Patent Publication Number: US-2016221463-A1

Title: Charger, charging system, and charging method

Description:
TECHNICAL FIELD 
     The present invention relates to a technology of carrying out charging of a secondary battery. 
     BACKGROUND ART 
     In recent years, a number of techniques have been proposed relating to EV chargers that perform charging of secondary batteries mounted in EVs (Electric Vehicles). 
     For example, Patent Document 1 discloses a technology in which a charging termination condition is set as a condition in which the charging current that is supplied to an EV becomes a predetermined low current value and this charging state continues for a predetermined minimum continuous time interval, and charging is terminated upon the realization of this charging termination condition. 
     LITERATURE OF THE PRIOR ART 
     Patent Documents 
     
         
         Patent Document 1: Japanese Unexamined Patent Application Publication No. 2012-235653 
       
    
     SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
     The time interval during which an EV charger charges secondary batteries equipped in EVs tends to become over-extended. As a result, in order for the users of a large number of EVs to use an EV charger, a use limitation must be placed on the users of the EVs. 
     However, in the technology described in Patent Document 1, there is no information within the charger for identifying EVs (secondary batteries that are equipped in EVs) that have used the charger, and the problem therefore arises that the same user will repeatedly use the charger. 
     It is accordingly an object of the present invention to provide a technology that can solve the problem described hereinabove and prevent the repeated use of a charger by the same secondary battery. 
     Means for Solving the Problem 
     The charger of the present invention is provided with: 
     a power supply unit that carries out charging of a secondary battery;
 
an acquisition unit that acquires individual identification information that identifies the secondary battery; and
 
a comparison unit that compares the individual identification information acquired when starting charging of said secondary battery with individual identification information that was acquired when terminating past charging;
 
wherein the power supply unit terminates charging of the secondary battery based on the comparison results.
 
     The charging system of the present invention includes: 
     a charger; and
 
a server;
 
wherein the charger is provided with:
 
a power supply unit that carries out charging of the secondary battery;
 
the server is provided with:
 
an acquisition unit that acquires individual identification information that identifies the secondary battery; and
 
a comparison unit that compares individual identification information that was acquired when starting charging of the secondary battery with individual identification information that was acquired when terminating past charging; and
 
the power supply unit terminates charging of the secondary battery based on the comparison results.
 
     The charging method of the present invention includes steps of: 
     comparing individual identification information that was acquired when starting charging of a secondary battery and that identifies the secondary battery with individual identification information that was acquired when terminating past charging; and terminating charging of the secondary battery based on the comparison results. 
     Effect of the Invention 
     According to the present invention, the effect is obtained that the repeated use of a charger by the same secondary battery can be prevented. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing the configuration of the charging system of the first and third exemplary embodiments of the present invention. 
         FIG. 2  is a flow chart for describing the operation of the charger of the first exemplary embodiment of the present invention. 
         FIG. 3  is a block diagram showing the configuration of the charging system of the second exemplary embodiment of the present invention. 
         FIG. 4  is a flow chart for describing the operation of the charger of the second exemplary embodiment of the present invention. 
         FIG. 5  is a flow chart for describing the operation of the charger of the third exemplary embodiment of the present invention. 
         FIG. 6  is a block diagram showing the configuration of the charging system of the fourth and sixth exemplary embodiments of the present invention. 
         FIG. 7  is a flow chart for describing the operation of the charger of the fourth exemplary embodiment of the present invention. 
         FIG. 8  is a block diagram showing the configuration of the charging system of the fifth exemplary embodiment of the present invention. 
         FIG. 9  is a flow chart for describing the operation of the charger of the fifth exemplary embodiment of the present invention. 
         FIG. 10  is a flow chart for describing the operation of the charger of the sixth exemplary embodiment of the present invention. 
         FIG. 11  is a block diagram showing an outline of the configuration of the charger of the present invention. 
         FIG. 12  is a block diagram showing an outline of the configuration of the charging system of the present invention. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Exemplary embodiments of the present invention are next described with reference to the accompanying drawings. 
     (1) First Exemplary Embodiment 
       FIG. 1  shows the configuration of the charging system of the present exemplary embodiment. 
     As shown in  FIG. 1 , the charging system of the present exemplary embodiment includes: EV  10  and EV charger  20 . 
     In the present exemplary embodiment, the charging method of EV  10  is assumed to be a charging method of the CHAdeMO standard. The CHAdeMO standard is a specification in which the control of the start and termination of charging is from the EV  10  side to EV charger  20 . 
     EV charger  20  includes: display unit  21 , power supply unit  22 , storage unit  23 , acquisition unit  24 , and comparison unit  25 . 
     Display unit  21  displays various screens. 
     Power supply unit  22  carries out charging of the secondary battery of EV  10 . 
     Storage unit  23  stores various types of information. 
     Acquisition unit  24  acquires charging information of the secondary battery of EV  10 . The charging information is one example of the individual identification information that identifies the secondary battery of EV  10 , and is information that indicates the charge rate of the secondary battery of EV  10  at a point in time and a time stamp value. 
     Comparison unit  25  compares the charge rate that is indicated by the charging information at the start time of the current charging cycle with the charge rate that is indicated by charging information at the termination time of the previous charging cycle. 
     Power supply unit  22  terminates charging of the secondary battery of EV  10  based on the comparison results of comparison unit  25 . 
     Although EV charger  20  is also provided with a settlement unit that, when EV charger  20  is operated and charges usage fees, settles the usage fees of EV charger  20 , this settlement unit is omitted from the figures. 
     In addition, EV  10  is driven by electric power that is charged to the secondary battery by EV charger  20 , but this drive system is also omitted from the figures. 
     The operation of EV charger  20  of the present exemplary embodiment is next described. 
       FIG. 2  shows a flow chart for describing the operation of EV charger  20  of the present exemplary embodiment. 
     When carrying out charging of EV  10  of the CHAdeMO standard, the user first connects the charging connector of EV charger  20  to EV  10 , following which EV charger  20  carries out an insulation test of the charging cable between the main unit of EV charger  20  and the charging connector and then carries out charging of EV  10  in accordance with an instruction from EV  10 . In  FIG. 2 , the first step (Step A 1  in  FIG. 2 ) is assumed to be a step carried out after completion of the insulation test (the same holds true in the following  FIGS. 4, 5, 7, 9, and 10 ). 
     As shown in  FIG. 2 , upon receiving an instruction from EV  10  to start charging (“Yes” in Step A 1 ), power supply unit  22  starts the charging of EV  10  (Step A 2 ). 
     In addition, acquisition unit  24  acquires charging information of the start time of this charging cycle from EV  10  (Step A 3 ). In the CHAdeMO standard, the specifications stipulate that EV  10  both instruct the start and the termination of charging and transmit charging information. 
     At this time, as will be described hereinbelow, the charging information that was acquired from EV  10  at the time of termination of the previous charging cycle is saved in storage unit  23 . 
     At this point, comparison unit  25  compares the charging rate indicated by the charging information at the start time of this instance of charging with the charging rate indicated by the charging information at the termination time of the previous charging cycle that was saved in storage unit  23  (Step A 4 ) and judges whether the two charging rates match (Step A 5 ). At this time, if the difference between the two charging rates is within a predetermined range, comparison unit  25  judges that the two charging rates match. 
     If comparison unit  25  judges in Step A 5  that the charging rates match (“Yes” in Step A 5 ), power supply unit  22  judges that the same EV  10  is repeatedly using EV charger  20  and forcibly terminates charging of EV  10  (Step A 6 ). 
     In addition, display unit  21  displays a warning screen (Step A 7 ). This warning screen is a screen that displays a message such as “Due to the possibility of repeated use, charging is forcibly terminated.” 
     In addition, acquisition unit  24  acquires charging information of the termination time of this charging cycle from EV  10 , the acquired charging information is saved in storage unit  23  (Step A 8 ), following which the process returns to Step A 1  and the succeeding processes are repeated. 
     On the other hand, if comparison unit  25  judges in Step A 5  that the charging rates do not match (“No” in Step A 5 ), a standby state subsequently takes effect until the arrival of an instruction from EV  10  to terminate charging. Upon receiving an instruction to terminate charging from EV  10  (“Yes” in Step A 9 ), power supply unit  22  terminates charging to EV  10  (Step A 10 ). 
     In addition, acquisition unit  24  acquires charging information of the termination time of this charging cycle from EV  10 , the acquired charging information is saved in storage unit  23  (Step A 11 ), following which the process returns to Step A 1 , and the succeeding processes are repeated. 
     In Steps A 8  and A 11 , the charging information that precedes the termination of this charging cycle may be deleted or may be saved as is. 
     In the present exemplary embodiment as described hereinabove, EV charger  20  compares the charging rate of the starting time of this charging cycle with the charging rate of the termination time of the previous charging cycle, and when the difference between the two charging rates is within a predetermined range, judges that the two charging rates match and forcibly terminates charging to EV  10 . 
     In other words, when the charging rate of the starting time of this charging cycle matches the charging rate of the termination time of the previous charging cycle, EV charger  20  judges that, because there is a strong possibility that the same EV  10  that terminated the previous charging cycle is now attempting to again start charging, the same EV  10  is repeatedly using EV charger  20  and therefore EV charger  20  forcibly terminates charging of EV  10 . 
     Accordingly, the effect is obtained that the repeated use of EV charger  20  by the same EV  10  can be prevented. 
     In addition, in the present exemplary embodiment, the charging rate of the start time of the current charging cycle is judged to match the charging rate of the termination time of the previous charging cycle, the two charging rates are judged to match, and the charging to EV  10  forcibly terminated not only when the two charging rates completely match, but also when the two charging rates are within a predetermined range. 
     Accordingly, the effect is obtained of enabling prevention of a form of repeated use in which the same EV  10  having a secondary battery whose previous charging cycle was terminated, travels around the area in which EV charger  20  is installed to reduce the charging rate and then again attempts to start charging. 
     In the present exemplary embodiment, EV charger  20  is of a configuration that always compares the charging rate of the start time of the current charging cycle with the charging rate of the termination time of a previous charging cycle. 
     However, when a long time interval (for example, 30 minutes to one hour) has passed from the termination time of a previous charging cycle until the charging start time, it should be considered that there is a strong possibility that another EV  10  has started charging. 
     In response, EV charger  20  may carry out the comparison process of Step A 4  only when the previous charging cycle terminated within a predetermined time range (for example, 30 minutes to one hour) before the charging start time, and in other cases, may omit the comparison process of Step A 4  and advance to the process of Step A 9 . 
     However, until the stage is reached in which electricity is actually flowing, it is difficult to judge whether the electrical connection between the secondary battery of EV  10  and the EV charger  20  side will actually allow charging. As a result, when the settlement of usage fees is carried out before the start of charging, there is concern that a refund of payment will occur. 
     However, the occurrence of refunding usage fees can be prevented by using a system in which the settlement unit (not shown) settles usage fees after it has been confirmed that charging from power supply unit  22  of EV charger  20  to EV  10  has started. 
     The above-described system forcibly halts the charging to EV  10  from power supply unit  22  of EV charger  20  when settlement of usage fees has not been carried out after the passage of a fixed time interval from the confirmation of the start of charging. As a result, the occurrence of nonpayment of usage fees can also be prevented. 
     However, even when settlement of usage fees is not carried out, charging of the secondary battery of EV  10  can be carried out during the interval from confirming the start of charging until the passage of the fixed time interval. The amount that can be charged from confirming the start of charging until the passage of the fixed time is not great compared to an entire charging amount, but repeated charging during the above-described fixed time interval for which usage fees are not settled can increase the charging amount. 
     In other words, there is concern regarding the potential illicit use of EV charger  20  in which charging is carried out repeatedly from the confirmation of a charging start until the fixed time interval without settling the usage fees of EV charger  20 . 
     When the charging rate of the start time of the current charging cycle matches the charging rate of the termination time of the previous charging cycle, EV charger  20  in the present exemplary embodiment determines that there is a high possibility that the same EV  10  having a secondary battery whose previous charging cycle was terminated is now attempting to have its secondary battery charged again. As a result, EV charger  20  is able to judge that the same EV  10  is repeatedly using EV charger  20  and then will forcibly terminate the charging to EV  10 . 
     As described hereinabove, the application of the present invention enables the identification of EV  10  (user) that repeats charging from the confirmation of the start of charging until the passage of the fixed time interval without settling the usage fees of EV charger  20  and thus that is illicity using EV charger  20 . In other words, the illicit act of the user of EV  10  of repeatedly having his vehicle&#39;s battery charged for the fixed time interval without settling usage fees can be prevented. 
     (2) Second Exemplary Embodiment 
     In the first exemplary embodiment, EV charger  20  immediately judged that the same EV  10  was repeatedly using EV charger  20  when the charging rate of the start time of the current charging cycle matched the charging rate of the termination time of a previous charging cycle. 
     However, the possibility exists that the charging rates of different EVs  10  may match by coincidence, and in such cases, the use of EV charger  20  by a different EV  10  may be judged as repeated use. 
     In response to this possibility, EV charger  20  in the present exemplary embodiment judges that the same EV  10  is repeatedly using EV charger  20  when the matching of the charging rates continues for a predetermined number of times (for example, 2-3 times). 
       FIG. 3  shows the configuration of the charging system of the present exemplary embodiment. 
     As shown in  FIG. 3 , the charging system of the present exemplary embodiment differs from the configuration of the first exemplary embodiment of  FIG. 1  in that comparison unit  25  is provided with counter  251  that is the first counter. 
     The operation of EV charger  20  of the present exemplary embodiment is next described. 
       FIG. 4  shows a flow chart for describing the operation of EV charger  20  of the present exemplary embodiment. 
     As shown in  FIG. 4 , the processes of Steps B 1 -B 4  that are similar to Steps A 1 -A 4  of the first exemplary embodiment of  FIG. 2  are first carried out. 
     Next, comparison unit  25  judges whether the charging rate indicated by the charging information of the termination time of a previous charging cycle matches with the charging rate indicated by the charging information of the start time of the current charging cycle (Step B 5 ). If the difference between the two charging rates is within a predetermined range at this time, comparison unit  25  judges that the two charging rates match, as in Step A 5  of the first exemplary embodiment. 
     Upon judging in Step B 5  that the charging rates match (“Yes” in Step B 5 ), comparison unit  25  increments the count value of counter  251  by “1” (Step B 6 ) and then judges whether the count value has reached a predetermined value (for example, 2 or 3) (Step B 7 ). 
     In Step B 7 , if comparison unit  25  judges that the count value has reached the predetermined value (“Yes” in Step B 7 ), power supply unit  22  judges that the same EV  10  is repeatedly using EV charger  20 . The processes of Steps B 8 -B 10  that are similar to Steps A 6 -A 8  of the first exemplary embodiment are then carried out. Alternatively, if comparison unit  25  judges in Step B 7  that the count value has not yet reached the predetermined value (“No” in Step B 7 ), the procedure advances to the process of Step B 12 . 
     On the other hand, if comparison unit  25  judges in Step B 5  that the charging rates do not match (“No” in Step B 5 ), the count value of counter  251  is reset and returns to “0” (Step B 11 ) and the procedure advances to the process of Step B 12 . Subsequently, the processes of Steps B 12 -B 14  that are similar to Steps A 9 -A 11  of the first exemplary embodiment are carried out. 
     In the present exemplary embodiment as described hereinabove, EV charger  20  compares the charging rate of the start time of the current charging cycle with the charging rate of the termination time of a previous charging cycle, increments the count value of counter  251  when the two charging rates match, resets the count value when the two charging rates do not match, and forcibly terminates the charging to EV  10  when the count value reaches a predetermined value. 
     In other words, EV charger  20  judges that the same EV  10  is repeatedly using EV charger  20  when matching of charging rates continues for a predetermined number of times and then forcibly terminates the charging to EV  10 . 
     Accordingly, the effect is obtained of enabling prevention of an incorrect judgment that, due to the coincidental matching of the charging rates of different EVs  10 , the use of EV charger  20  by a different EV  10  is judged as repeated use. 
     The other effects are the same as for the first exemplary embodiment. 
     (3) Third Exemplary Embodiment 
     In the first exemplary embodiment, EV charger  20  judged that the same EV  10  is repeatedly using EV charger  20  if the charging rate of the start time of the current charging cycle matches the charging rate of the termination time of a previous charging cycle. 
     However, when the same user successively carries out charging of a plurality of EVs  10 , detecting that the same user is repeatedly using EV charger  20  in a plurality of EVs  10  is not possible by merely comparing the charging rate of the start time of the current charging cycle with the charging rate of the termination time of a previous charging cycle. 
     In response, EV charger  20  in the present exemplary embodiment compares the charging rate of the start time of the current charging cycle with each of the charging rates of the termination times of a predetermined number (for example 2-3) of the most recent charging cycles, and, if any of the charging rates match, judges that the same user is repeatedly using EV charger  20  in a plurality of EVs  10 . 
     The configuration itself in the present exemplary embodiment is similar to that of the first exemplary embodiment of  FIG. 1 . 
     The operation of EV charger  20  of the present exemplary embodiment is next described. 
       FIG. 5  is a flow chart for describing the operation of EV charger  20  of the present exemplary embodiment. 
     As shown in  FIG. 5 , the processes of Steps C 1 -C 3  that are similar to Steps A 1 -A 3  of  FIG. 2  of the first exemplary embodiment are first carried out. 
     At this time, in contrast to the first exemplary embodiment, of the charging cycles that have been terminated in this EV charger  20  before the start time of the current charging cycle, charging information of the termination times of a predetermined number (for example, 2-3) of the most recent charging cycles are saved in storage unit  23 . 
     Here, comparison unit  25  compares the charging rate that is indicated by charging information of the start time of the current charging cycle with each of the charging rates indicated by the charging information of the termination times of a predetermined number (for example 2-3) of the most recent charging cycles that are stored in storage unit  23  (Step C 4 ) and judges whether any of the charging rates match (Step C 5 ). At this time, it is assumed that, similar to Step A 5  of the first exemplary embodiment, comparison unit  25  judges that the two charging rates match if the difference between the two charging rates is within a predetermined range. 
     If comparison unit  25  judges in Step C 5  that any of the charging rates match (“Yes” in Step C 5 ), power supply unit  22  judges that the same user is repeatedly using EV charger  20  in a plurality of EVs  10 . Subsequently, the processes of Steps C 6 -C 8  that are similar to Steps A 6 -A 8  of the first exemplary embodiment are carried out. 
     On the other hand, if comparison unit  25  judges that none of the charging rates match (“No” in Step C 5 ), the processes of Steps C 9 -C 11  that are similar to Steps A 9 -A 11  of the first exemplary embodiment are carried out. 
     In Steps C 8  and C 11 , the charging information that precedes the termination times of a predetermined number of the most recent charging cycles including the termination time of the current charging cycle may be deleted or may be saved as is. 
     In the present exemplary embodiment as described hereinabove, EV charger  20  compares the charging rate of the start time of the current charging cycle with each of the charging rates of the termination times of a predetermined number of the most recent charging cycles and forcibly terminates charging to EV  10  if any of the charging rates match. 
     In other words, if the charging rate of the start time of the current charging cycle matches any of the charging rates of the termination times of a predetermined number of the most recent charging cycles, EV charger  20  judges that the same user is repeatedly using EV charger  20  in a plurality of EVs  10  and forcibly terminates charging to EV  10 . 
     Accordingly, the effect is obtained of enabling detection that the same user is repeatedly using EV charger  20  in a plurality of EVs  10 . 
     The other effects are similar to the effects of the first exemplary embodiment. 
     (4) Fourth Exemplary Embodiment 
     The present exemplary embodiment is equivalent to the application of EV charger  20  of the first exemplary embodiment to a charging system in which a plurality of EV chargers  20  are installed within a predetermined area. 
       FIG. 6  shows the configuration of the charging system of the present exemplary embodiment. 
     As shown in  FIG. 6 , the charging system of the present exemplary embodiment differs from the configuration of the first exemplary embodiment of  FIG. 1  in that a plurality of EV chargers  20  are installed in a predetermined area and the plurality of EV chargers  20  are configured to allow communication with each other. 
     The operation of the EV chargers  20  of the present exemplary embodiment is next described. 
       FIG. 7  shows a flow chart for describing the operation of the EV chargers  20  of the present exemplary embodiment. In  FIG. 7 , in the interest of simplifying the explanation, the explanation assumes that only one EV charger  20  other than a particular EV charger  20  is installed within a predetermined area (in other words, only two EV chargers  20  are installed within the predetermined area) (the same holds true for the following  FIGS. 9 and 10 ). 
     As shown in  FIG. 7 , upon receiving an instruction from EV  10  to start charging (“Yes” in Step D 1 ), power supply unit  22  starts charging EV  10  (Step D 2 ). 
     In addition, acquisition unit  24  acquires the charging information of the start time of this charging cycle from EV  10  (Step D 3 ). 
     At this time, as will be described hereinbelow, both charging information that was acquired from EV  10  at the termination time of the previous charging cycle of this EV charger  20  and charging information that was acquired from the other EV charger  20  at the termination time of the most recent charging cycle that was terminated in the other EV charger  20  before the start time of the current charging cycle are saved in storage unit  23   
     Here, comparison unit  25  compares the charging rate indicated by the charging information of the start time of the current charging cycle with the charging rate indicated by the charging information of the termination time of the previous charging cycle in its own EV charger  20  that is saved in storage unit  23  (Step D 4 ), and judges whether the two charging rates match (Step D 5 ). If the difference between the two charging rates is within a predetermined range at this time, comparison unit  25  judges that the two charging rates match. 
     In Step D 5 , if comparison unit  25  judges that the charging rates do not match (“No” in Step D 5 ), comparison unit  25  compares the charging rate indicated by the charging information of the start time of the current charging cycle with the charging rate indicated by the charging information of the termination time of the most recent charging cycle of the other EV charger  20  that was saved in storage unit  23  (Step D 6 ) and judges whether the two charging rates match (Step D 7 ). As described hereinabove, if the difference between the two charging rates is within a predetermined range at this time, comparison unit  25  judges that the two charging rates match. 
     If comparison unit  25  judges in either of Step D 5  or D 7  that the charging rates match (“Yes” in Step D 5  or “Yes” in Step D 7 ), power supply unit  22  determines that the same EV  10  is repeatedly using the plurality of EV chargers  20  and forcibly terminates the charging to EV  10  (Step D 8 ). 
     In addition, display unit  21  displays a warning screen (Step D 9 ). This warning screen is, for example, a screen that displays the message “Due to the possibility of repeated use, charging is forcibly terminated.” 
     Further, acquisition unit  24  acquires the charging information of the termination time of the current charging cycle from EV  10  and saves the acquired charging information in storage unit  23  (Step D 10 ). 
     In addition, acquisition unit  24  transmits to the other EV charger  20  the charging information of the termination time of the current charging cycle together with the identifier of its own EV charger  20  (Step D 11 ). This charging information is saved in storage unit  23  of the other EV charger  20  in association with the identifier of EV charger  20 . 
     The procedure subsequently returns to the process of Step D 1  and the succeeding processes are repeated. 
     On the other hand, if comparison unit  25  judges in Step D 7  that the charging rates do not match (“No” in Step D 7 ), a standby state subsequently takes effect until the arrival of an instruction from EV  10  to terminate charging. Upon receiving an instruction from EV  10  to terminate charging (“Yes” in Step D 12 ), power supply unit  22  terminates charging to EV  10  (Step D 13 ). 
     In addition, acquisition unit  24  acquires charging information of the termination time of the current charging cycle from EV  10  and saves the acquired charging information in storage unit  23  (Step D 14 ). 
     Acquisition unit  24  further transmits to the other EV charger  20  the charging information of the termination time of the current charging cycle together with the identifier of its own EV charger  20  (Step D 15 ). This charging information is saved in storage unit  23  of the other EV charger  20  in association with the identifier of EV charger  20 . 
     The procedure then returns to the process of Step D 1  and the succeeding processes are repeated. 
     In Steps D 10  and D 14 , charging information that precedes the termination time of the current charging cycle of this EV charger  20  may be deleted or may be saved as is. 
     Further, charging information that precedes the termination time of the most recent charging cycle of the other EV charger  20  may be deleted or may be saved as is. 
     In  FIG. 7 , the explanation assumes that only one other EV charger  20  other than this EV charger  20  is installed, but in some cases, two or more other EV chargers  20  may also be installed. In such cases, the processes of Steps D 6  and D 7  are executed for each of the other EV chargers  20 , and if the charging rates match for any of the other EV chargers  20  in Step D 7 , the procedure should proceed to Step D 8  and otherwise should proceed to Step D 12 . 
     In the present exemplary embodiment as described hereinabove, each of the plurality of EV chargers  20  that have been installed within a predetermined area shares the charging information, and as a result, the effect is obtained that, even when the same EV  10  repeatedly uses the plurality of EV chargers  20  that are installed within the predetermined area, this repeated use can be detected. 
     The other effects are similar to the effects of the first exemplary embodiment. 
     In the present exemplary embodiment, EV charger  20  is of a configuration that always compares the charging rate of the start time of the current charging cycle with the charging rate of the termination time of the previous charging cycle of its own EV charger  20  and the charging rates of the termination times of the most recent charging cycles of other EV chargers  20 . 
     However, when at the charging start time a long time interval (for example, 30 minutes to one hour) has elapsed from the previous charging termination time, the possibility that another EV  10  has started charging is considered to be high. 
     In response, EV charger  20  may carry out the comparison process of Step D 4  only when the previous charging cycle of its own EV charger  20  terminated within a predetermined time range (for example, 30 minutes to one hour) before the charging start time, and otherwise may omit the comparison process of Step D 4  and advance to the process of Step D 6 . 
     Alternatively, EV charger  20  may carry out the comparison process of Step D 6  only when the most recent charging of another EV charger  20  was terminated within a predetermined time range (for example, 30 minutes to one hour) before the charging start time, and otherwise, may omit the comparison process of Step D 6  and proceed to the process of Step D 12 . 
     (5) Fifth Exemplary Embodiment 
     The present exemplary embodiment is equivalent to the application of EV charger  20  of the second exemplary embodiment to a charging system in which a plurality of EV chargers  20  are installed within a predetermined area. 
       FIG. 8  shows the configuration of the charging system of the present exemplary embodiment. 
     As shown in  FIG. 8 , the charging system of the present exemplary embodiment differs from the configuration of the fourth exemplary embodiment of  FIG. 6  in that counter  251  that is the first counter and counter  252  that is the second counter are provided. 
     The operation of EV chargers  20  of the present exemplary embodiment is next described. 
       FIG. 9  is a flow chart for describing the operation of EV chargers  20  of the present exemplary embodiment. 
     As shown in  FIG. 9 , the processes of Steps E 1 -E 4  that are similar to Steps D 1 -D 4  of the fourth exemplary embodiment of  FIG. 7  are first carried out. 
     Comparison unit  25  next judges whether the charging rate indicated by the charging information of the termination time of the previous charging cycle of its own EV charger  20  matches with charging rate indicated by the charging information of the start time of the current charging cycle (Step E 5 ). As in Step D 5  of the fourth exemplary embodiment, if the difference between the two charging rates is within a predetermined range at this time, comparison unit  25  judges that the two charging rates match. 
     If comparison unit  25  judges in Step E 5  that the charging rates do not match (“No” in Step E 5 ), the count value of counter  251  is reset and thus returned to “0” (Step E 8 ) and the procedure advances to Step E 9 . 
     On the other hand, if comparison unit  25  judges in Step E 5  that the charging rates match (“Yes” in Step E 5 ), the count value of counter  251  is incremented by “1” (Step E 6 ), and comparison unit  25  judges whether the count value has reached a predetermined value (for example, 2 or 3) (Step E 7 ). 
     If comparison unit  25  judges in Step E 7  that the count value has not reached the predetermined value (“No” in Step E 7 ), comparison unit  25  compares the charging rate indicated by the charging information of the start time of the current charging cycle with the charging rate indicated by the charging information of the termination time of the most recent charging cycle of the other EV charger  20  that was saved in storage unit  23  (Step E 6 ) and judges whether the two charging rates match (Step E 10 ). As described above, if the difference between the two charging rates is within a predetermined range, comparison unit  25  determines that the two charging rates match. 
     If comparison unit  25  judges in Step E 10  that the charging rates do not match (“No” in Step E 10 ), comparison unit  25  resets the count value of counter  252 , returning the count value to “0” (Step E 17 ) and the proceeds to the process of Step E 18 . 
     On the other hand, if comparison unit  25  judges in Step E 10  that the charging rates match (“Yes” in Step E 10 ), comparison unit  25  increments the count value of counter  252  by “1” (Step E 11 ) and judges whether the count value has reached a predetermined value (for example, 2 or 3) (Step E 12 ). 
     If comparison unit  25  judges in either Step E 7  or Step E 12  that the count value has reached the predetermined value (“Yes” in Step E 7  or “Yes” in Step E 12 ), power supply unit  22  determines that the same EV  10  is repeatedly using the plurality of EV chargers  20 . The processes of Steps E 13 -E 16  that are similar to the Steps D 8 -D 11  of the fourth exemplary embodiment are subsequently carried out. If comparison unit  25  judges in Step E 12  that the count value has not reached the predetermined value (“No” in Step E 12 ), the procedure advances to the process of Step E 18 . The processes of Steps E 18 -E 21  that are similar to Steps D 12 -D 15  of the fourth exemplary embodiment are subsequently carried out. 
     Although  FIG. 9  was described on the assumption that only one EV charger  20  other than its own EV charger  20  is installed, there are also cases in which two or more other EV chargers  20  are installed. In such cases, the processes of Steps E 9 -E 12  and E 17  are executed for each of the other EV chargers  20 , and when any of the charging rates of the other EV chargers  20  match in Step E 12 , the process should advance to Step E 13  and otherwise should advance to Step E 18 . 
     In the present exemplary embodiment as described hereinabove, because each of the plurality of EV chargers  20  that are installed in a predetermined area shares the charging information, the effect is obtained that even when the same EV  10  repeatedly uses the plurality of EV chargers  20  that are installed in the predetermined area, this repeated use can be detected 
     The other effects are similar to those of the second exemplary embodiment. 
     (6) Sixth Exemplary Embodiment 
     The present exemplary embodiment is equivalent to the application of EV charger  20  of the third exemplary embodiment to a charging system in which a plurality of EV chargers  20  are installed within a predetermined area. 
     The configuration itself of the present exemplary embodiment is similar to that of the fourth exemplary embodiment of  FIG. 6 . 
     The operation of the EV chargers  20  of the present exemplary embodiment is next described. 
       FIG. 10  shows a flow chart for describing the operation of the EV chargers  20  of the present exemplary embodiment. 
     As shown in  FIG. 10 , the processes of Steps F 1 -F 3  that are similar to Steps D 1 -D 3  of the fourth exemplary embodiment of  FIG. 7  are first carried out. 
     At this time, in contrast with the fourth exemplary embodiment, the charging information of the termination times of a predetermined number (for example, 2 or 3) of the most recent charging cycles among charging cycles that were terminated by this EV charger  20  before the start time of the current charging cycle is stored in storage unit  23  together with the charging information of the termination times of a predetermined number (for example, 2 or 3) of the most recent charging cycles among charging cycles that were terminated by the other EV charger  20  before the start time of the current charging cycle. 
     Comparison unit  25  compares the charging rate indicated by the charging information of the start time of the current charging cycle with each of the charging rates indicated by the charging information of the termination times of a predetermined number (for example, 2-3) of the most recent charging cycles of its own EV charger  20  that were saved in storage unit  23  (Step F 4 ) and determines whether any of the charging rates match (Step F 5 ). As in Step D 5  of the fourth exemplary embodiment, if the difference between two charging rates is within a predetermined range at this time, comparison unit  25  judges that the two charging rates match. 
     If comparison unit  25  judges in Step F 5  that none of the charging rates match (“No” in Step F 5 ), comparison unit  25  compares the charging rate indicated by the charging information of the start time of the current charging cycle with each of the charging rates that are indicated by the charging information of the termination times of a predetermined number (for example, 2-3) of the most recent charging cycles of the other EV charger  20  that were saved in storage unit  23  (Step F 6 ) and determines whether any of the charging rates match (Step F 7 ). As described hereinabove, if the difference between two charging rates is within a predetermined range at this time, comparison unit  25  judges that the two charging rates match. 
     If comparison unit  25  judges in Step F 5  or F 7  that any of the charging rates match (“Yes” in Step F 5  or “Yes” in Step F 7 ), power supply unit  22  determines that the same user is repeatedly using a plurality of EV chargers  20  in a plurality of EVs  10 . Subsequently, the processes of Steps F 8 -F 11  that are similar to Steps D 8 -D 11  of the fourth exemplary embodiments are carried out. 
     On the other hand, if comparison unit  25  judges in Step F 7  that none of the charging rates match (“No” in Step F 7 ), the processes of Steps F 12 -F 15  similar to Steps D 12 -D 15  of the fourth exemplary embodiment are subsequently carried out. 
     In Steps F 10  and F 14 , charging information that precedes the termination times of a predetermined number of the most recent charging cycles that includes the termination time of the current charging cycle may be deleted or saved as is. 
     In addition, charging information that precedes the termination times of a predetermined number of the most recent charging cycles of the other EV charger  20  may be deleted or stored as is. 
     Although this description assumes that only one other EV charger  20  in addition to this EV charger  20  is installed in  FIG. 10 , in some cases, two or more other EV chargers  20  are installed. In such cases, the processes of Steps F 6  and F 7  may be executed for each of the other EV chargers  20 , the process advancing to Step F 8  if the charging rates of any of the other EV chargers  20  match in Step F 7  and otherwise advancing to Step F 12 . 
     Because each of the plurality of EV chargers  20  installed within a predetermined area shares charging information in the present exemplary embodiment as described hereinabove, the effect is obtained that repeated use can be detected even in a case in which the same user repeatedly uses a plurality of EV chargers  20  that are installed within the predetermined area in a plurality of EVs  10 . 
     The other effects are similar to the effects of the third exemplary embodiment. 
     Although the present invention has been described with reference to exemplary embodiments, the present invention is not limited to the above-described exemplary embodiments. The configuration and details of the present invention are open to various modifications within the scope of the present invention that will be clear to one of ordinary skill in the art. 
     In the first to sixth exemplary embodiments, example were presented in which charging information that is transmitted from EVs  10  by way of the charging cable was used as the individual identification information of the secondary batteries of EVs  10 , but the present invention is not limited to this form. For example, the individual identification information of the secondary batteries of EVs  10  may be, of the information transmitted from EVs  10  by way of the charging cable, information that enables identification of the secondary batteries of EVs  10  in addition to information of the charging rates. In addition, the method of transmitting individual identification information from EVs  10  to EV chargers  20  may be a method (for example, wireless communication) other than a method that passes by way of a charging cable. 
     Further, in the first, third, fourth, and sixth exemplary embodiments, the individual identification information of the secondary batteries of EVs  10  may be information of the license plate numbers of EVs  10 . In this case, acquisition unit  24  may employ a reading unit (not shown) that reads the license plate numbers from the license plates of EVs  10 . 
     In addition, in the first to third exemplary embodiments, the individual identification information (charging information) is stored by EV chargers  20 , but the present invention is not limited to this form, and a configuration may be adopted in which the individual identification information is stored in a server (for example a server on the Internet) provided outside EV chargers  20 . 
     Further, in the fourth to sixth exemplary embodiments, the individual identification information (charging information) was stored by each of a plurality of EV chargers  20 , but the present invention is not limited to this form, and a configuration may be adopted in which the individual identification information is saved in a specific EV charger  20  among the plurality of EV chargers  20 , or a configuration may be adopted in which the individual identification information is stored by a server (for example, a server on the Internet) that is provided outside EV chargers  20 . 
     In the fourth to sixth exemplary embodiments, a plurality of EV chargers  20  communicated directly with each other, but the present invention is not limited to this form, and may also be a form in which EV chargers  20  communicate with each other by way of a server provided outside EV chargers  20  (for example, a server on the Internet). 
     When EV chargers  20  judged that the same EV  10  was repeatedly using EV chargers  20  in the first to sixth exemplary embodiments, a warning screen was displayed on display unit  21  to notify the user, but a manager in a remote location that manages EV chargers  20  may also be notified. As the method of notifying the manager, a method such as transmitting email to the manager&#39;s terminal can be considered. 
     Still further, although the description in the first to sixth exemplary embodiments assumed that the charging method of EVs  10  was a charging method of the CHAdeMO standard, the present invention is not limited to this form and can also be applied to a charging method other than the CHAdeMO standard. In other words, in the CHAdeMO standard, EV charger  20  starts charging a secondary battery in accordance with an instruction from EV  10 , but the present invention is not limited to this form, and charging a secondary battery of EV  10  may also be started by an instruction from EV charger  20 . 
     Although the charger of the present invention was applied in EV chargers  20  that carry out charging of secondary batteries of EVs  10  in the first to sixth exemplary embodiments, the present invention is not limited to this form. The charger of the present invention can also be applied to a charger that carries out charging of the secondary battery of an electric vehicle (such as an EV, an electric motorcycle, or a power-assisted bicycle), a PC (Personal Computer), or a portable apparatus. 
     Although acquisition unit  24  and comparison unit  25  were provided inside EV chargers  20  in the first to sixth exemplary embodiments, acquisition unit  24  and comparison unit  25  may also be provided in a server (for example, a server on the Internet) that is provided outside EV chargers  20 . In this case, the server that is provided outside EV charger  20  should communicate with and control a single EV charger  20  (claims  1 - 5 ) or a plurality of EV chargers  20  (claims  6 - 9 ). 
     In the first exemplary embodiment, explanation regarding the application of the present invention to a system in which usage fees are settled after confirmation that EV charger  20  has started to charge EV  10 , and further, in which charging of EV  10  by EV charger  20  is forcibly halted when settlement of usage fees is not carried out during the passage of a fixed time interval after the confirmation of the start of charging. The other second to sixth exemplary embodiments may also allow applying this invention to this system. 
     In the fifth exemplary embodiment, an example was described in which each of a plurality of EV chargers  20  is provided with counter  252  that is the second counter, and each of the EV chargers  20  separately keep count. However, in this configuration, the possibility arises that the number of times that charging rates match cannot be appropriately counted. 
     In response, only one counter  252  may be provided in a server (for example, a server on the Internet) that is provided outside EV chargers  20 . 
     In the case of this configuration, counting the count number of each EV charger  20  by the counter provided on the server enables the identification of a specific EV  10  that repeatedly uses a plurality of EV chargers  20 . 
     Alternatively, counter  252  may be provided in each of a plurality of EV chargers  20 , and each of the plurality of EV chargers  20  shares information relating to the count numbers. 
     In order to place EVs  10  and count numbers in correspondence, count numbers that correspond to charging rates (or license plates or vehicle identification information) are shared among each of the EV chargers. 
     For example, assuming three EV chargers A, B, and C, the distance between EV chargers A and B is 500 m, the distance between EV chargers B and C is also 500 m, and the distance between EV chargers A and C is 1 km. If a range of 500 m is set as the predetermined area, checking is carried out by one item of limit information (counter information) by EV chargers A and B, and checking is carried out by one item of limit information (counter information) by EV chargers B and C. In this case, because it is possible to belong to a plurality of areas as is the case for EV charger B, the limit check must be made from a perspective removed from the number of EV chargers. In this case, EV chargers A, B, and C may share counter information. 
     Finally, an outline of the present invention is described. 
       FIG. 11  shows an outline of charger  200  of the present invention. 
     As shown in  FIG. 11 , charger  200  of the present invention has power supply unit  210 , acquisition unit  220 , and comparison unit  230 . 
     Power supply unit  210  carries out charging of secondary batteries. 
     A secondary battery for which power supply unit  210  carries out charging is a secondary battery of, for example, an electric vehicle, an electric motorcycle, a power-assisted bicycle, a PC, or a portable apparatus. 
     Acquisition unit  220  acquires individual identification information that identifies secondary batteries. 
     Comparison unit  230  compares individual identification information that was acquired at the start time of charging a secondary battery and individual identification information that was acquired at the termination time of past charging. 
     Here, the termination time of past charging refers to the time of terminating the previous charging cycle or to the termination times of a predetermined number of the most recent charging cycles. 
     Power supply unit  210  terminates charging of a secondary battery based on the comparison results of comparison unit  230 . 
     As a result, charger  200  can forcibly terminate charging of a secondary battery when it determines on the basis of the comparison results of comparison unit  230  that the same secondary battery is repeatedly using charger  200 . 
     As a result, the effect is obtained that the repeated use of charger  200  by the same secondary battery can be prevented. 
       FIG. 12  shows an outline of the charging system of the present invention. 
     As shown in  FIG. 12 , the charging system of the present invention has charger  200  and server  300 . 
     Charger  200  has power supply unit  210 . 
     Power supply unit  210  carries out charging of a secondary battery. 
     The secondary battery for which power supply unit  210  performs charging is the secondary battery of, for example, an electric vehicle, an electric motorcycle, a power-assisted bicycle, a PC, or a portable apparatus. 
     Server  300  has acquisition unit  310  and comparison unit  320 . 
     Acquisition unit  310  acquires individual identification information that identifies secondary batteries. 
     Comparison unit  320  compares individual identification information acquired at the start time of charging of a secondary battery with individual identification information acquired at the termination time of a past charging cycle. 
     Here, the termination time of a past charging cycle refers to the termination time of the previous charging cycle or the termination times of a predetermined number of the most recent charging cycles. 
     Power supply unit  210  terminates charging of a secondary battery on the basis of the comparison results of comparison unit  320 . 
     As a result, charger  200  can forcibly terminate charging of a secondary battery when it determines based on the comparison results of comparison unit  320  that the same secondary battery is repeatedly using charger  200 . 
     As a result, the effect is obtained that the repeated use of charger  200  by the same secondary battery can be prevented. 
     This application claims the benefits of priority based on Japanese Patent Application No. 2013-222122 for which application was submitted on Oct. 25, 2013 and incorporates by citation all of the disclosures of that application.