system of an in-vehicle battery and a charging method of an in-vehicle battery according to the invention; and 
         FIG. 8  is a block diagram schematically illustrating a configuration of a vehicle and an external charging device in a modification example of a charging system of an in-vehicle battery and a charging method of an in-vehicle battery according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
     Hereinafter, a first embodiment of a charging system of an in-vehicle battery and a charging method of an in-vehicle battery will be described below In this embodiment, an electric vehicle in which an in-vehicle battery is charged with an external charging device such as a charging stand will be exemplified as a vehicle on which the in-vehicle battery is mounted. 
     As illustrated in FIG. I. a vehicle  100  includes a drive battery  11  that is a drive source of a running motor (not illustrated). The drive battery  11  is a known battery of several hundreds of volts and is constituted, for example, by a lithium ion secondary battery. 
     The drive battery  11  is connected to a charging controller  12  via a charging power supply line  24 . The charging controller  12  is a device that controls a charging mode of the drive battery  11  in cooperation with a charging controller  32  on the external charging device  30  side. Particularly, in this embodiment, cable groups  23 ,  33  connected to a vehicle-side connector  21  and a connector  31  on the external charging device  30  side include a quick-charging cable, a normal-charging cable, and a communication line used for communication between the charging controller  12  and the charging controller  32 . The quick charging and the normal charging using the dedicated cables can be switched by communication between the charging controllers  12 ,  32 . Here, the quick charging means charging with a DC current and the normal charging means charging with an AC current. 
     In this embodiment, the vehicle  100  is provided with a rain sensor  20  that detects attachment of raindrops to a front window or the like for the purpose of wiper control or the like. The rain sensor  20  outputs a detection signal (rainfall information) indicating whether it is raining to a charging-control electronic control unit (ECU)  15 . The ECU  15  outputs a control command to the charging controller  12  on the basis of the rainfall information. The ECU  15  is also a device that monitors a state of charge (SOC) of the drive battery  11  through the use of the charging controller  12 . The charging controller  12 , the rain sensor  20 , and the ECU  15  operate with a supply of power from an auxiliary battery  13  similarly mounted on the vehicle  100 . 
     A charging operation in this embodiment that is performed in cooperation with the vehicle  100  and the external charging device  30  will be described below. In the charging system, the quick charging is selected as standard charging. 
     As illustrated in  FIG. 2 , the ECU  15  acquires rainfall information under the condition that the vehicle-side connector  21  and the external connector  31  are connected to each other (step S 1 ). Subsequently, the ECU  15  determines whether it is raining on the basis of the rainfall information (step S 2 ). Here, the rainfall information from the rain sensor  20  includes a detected amount of raindrops (amount of rainfall). Accordingly, at the time of determination, the ECU  15  determines that “it is raining” when the amount of raindrops is greater than a predetermined value. Here, the case where it is determined that “it is raining” includes a case where it is snowing or raining and a case where the vehicle body is wet for reasons other than rain, such as a car wash. 
     When the ECU  15  determines that it is not raining (NO in step S 2 ), the ECU  15  commands the charging controllers  12 ,  32  to start the quick charging as the standard charging. Accordingly, the quick charging is started (step S 3 ). 
     During the quick charging, the ECU  15  acquires the rainfall information similarly to step S 2  (step S 4 ) and continues to determine whether it is raining (step S 5 ). When it is determined that the charging is completed or the stop of the charging due to disconnection of the vehicle-side connector  21  and the external connector  31  or the like is detected in the state where it is determined that it is not raining (NO in step S 5 ), the ECU  15  performs a charging terminating process of commanding, the charging controller  12  to terminate the charging (step S 7 ) and terminates a series of charging operations. 
     On the other hand, when it is determined that it is raining before the quick charging or during the quick charging (YES in step S 2  or S 5 ), the ECU  15  transmits a normal charging request to the charging controller  32  of the external charging device  30  and the charging controller  12  via the communication lines of the cable groups  23 ,  33  (step S 8 ). Accordingly, the charging controller  32  of the external charging device  30  and the charging controller  12  of the vehicle  100  start the normal charging using an AC current via the normal-charging cable (step S 9 ). Similarly to step S 6 , when it is determined that the charging is completed or the charging is stopped (YES in step S 10 ), the charging terminating process is performed (step S 7 ) and a series of charging operations is terminated. 
     As described above, the charging system of an in-vehicle battery and the charging method of an in-vehicle battery according to this embodiment can achieve the following advantages. (1) When the information indicating that it is raining is transmitted on the basis of the rainfall information acquired through the use of the rain sensor  20  by the ECU  15  of the vehicle  100 , the charging mode is switched so as to select the normal charging instead of the quick charging. Accordingly, even when it is raining, it is possible to enhance measures for electric leakage without greatly damaging convenience for a user at the time of charging. As a result, it is possible to enhance safety in the charging operation of the drive battery  11 . 
     (2) In this embodiment, it is determined whether it is raining through the use of the rain sensor  20  disposed in the vehicle body. Accordingly, even when the vehicle body is wet for reasons other than rain, such as a car wash, as well as rainfall and snowfall, it is possible to detect that “it is raining”. Since the existing rain sensor  20  provided for wiper control can be effectively used, it is not necessary to newly provide a particular sensor far measures for electric leakage. 
     Second Embodiment 
     A second embodiment of the charging system of an in-vehicle battery and a charging method of an in-vehicle battery will he described below with a focus placed on differences from the first embodiment. The basic configuration of the charging system of an in-vehicle battery according to this embodiment is equal to the system configuration of the first embodiment. Substantially the same elements as in the charging method according to the first embodiment out of the charging method of an in-vehicle battery according to this embodiment will be referenced by the same reference numerals and description thereof will not be repeated. 
     A charging operation of the charging system according to this embodiment will be described below with reference to  FIG. 3 . In this embodiment, similarly to the first embodiment, the ECU  15  acquires rainfall information (step S 1 ) and determines whether it is raining (step S 2 ). When it is determined that it is not raining (NO in step S 2 ), the ECU  15  starts the quick charging as a standard charging mode (step S 3 ) and then continues to perform the quick charging of the drive battery  11  until it is determined that the charging is completed or the charging is stopped. 
     On the other hand, when it is determined that it is raining (YES in step S 2 ), the ECU  15  predicts a charging end time Tchg in the normal charging (step S 20 ). At this time, the ECU  15  acquires the state of charge of the drive battery  11  through the use of the charging controller  12  and calculates the time until the state of charge reaches a target value from the state of charge at that time on the basis of the amount of charging current in the normal charging. For example, the target value corresponds to a full state of charge and is set in advance depending on a battery type. 
     Then, the ECU  15  acquires a desired charging end time Tdmn set by the vehicle  100  side (step S 21 ). The desired charging end time Tdmn is a time that is set in advance in a memory (not illustrated) in the vehicle  100  through the use of an input operation unit on the vehicle  100  side by a user. The ECU  15  compares the calculated charging end time Tchg with the desired charging end time Tdmn and determines whether the charging end time Tchg is equal to or less than the desired charging end time Tdmn (step S 22 ). 
     When it is determined that the charging end time Tchg is equal to or less than the desired charging end time Tdmn (YES in step S 22 ), the ECU  15  transmits a normal charging request (step S 8 ) and continues to perform the normal charging until it is determined that the charging is completed or the charging is stopped (steps S 9 , S 10 ). 
     On the other hand, even when it is determined that the charging end time Tchg is greater than the desired charging end time Tdmn (NO in step S 22 ) but it is determined that it is raining, the ECU  15  performs the quick charging as a kind of exception routine with priority given to the charging (step S 3 ). Until it is determined that the charging is completed or the charging is stopped, the quick charging of the drive battery  11  is continuously performed (steps S 3 , S 6 ). 
     As described above, the charging system and method of an in-vehicle battery according to this embodiment can achieve the following advantage addition to the advantages of (1) and (2). 
     (3) The normal charging is actively selected when the charging end time Tchg is equal to or less than the desired charging end time Tdmn, and it is thus possible to enhance the minimum measures for electric leakage without greatly damaging the convenience for a user. 
     Third Embodiment 
     A third embodiment of the charging system of an in-vehicle battery and a charging method of an in-vehicle battery will be described below with a focus placed on differences from the first embodiment and the second embodiment. The basic configuration of the charging system of an in-vehicle battery according to this embodiment is equal to the system configuration of the first embodiment. Substantially the same elements as in the charging method according to the first embodiment and the second embodiment out of the charging method of an in-vehicle battery according to this embodiment will be referenced by the same reference numerals and description thereof will not be repeated. 
     A charging operation of the charging system according to this embodiment will be described below with reference to  FIG. 4 . In this embodiment, similarly to the first embodiment, the ECU  15  acquires rainfall information (step S 1 ) and determines whether it is raining (step S 2 ). When it is determined that it is not raining (NO in step S 2 ), the ECU  15  starts the quick charging (step S 3 ) and then continues to perform the quick charging of the drive battery  11  until it is determined that the charging is completed or the charging is stopped (steps S 3 , S 6 ). 
     On the other hand, when it is determined that it is raining (YES in step S 2 ), the ECU  15  predicts the charging end time Tchg in the normal charging, similarly to the second embodiment (step S 20 ) and acquires the desired charging end time Tdmn set by the vehicle side (step S 21 ). Then, the ECU  15  compares the predicted charging end time Tchg with the desired charging end time Tdmn and determines whether the charging end time Tchg is equal to or less than. the desired charging end time Tdmn (step S 22 ). 
     When it is determined that the charging end time Tchg is equal to or less than the desired charging end time Tdmn (YES in step S 22 ), the ECU  15  transmits a normal charging request similarly to the second embodiment (step S 8 ) and continues to perform the normal charging of the drive battery  11  until it is determined that the charging is completed or the charging is stopped (steps S 9 , S 10 ). 
     On the other hand, when it is determined that the charging end time Tchg is greater than the desired charging end time Tdmn (NO in step S 22 ), the ECU  15  computes an amount of current with which the drive battery can be charged in the quick charging, that is, the charging using a DC current, with a smaller amount of charging current than that in the normal quick charging within the user&#39;s desired charging end time Tdmn (step S 30 ). At this time, for example, the ECU  15  subtracts the state of charge (%) at that time from the target value (%) of the state of charge of the drive battery  11 , converts the difference into an necessary amount of power, and converts the amount of power into an amount of current to be calculated on the basis of the amount of power and the desired charging end time Tdmn. 
     The ECU  15  determines whether the drive battery can be charged with the computed amount of current within the desired charging end time Tdmn on the basis of various conditions (step S 31 ). When it is determined in step S 31  that the drive battery can be charged, the ECU  15  sets the computed amount of current as the amount of charging current in the quick charging (step S 32 ) and then performs the quick charging (step S 3 ). That is, in this case, the quick charging with a reduced amount of current is performed. 
     As described above, the charging system and method of an in-vehicle battery according to this embodiment can achieve the following advantage in addition to the advantages of (1) and (2). 
     (4) The quick charging with a reduced amount of current is performed when the charging end time Tchg is greater than the desired charging end time Tdmn, and it is thus possible to cause the convenience based on the quick charging and the enhancement of the measures for electric leakage to be compatible with each other. 
     Fourth Embodiment 
     A fourth embodiment of a charging system of an in-vehicle battery and a charging method of an in-vehicle battery will be described below with a focus placed on differences from the first embodiment. The basic configurations of the charging system of an in-vehicle battery and the charging method of an in-vehicle battery according to this embodiment are equal to the configurations of the first embodiment illustrated in  FIG. 1 . Substantially the same elements in  FIG. 5  as in the first embodiment will be referenced by the same reference numerals and description thereof will not be repeated. 
     As illustrated in  FIG. 5 , the vehicle  100  includes a device that can receive information from facilities providing weather information. In this embodiment, the device includes a communication unit  41  that performs vehicle information and communication system (VICS: registered trademark) communications. The vehicle  100  includes a UPS receiver unit  42  that detects the position of the vehicle. The VICS information acquired by the communication unit  41  and the information of the vehicle position received from the GPS receiver unit  42 , which have been acquired, for example, just before an ignition key is turned off, are stored in a memory or can be acquired by the ECU  15  even after the ignition key is turned off. 
     The charging operation of the charging system according to this embodiment will be described below with reference to  FIG. 6 . The ECU  15  acquires the position information of the vehicle  100 , that is, the position information of a charging stand in which the external charging device  30  is placed, and the VICS information including the weather information as the rainfall information under the condition that the vehicle-side connector  21  and the external connector  31  are connected to each other. Furthermore, the ECU  15  acquires the weather information of an area including the charging location (step S 41 ). The ECU  15  determines whether it is raining on the basis of the weather of the time point included in the weather information (step S 42 ). For example, it is determined that it is raining when the weather of the area is rainy or snowy, and it is determined that it is not raining when the weather is fair or cloudy. 
     When it is determined that it is not raining (NO in step S 42 ), the ECU  15  performs the quick charging until it is determined that the charging is completed or the charging is stopped (steps S 3 , S 6 ). Here, the weather information is not checked during the quick charging, and the reason thereof is that the update cycle of the weather information is generally longer than the time required for the quick charging. 
     On the other hand, when it is determined that it is raining on the basis of the weather information (YES in step S 2 ), the ECU  15  transmits a normal charging request (step S 8 ) and continues to perform the normal charging until the charging is completed or the charging is stopped (steps S 9 , S 10 ). 
     As described above, the charging system and method of an in-vehicle battery according to this embodiment can achieve the following advantages. (5) When the information indicating that it is raining is transmitted on the basis of the weather information acquired through the use of the communication unit  41 , the charging mode is switched so as to perform the normal charging instead of the quick charging. Accordingly, even when it is raining, it is possible to enhance the measures for electric leakage without greatly damaging convenience for a user. As a result, it is possible to enhance safety in the charging operation of the drive battery  11 . 
     (6) Since the existing communication unit  41  or the GPS receiver unit  42 , which are often mounted on a vehicle as a standard in recent years, can be effectively used, it is not necessary to newly provide a particular sensor for the measures of electric leakage. 
     Fifth Embodiment 
     A fifth embodiment of a charging system of an in-vehicle battery and a charging method of an in-vehicle battery will be described below with a focus placed on differences from the first embodiment and the fourth embodiment. The basic configurations of the charging system of an in-vehicle battery and the charging method of an in-vehicle battery according to this embodiment are equal to the configurations of the first embodiment and the fourth embodiment illustrated in  FIG. 1 or 5 . Substantially the same elements in  FIG. 7  as in the first embodiment and the fourth embodiment will be referenced by the same reference numerals and description thereof will not be repeated. 
     As illustrated in  FIG. 7 , the external charging device  30  installed in a charging stand and the like includes a communication unit  51  in addition to the external connector  31 , the charging controller  32 , and the cable group  33 . The communication unit  51  is a device that receives information from facilities providing weather information and, for example, is a unit that performs the VICS communication. A vehicle  100  has a configuration in which the rain sensor  20  is removed from the vehicle  100  according to the first embodiment or the use thereof is skipped. 
     The charging operation of the charging system according to this embodiment is different from the charging operation of the fourth embodiment illustrated in  FIG. 6 , in that the acquiring of the weather information in step S 41  is performed by the communication unit  51  of the external charging device  30 . The charging operations illustrated in  FIG. 6  are sequentially performed in such a way that the weather information acquired through the use of the communication unit  51  is fed back from the charging controller  32  of the external charging device  30  to the ECU  15  via the charging controller  12  of the vehicle  100 . 
     As described above, the charging system and the charging method of an in-vehicle battery according to this embodiment can achieve the following advantages. (7) When the information indicating that it is raining is transmitted on the basis of the weather information acquired through the use of the communication unit  51 , the charging mode is switched so as to perform the normal charging instead of the quick charging by the ECU  15  to which the information has been fed back from the charging controller  32  of the external charging device  30 . Accordingly, even when it is raining, it is possible to enhance the measures for electric leakage without greatly damaging convenience for a user. As a result, it is possible to enhance safety in the charging operation of the drive battery  11 . 
     (8) Since the weather information is acquired by equipment on the side of charging stands that are absolutely smaller than the number of vehicles, it is possible to simplify vehicle-side equipment as a charging system that takes measures for electric leakage for the quick charging. 
     Other Embodiments 
     The above-mentioned embodiments may be implemented in the following aspects. As illustrated in  FIG. 8 , the rain sensor in the first to third embodiments may be connected to the external charging device  30 . The rain sensor  60  in this aspect is disposed outdoor and detects an amount of raindrops (amount of rainfall) of a detection area disposed to attach raindrops thereto at the time of raining. The detection result of the rain sensor  60  is fed back to the ECU  15  from the charging controller  32  via the charging controller  12  of the vehicle  100 , as described in the fifth embodiment Alternatively, the charging controller  32  may determine whether it is raining on the basis of the rainfall information acquired by the rain sensor  60 , may select a charging mode for the drive battery  11 , and may request the ECU  15  for the normal charging or the quick charging with a reduced amount of current. This aspect can achieve the advantages similar to the advantages of (7), (8). 
     In the first embodiment, it is determined even during the quick charging whether it is raining, but the quick charging may continue to be performed without determining whether it is raining until the charging is completed or stopped after the quick charging is determined. 
     In the third embodiment, the quick charging with a reduced amount of current is selected when the charging end time Tchg is greater than the desired charging end time Tdmn, but the quick charging with a reduced amount of current may be selected without comparing the charging end time Tchg with the desired charging end time Tdmn. That is, immediate when the ECU  15  determines that it is raining, the drive battery  11  may be charged with a DC current with a smaller amount of current than the amount of charging current in the normal quick charging. 
     In the fourth embodiment, similarly to the second, embodiment, the charging end time Tchg may be compared with the desired charging end time Tdmn when the ECU  15  determines that it is raining, and the normal charging may be selected when the charging end time Tchg is equal to or less than the desired charging end time Tdmn. Alternatively, similarly to the third embodiment, when the charging end time Tchg is greater than the desired charging end time Tdmn, the amount of current with which the drive battery can be charged within the desired charging end time Tdmn may be computed and the quick charging may be performed with the computed amount of charging current. 
     In the fifth embodiment, similarly to the second embodiment, the charging end time Tchg may be compared with the desired charging end time Tdmn when the ECU  15  to which the weather information has been fed back determines that it is raining, and the normal charging may be selected when the charging end time Tchg is equal to or less than the desired charging end time Tdmn. Alternatively, similarly to the third embodiment, when the charging end time Tchg is greater than the desired charging end time Tdmn, the amount of current with which the drive battery can be charged within the desired charging end time Tdmn may be computed and the quick charging may be performed with the computed amount of charging current. 
     In the fifth embodiment, the ECU  15  requests for the normal charging when it is determined that it is raining, but the charging controller  32  of the external charging device  30  may request the vehicle  100  for the normal charging. 
     In the above-mentioned embodiments, the external charging device  30  and the ECU  15  of the vehicle  100  transmit and receive various signals via the communication lines of the cable groups  23 ,  33 , but may transmit and receive various signals therebetween by wireless communication. 
     In the above-mentioned embodiments, the quick charging is set as a standard charging mode, the ECU  15  selects the normal charging or the quick charging, and the charging is automatically performed in the selected mode. Instead, after the normal charging is selected, availability of the normal charging or the quick charging with a reduced amount of current may be displayed on a display (not illustrated) disposed in the external charging device  30  so as to cause a user to allow the charging. The charging is performed when a user operates the display so as to allow the normal charging or the quick charging with a reduced amount of current, and the charging may be stopped when the user operates the display so as to inhibit the normal charging or the quick charging with a reduced amount of current. Alternatively, the ECU  15  or the charging controller  32  may transmit an E-mail or the like inquiring about whether the normal charging or the quick charging with a reduced amount of current should he allowed to a portable terminal having a communication function, which is carried by the user. When a notification for allowing the charging based on the user&#39;s operation is received, the charging controller  32  starts the normal charging or the quick charging with a reduced amount of current. According to this configuration, it is possible to cause a user to confirm the intention and it is thus possible to enable the charging based on the user&#39;s intention. 
     In the above-mentioned embodiments, the vehicle  100  includes the auxiliary battery  13  in addition to the drive battery  11 , but a configuration in which power is supplied to a running motor and various controllers by only the drive battery  11  or a voltage controller may be employed. 
     In the above-mentioned embodiment, the charging system of an in-vehicle battery is exemplified as a system for charging an electric vehicle, but may be used as a system for charging other types of vehicles. For example, a plug-in hybrid vehicle that runs using a running motor and an engine in parallel may be used as the charging target.