Battery charging control method and battery charging control device

Abstract

A battery charging control method comprising: Determining by a charging determiner (100) whether a charging prohibition condition has been met based on first state information of a vehicle and second state information of a first battery (600) at a charging interval of a predetermined time period (S120) when the charging determiner (100) performs a periodic charging mode based on a first ignition voltage (IG voltage) applied thereto, Performing charging by the charging determiner (100) based on a determination result based on third state information of a second battery (500) (S300 - S330) by a first control device (200) as to whether a critical charging condition has been met when the charging determiner performs an automatic charging mode based on a second IG voltage applied thereto, Calculating a voltage change of the second battery (500) selected from the third state information by the first control device (200) and setting at least one of a charging time and a charging voltage by the first control device (200) based on the calculated voltage change or setting the charging interval by the charging determiner (100) based on the calculated voltage change, Determining by the charging detector (100) based on the applied IG voltage whether execution of the automatic charging mode or the periodic charging mode is required (S110), Activating a relay (700) by a second control device (400) (S130, S320) and carrying out charging of the second battery (500) by the first control device (200) (S230, S430) when the third state information corresponds to the critical charging condition, wherein the activation of the relay (700) by the second control device (400) (S130, S320) and the carrying out of the charging of the second battery (500) by the first control device (200) (S230, S430) when the third state information corresponds to the critical charging condition comprises: Requesting, by the first control device (200), the charging detecting means (100) to allow charging if the third state information corresponds to the critical charging condition (S220, S410), and Requesting, by the charging detecting means (100), the second control means (400) to activate the relay (700) based on the charging permission request (S130, S330).

Description

BackgroundField of the invention

[0001] The present invention relates to a battery for an electric vehicle and, more particularly, to a method and apparatus for controlling the charging of an auxiliary battery of an electric vehicle (e.g., an electric motor vehicle). Description of the technology used

[0002] Electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) equipped with a charging system are provided with two batteries, namely a main battery, which is designed to supply an electric motor with drive power (or drive energy) to drive wheels, and an auxiliary battery, which is designed to supply general electrical elements (e.g. electrical consumers) with electrical power (or energy).

[0003] In other words, such an EV requires an operating voltage to start or initialize electrical elements, and a drive voltage to power an electric motor to propel the EV. The operating voltage and the drive voltage are supplied by the batteries. To supply the drive voltage, a high-voltage battery (or main battery) is generally used, which has a relatively high energy density and a relatively high output density (e.g., output power). However, electrical elements of the EV operate at numerous voltages (e.g., at different low voltage levels) and are thus configured to receive a desired voltage from a separate electrical element battery (or auxiliary battery) configured to supply a voltage suitable for the electrical elements.

[0004] However, despite the presence of the main battery to power the vehicle, the auxiliary battery may be discharged after the internal combustion engine is shut down. Once the auxiliary battery is discharged to a final discharge voltage, the auxiliary battery can no longer be used, and consequently, re-operation of the vehicle may become impossible.

[0005] Accordingly, in order to solve the problems caused by the discharge of the auxiliary battery, numerous techniques have been developed in the related art. For example, a technique in which a power supply from an auxiliary battery is automatically cut off (e.g., disconnected) when a predetermined condition is met (e.g., when a door is locked, after the engine is turned off, under the condition that the headlights are in an ON state), a power supply from an auxiliary battery is automatically cut off (e.g., disconnected) or the headlights are automatically turned off, and a technique in which a power supply from an auxiliary battery is automatically cut off (e.g., disconnected) when a predetermined time has elapsed after vehicle accessories (ACC) (e.g., vehicle accessories) are turned on have been developed.However, such related art methods have a limitation in addressing the discharge of the auxiliary battery caused by leakage current (e.g., creepage current, leakage current, dark current). Therefore, it is necessary to provide a charge control technology capable of maintaining the auxiliary battery at least in a chargeable state.

[0006] Furthermore, a battery charging control method and a related device are known from EP 2 535 218 A1, which discloses: determining by a charging determiner whether a charging prohibition condition has been met based on first state information of a vehicle and second state information of a first battery at a charging interval of a predetermined time period when the charging determiner performs a periodic charging mode based on a first ignition voltage (IG voltage) applied thereto; performing charging by the charging determiner based on a determination result based on third state information of a second battery by a first control device as to whether a critical charging condition has been met when the charging determiner performs an automatic charging mode based on a second IG voltage applied thereto;and calculating a voltage change of the second battery selected from the third state information by the first control device and setting at least one of a charging time and a charging voltage by the first control device based on the calculated voltage change or setting the charging interval by the charging determiner based on the calculated voltage change.

[0007] Further battery charging control methods and devices as well as relevant techniques are known from KR 10 2015 0 130 671 A, JP 2014 - 90 630 A, WO 2014 / 124 996 A1 and JP 2012 - 80 684 A. Explanation

[0008] It is an object of the present invention to provide an auxiliary battery charging control method and an auxiliary battery charging control device that substantially obviate one or more problems due to limitations and disadvantages of the related art. An object of the present invention is to provide an auxiliary battery charging control method and an auxiliary battery charging control device capable of controlling charging of an auxiliary battery in an automatic or periodic manner based on an ON / OFF state of an ignition voltage (IG voltage (hereinafter, "IG" shall stand for "ignition")) in consideration of the voltage drop (e.g., voltage dip) caused by a load of the electrical elements and a leakage current.

[0009] Additional advantages, objects, and features of the exemplary embodiments will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned from practice of the exemplary embodiments. The objects and other advantages of the embodiments may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

[0010] To this end, the present invention provides a battery charging control method according to claim 1. Advantageous further developments are described in the dependent claims.

[0011] Furthermore, the battery charging control method may include: the first controller completing (e.g., stopping) charging of the second battery when the third state information exceeds (e.g., exceeds) the critical charging condition. The battery charging control method may further include: the charging determiner transmitting information regarding the determined charging mode to the first controller when at least one of the first state information and the second state information does not correspond to the charging prohibition condition (e.g., at least one of the first state information and the second state information corresponds to the charging prohibition condition).

[0012] The activation of the relay by the second control device and the carrying out of the charging of the second battery by the first control device when the third state information corresponds to the critical charging condition may comprise: obtaining, by the first control device, the third state information of the second battery from a second battery sensor, and determining, by the first control device, whether the third state information corresponds to the critical charging condition (e.g., the third state information corresponds to the critical charging condition).

[0013] Completion (e.g., stopping) of charging of the second battery by the first controller when the third state information exceeds the critical charging condition may include: requesting, by the first controller, the charging determiner to complete (e.g., stop) charging; and requesting, by the charging determiner, the second controller to deactivate the relay based on the charging completion request. Completion of charging of the second battery by the first controller when the third state information exceeds the critical charging condition may include: initialization of the charging interval (e.g., restarting the charging interval (e.g., restarting by checking whether the current time corresponds to the end of the charging interval or whether the elapsed time corresponds to the duration of the charging interval)) by the charging determiner.

[0014] Furthermore, the present invention provides a battery charging control device according to claim 7. Advantageous further developments are described in the dependent claims.

[0015] The first control device can then be configured to complete (e.g., terminate) the charging of the second battery when the third state information exceeds the critical charging condition. The charging determiner can be configured to transmit information based on the determined charging mode to the first control device when at least one of the first state information and the second state information does not correspond to the charging prohibition condition (e.g., when at least one of the first state information and the second state information does not correspond to the charging prohibition condition).

[0016] The battery charging control device may further comprise: a battery sensor configured to transmit the third state information of the second battery to the first control device. In particular, the first control device may be configured to determine whether the third state information corresponds to the critical charging condition (e.g., corresponds to this). The first control device may further be configured to request the charging determiner to complete (e.g., terminate) the charging. The charging determiner may be configured to request the second control device to deactivate the relay based on the request for charging completion. The charging determiner may be configured to initialize the charging interval (e.g., restart the charging interval (e.g.,to start again by checking whether the current time corresponds to the end of the charging interval or whether an elapsed time corresponds to the duration of the charging interval)).

[0017] According to the present invention, first, an expected lifetime of the auxiliary battery can be increased by preventing performance deterioration of the auxiliary battery by determining whether charging of the auxiliary battery is required based on a state of the vehicle, a state of the main battery, and a state of the auxiliary battery.

[0018] Secondly, according to the present invention, a problem of engine start inability (e.g., engine inability to start / start) can be solved by preventing discharge of the auxiliary battery by charging the auxiliary battery even if the electric vehicle is left in an engine-off state for a long time.

[0019] Thirdly, according to the present invention, cost reduction and reduction of maintenance and repair expenses can be achieved by improving the durability of the auxiliary battery.

[0020] Fourthly, according to the present invention, a voltage can be supplied from the auxiliary battery for an extended period of time even in an engine-off state.

[0021] It is to be understood that the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended only to provide further explanation of the invention as claimed. Short description of the drawings

[0022] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate an exemplary embodiment (or exemplary embodiments) of the invention and, together with the description, serve to explain the principle of the invention. In the drawings: is Fig. 1 is a block diagram illustrating an auxiliary battery charging control device according to an exemplary embodiment of the present invention; is Fig. 2 is a flowchart illustrating a periodic charging mode in an auxiliary battery charging control method according to an exemplary embodiment of the present invention; is Fig. 3 is a flowchart illustrating an automatic charging mode in the auxiliary battery charging control method according to an exemplary embodiment of the present invention; is Fig. 4 is a diagram illustrating effects obtained by the charging time control according to an exemplary embodiment of the present invention; is Fig. 5 is a diagram illustrating effects obtained by the charging voltage control according to an exemplary embodiment of the present invention; and is Fig. 6 is a diagram illustrating effects obtained by the charging interval control according to an exemplary embodiment of the present invention. Detailed description

[0023] It is to be understood that the terms "vehicle" or "vehicle-..." or any similar term used herein includes motor vehicles in general, such as passenger vehicles, including so-called sport utility vehicles (SUVs), buses, trucks, numerous commercial vehicles, watercraft, including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels produced from resources other than petroleum). A hybrid vehicle, as referred to herein, is a vehicle that has two or more power sources, e.g., vehicles that run on both gasoline and electricity.

[0024] Although an example embodiment is described as using a plurality of units to perform the example operation, it is to be understood that the example operations may also be performed by one (e.g., a single) or a plurality of modules. Furthermore, it is to be understood that the term controller / controller refers to a hardware device including a memory and a processor. The memory is configured to store the modules, and the processor is specifically configured to execute the modules to perform one or more operations described further below.

[0025] Furthermore, control logic of the present invention may be embodied as a non-transitory, computer-readable medium on a computer-readable medium containing executable program instructions executed by a processor, controller, or the like. Examples of the computer-readable medium include, but are not limited to, ROM, RAM, compact disk (CD)-ROMs, magnetic tapes, floppy disks, flash memory, memory cards, and optical data storage devices. The computer-readable recording medium may also be distributed in network-connected computer systems such that the computer-readable medium is stored and executed in a distributed manner, e.g., by means of a telematics server or a controller area network (CAN).

[0026] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms "a," "an," and "the," "which," as used herein, are intended to include the plural forms, unless the context clearly indicates otherwise. Further, it is to be understood that the terms "comprising" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, acts, elements, and / or components, but do not preclude the presence or addition of one or more additional features, integers, steps, acts, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated enumerated items.

[0027] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same or similar elements are denoted by the same reference numerals regardless of the symbols in the drawings, and redundant descriptions thereof will be omitted. The suffixes "-module" and "-unit" of the elements are used herein to simplify the description and thus can be used interchangeably (e.g., with each other) and have no different meanings or functions.

[0028] In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted if it might obscure the subject matter of the present invention.

[0029] Charging a battery can be specifically divided into initial charging (e.g., initial charging) and auxiliary charging (e.g., recharging). Initial charging can be performed under the condition that an electrolyte solution is disposed in the battery when the battery is initially used after manufacture to activate battery terminal plates. Auxiliary charging can be performed to replenish electrical energy consumed due to self-discharge of the battery or during use of the battery. In the present invention, auxiliary charging indicates auxiliary charging (e.g., recharging) for maintaining the state of charge of the auxiliary battery at a predetermined level or higher. Hereinafter, the terms auxiliary charging and recharging are used to have the same meaning.

[0030] In the present invention, the auxiliary battery can be operated to be automatically charged in an ignition 1 ON state (or an IG 1 ON state (where "IG" stands for "ignition")) taking into account the state of the auxiliary battery (hereinafter referred to as an "automatic charging mode"), and to be periodically charged in an ignition 1 OFF state (or an IG 1 OFF state) (hereinafter referred to as a "periodic charging mode"). In addition, the present invention takes into account a vehicle state, a main battery state, and an auxiliary battery state. Specifically, the present invention performs control operations to change a charging time (e.g., a charging time), a charging voltage, and a charging interval (e.g., a time between charges) based on changes in the auxiliary battery state.

[0031] In an exemplary embodiment of the present invention, an auxiliary battery charging control device may include a charging determiner configured to determine a vehicle state and a charging prohibition condition, a first controller configured to determine (e.g., calculate) a charging requirement based on a state of the auxiliary battery, and a second controller configured to operate (e.g., actuate) a relay of the main battery and an output of the main battery.

[0032] Hereinafter, a configuration of an auxiliary battery charging control device according to the present invention will be described with reference to Fig. 1. With reference to Fig. 2 and Fig. 3, a periodic charging mode and an automatic charging mode in an auxiliary battery charging control method according to the present invention are described, respectively. Furthermore, effects obtained according to the application of the auxiliary battery charging control method and the auxiliary battery charging control device are described with reference to Fig. 4 to 6.

[0033] Fig. 1 is a block diagram illustrating the auxiliary battery charging control device according to the illustrated exemplary embodiment of the present invention. Referring to Fig. 1, the auxiliary battery charging control device according to the illustrated exemplary embodiment of the present invention may include: a charging detector 100, a first controller 200, a second battery sensor 300, a second controller 400, a second battery 500 (hereinafter referred to as an “auxiliary battery”), a first battery 600 (hereinafter referred to as a “main battery”), and a relay 700.

[0034] The Fig. The components shown in Figure 1 as such are not essential to the auxiliary battery charging control device, and the auxiliary battery charging control device may be implemented using an increased or reduced number of components compared to the components described above. The components described above will be described in detail below.

[0035] The charging determiner 100 may be configured to determine whether a current charging mode is a periodic charging mode or an automatic charging mode based on an ignition voltage (IG voltage) applied to the charging determiner 100. When an ignition 1 voltage (or IG-1 voltage) applied to the charging determiner 100 is / is changed to an OFF state (e.g., switched), the periodic charging mode may be performed (e.g., the OFF state of the IG-1 voltage corresponds to a "first ignition voltage"). Furthermore, when the IG-1 voltage applied to the charging determiner 100 is / is changed to the ON state (e.g., switched), an automatic charging mode may be performed. The charging determiner 100 may be configured to calculate a charging interval of the periodic charging mode when the IG-1 voltage is changed (e.g., switched) to an OFF state.The charging determiner 100 may be configured to initiate (e.g., start) the periodic charging mode when the current time corresponds to the calculated charging interval (e.g., when a current time corresponds to a value of the charging interval or an elapsed time corresponds to the length of a calculated charging interval).

[0036] In an exemplary embodiment, the charging determiner 100 may be configured to count the current time (e.g., calculate an elapsed time) using a real-time clock (RTC) when the IG-1 voltage applied to the charging determiner 100 has / may have changed to an OFF state (e.g., switched) in order to determine whether the current time corresponds to the calculated charging interval. The charging determiner 100 may be configured to activate a relay when the current time corresponds to the calculated charging interval in order to switch on a separate control voltage to perform the periodic charging mode. The charging determiner 100 may further be configured to count a state of the vehicle (e.g., first state information) and a state of the main battery 600 (e.g.,a second state information) and to determine, based on the monitored results, whether a charging prohibition condition has been fulfilled (e.g., whether a charging prohibition condition applies).

[0037] In addition, the charging determiner 100 may be configured to monitor whether the current gear position (or the current gear) of the vehicle corresponds to a parking position (P-position), whether a charger (e.g., a charging device) is connected to the vehicle, whether doors, a hood, a tailgate, etc. of the vehicle are closed, and other conditions to determine whether charging is permitted. The charging determiner 100 may further be configured to monitor a temperature, a voltage, and a current of the main battery, a condition of the main battery 600, e.g., a state of charge (SOC) of the main battery 600, etc., to determine whether the charging amount (e.g., the charging quantity) of the main battery 600 is insufficient, in order to consequently determine whether a charging prohibition condition has been met (e.g., reached). The charging determiner 100 may be configured, in response to determining that the charging prohibition condition has been met (e.g.,reached) to block or prevent (e.g. prohibit) charging of the auxiliary battery 500.

[0038] The charging detector 100 may be further configured to request the second controller 400, in response to determining that no charging prohibition condition has been met (e.g., reached), to turn on the relay 700 and allow the first controller 200 to perform the charging. The charging detector 100 may be configured, in response to determining that a charging prohibition condition has been met (e.g., reached), to terminate the charging after the determination under the control of the second controller (e.g., the second switch) 400 and turn off the relay 700, which is set to turn on the separate control voltage for performing the periodic charging mode (e.g., the relay 700 is set to turn on the separate control voltage for performing the periodic charging mode before turning off).

[0039] The charging detector 100 may be configured to reset the charging interval stored in the RTC after charging is complete, or to set (e.g., adjust) the charging interval based on a change in the second battery state (or the state of the second battery). For example, the charging detector 100 may be configured to change (e.g., shorten) the charging interval if a voltage drop (e.g., a voltage dip) of the second battery 500 increases due to aging of the second battery or an increase in the leakage current (e.g., creepage current, leakage current, dark current) in order to shorten the charging interval and prevent discharge.

[0040] In an exemplary embodiment, the charging determiner 100 may be a hybrid control unit (HCU) or a vehicle control unit (VCU). The HCU (VCU), which is a main processing unit of an electric vehicle, may be configured to operate: a battery management system (BMS) to manage a main battery (or a high-voltage battery), to calculate the state of charge of the main battery, to perform current and voltage monitoring for the main battery, etc., thereby maintaining the main battery under optimal conditions, a low-current direct current (DC-DC) converter (LDC) configured to manage (e.g., manage, supervise) an auxiliary battery based on conditions of the main battery, wherein the consumed amount of electrical element voltage (e.g.,12V) is calculated to thereby adjust the electric element voltage, an engine control unit (ECU) which is configured to start an internal combustion engine for self-generation (e.g., for self-power generation) and to adjust an air intake amount by an electronic throttle control (ETC) to thereby adjust an output power of the internal combustion engine, a torque control unit (e.g., a transmission control unit) (TCU) which is configured to adjust a gear ratio (e.g., of a transmission), wherein a regenerative braking amount is determined by transmitting the output information to a power source, and an electric motor control unit (MCU) which is configured to perform control operations for transmitting an electric motor torque command, for electricity generation, and for maintaining the batteries in an optimal state of charge.The HCU (VCU) may be configured to distribute vehicle drive power and execute vehicle operating modes through the control operations described above.

[0041] The first controller 200 may be configured to monitor a state of the auxiliary battery 500 to determine whether the state of charge of the auxiliary battery 500 is equal to or lower than a predetermined level. The first controller 200 may be configured, in response to determining that the state of charge of the auxiliary battery 500 is equal to or lower than a predetermined level, to request the charging determiner 100 to allow charging. In particular, the first controller 200 may be configured to change one (e.g., exactly one) of a charging voltage and a charging time based on a degree of state change of the auxiliary battery 500.

[0042] In an exemplary embodiment, the first controller 200 may be configured to determine whether charging is required by comparing a state (e.g., third state information) of the auxiliary battery 500 with critical charging conditions. The critical charging conditions may be conditions regarding whether the voltage of the auxiliary battery 500 is lower than a predetermined threshold voltage (e.g., a periodic charging allowable voltage (e.g., a voltage at which periodic charging is permitted / allowable)) and whether an SOC of the auxiliary battery 500 is lower than a predetermined critical SOC. The first controller 200 may be configured to complete (e.g., terminate) charging and request that the charging determiner 100 initialize (e.g., restart) the charging interval when a state of the auxiliary battery 500 meets a predetermined level.

[0043] The first control device 200 may be a low-voltage DC-DC converter (LDC) (hereinafter referred to as an "LDC"). The LDC is a DC-DC converter configured to convert a DC input voltage into an output voltage having a DC voltage different from the DC input voltage.

[0044] In addition, the LDC may be configured to monitor a state of charge of the auxiliary battery 500 and to adjust charging of the auxiliary battery 500 based on the monitored results.

[0045] The second battery sensor 300 is a sensor configured to monitor the condition of the auxiliary battery 500. The second battery sensor 300 may be configured to transmit auxiliary battery condition information generated based on the monitored results to the first controller 200. Furthermore, the second battery sensor 300 may be an intelligent battery sensor (IBS). The IBS may be configured to detect a voltage, current, temperature, SOC, and state of health (e.g., state of aging) (SOH) of the associated battery and may be configured to transmit the detected information to the LDC.

[0046] The second control device 400 may be configured to turn on the relay 700 in response to receiving a relay ON request from the charge detector 100 and then transmit information indicating the ON state of the relay 700 to the charge detector 100. The first control device 200 may be configured to output electrical power or energy from the main battery 600 required to charge the auxiliary battery 500 when the relay 700 is in the ON state (e.g., the first control device 200 may electrically connect the main battery 600 to the auxiliary battery 500 and thereby convert a voltage of the main battery 600 into a voltage suitable for charging the auxiliary battery 500). In particular, the second control device 400 may be configured to continuously transmit a state of the main battery 600, e.g., the SOC, to the charge detector 100.

[0047] In an exemplary embodiment, the second control device 400 may be a battery management system (BMS). The BMS is a system configured to manage (e.g., manage, supervise) the associated battery to eliminate a possibility of explosion caused by overcharging, overheating, or external shock. Large-capacity batteries are generally separately equipped with a BMS. For electric vehicles, a BMS is also provided. The BMS may be configured to monitor a state of the associated battery represented by various information. Information representing the battery state may include (e.g., include): a voltage, a temperature, a SOC, a state of health (e.g., a state of aging) (SOH), an air flow, a current input / output state (e.g.,a state indicating whether and to what extent an electric current is flowing into or out of the battery), etc. of the associated battery. The BMS may also be configured to perform a calculation required to supply electrical power or energy from the battery based on the information described above, and may be configured to communicate with an external device to receive and transmit various information under the condition that the BMS is connected to the external device.

[0048] The second battery 500 and the first battery 600 may be the auxiliary battery and the main battery, respectively (e.g., the second battery 500 may be the auxiliary battery and the first battery 600 may be the main battery). In the following description, a detailed description of the second battery 500 and the first battery 600 will not be given, since the second battery 500 and the first battery 600 have been described in detail above. The relay 700 may be configured to connect or disconnect the first controller 200 and the first battery 600 based on whether charging is required (e.g., electrically). In an exemplary embodiment, the relay 700 may be turned on or off by actuation of the second controller 400 to allow or prevent charging.

[0049] Fig. 2 is a flowchart illustrating a periodic charging mode in an auxiliary battery charging control method according to an exemplary embodiment of the present invention. In the periodic charging mode, in an OFF state of an IG-1 voltage, a charge level of the auxiliary battery may be monitored at intervals of a predetermined time. When the charge level of the auxiliary battery is equal to or lower than a predetermined level, a control operation may be performed to maintain the charge level of the auxiliary battery at the predetermined level using the main battery.

[0050] In the periodic charging mode, a charging time, a charging voltage, and a charging interval can be adjusted based on a change in the auxiliary battery state. As a result, a discharge caused by aging of the secondary battery or an increase in leakage current (e.g., creepage current, leakage current, dark current) can be corrected. For example, if the vehicle is left in an engine-OFF state for a significant (e.g., a significant) period of time, charging of the auxiliary battery can be performed periodically in the periodic charging mode under the condition that the charging time, charging voltage, and charging interval are changed.

[0051] Referring to Fig. 2, the charging determiner 100 may be configured to compare a calculated value of the RTC corresponding to the current time with a charging interval when the IG-1 voltage is switched to an OFF state to determine whether the current time corresponds to the charging interval (S100). If the current time corresponds to the charging interval, a third IG voltage (IG-3 voltage) (e.g., an activation voltage) may be turned on (e.g., applied). The first controller 200 may be activated by the third IG voltage, and the charging determiner 100 may be configured to determine a charging mode (S110). In other words, the charging determiner 100 may be configured to distinguish a periodic charging mode and an automatic charging mode based on the voltage applied thereto.

[0052] In an exemplary embodiment, the charging detector 100 may be configured to distinguish the periodic charging mode corresponding to the first IG voltage and transmit information representing a distinguishing possibility of the periodic charging mode to the first controller, which in turn may be configured to identify the periodic charging mode (S200). The first controller 200 may further be configured to determine a state of the second battery 500 to determine whether the determined state of the second battery 500 corresponds to a critical charging condition.

[0053] The first controller 200 may also be configured to determine whether the determined state of the second battery 500 corresponds to the critical charging condition based on whether the voltage of the second battery 500 is lower than a predetermined voltage (e.g., a charging allowable voltage) or whether the SOC of the second battery 500 is lower than a charging allowable SOC. If the determined state of the second battery 500 corresponds to the critical charging condition, the first controller 200 may be configured to request that the charging determiner 100 perform the periodic charging (S220).

[0054] The charging determiner 100 may be configured to determine, in response to receiving a charging request from the first controller, whether the state of the vehicle and the state of the first battery 600 correspond to a charging prohibition condition (S120). The charging prohibition condition may be met (e.g., satisfied) if, based on signals from a door opening switch or sensor, a hood opening switch, a tailgate opening switch, etc., it is determined that doors, a hood, a tailgate, etc., are open.of the vehicle are closed when the voltage of the first battery 600 is lower than a predetermined voltage, when the SOC of the first battery 600 is lower than a predetermined SOC, when charging has been continuously performed a predetermined number of times or more, or when, after monitoring for a predetermined period of time after charging, the voltage of the second battery 500 remains lower than a predetermined voltage or the SOC of the first battery 600 remains lower than the predetermined SOC.

[0055] The charging detector 100 may be configured to request the second controller 400 to turn on the relay 700 (S130) if the charging detector 100 determines that the state of the vehicle and the state of the first battery 600 do not correspond to the charging prohibition condition. The charging detector 100 may be configured to transmit a signal representing permission for charging based on the turning on of the relay 700 to the second controller 400 (S140) at the same time as requesting to turn on the relay 700. The first controller 200 may then be configured to charge the second battery 500 and simultaneously perform a control operation related to the charging time and the charging voltage (e.g., a control operation in which the charging time and the charging voltage are changed) (S230).

[0056] The control operation of the first control device 200, which is related to the charging time and the charging voltage, will be described in detail with reference to Fig. 4 to 6. The first controller 200 may be configured to complete charging and request that the charging determiner 100 initialize (e.g., restart) the charging interval (S240) when the first controller 200 determines, after monitoring the state of the second battery 500, that the voltage of the second battery 500 is greater than the charging allowable voltage, the SOC of the second battery 500 is greater than the predetermined SOC, or the charging time is greater (or longer) than a predetermined time. The charging determiner 100 may then be configured to initialize (e.g., reset) the RTC to initialize (e.g., reset) the charging interval and operate the second controller 400 to turn off the relay 700 (S160).

[0057] Fig. 3 is a flowchart illustrating an automatic charging mode in the auxiliary battery charging control method according to the illustrated exemplary embodiment of the present invention.

[0058] In the automatic charging mode, in an ON state of the IG-1 voltage, a charge level of the auxiliary battery can be monitored. If the charge level of the auxiliary battery is equal to or lower than a predetermined level, a control operation can be performed to maintain the charge level of the auxiliary battery at the predetermined level using the main battery. Furthermore, the charging time and the charging voltage can be adjusted based on the change in the auxiliary battery state. As a result, discharge caused by aging of the secondary battery or an increase in leakage current can be corrected.

[0059] Referring to Fig. 3, the first control device 200 may be configured to obtain information regarding the state of the second battery 500 from the second battery sensor 300 and determine the state of the second battery 500 based on the obtained information, thus determining whether the state of the second battery 500 corresponds to a critical charging condition (S400).

[0060] In an exemplary embodiment, the first controller 200 may be configured to determine whether the determined state of the second battery 500 corresponds to the critical charging condition based on whether the voltage of the second battery 500 is lower than a predetermined voltage (e.g., a charging allowable voltage) or whether the SOC of the second battery 500 is lower than a charging allowable SOC.

[0061] The first controller 200 may be configured to request that the charging determiner 100 perform automatic charging (S410) when the determined state of the second battery 500 corresponds to the critical charging condition. The charging determiner 100 may be configured to determine, in response to receiving the charging request from the first controller 200, whether the state of the vehicle or the state of the first battery 600 corresponds to a charging prohibition condition (S300).

[0062] In an exemplary embodiment, the charging prohibition condition may be (e.g., satisfied) when it is determined that doors, a hood, a tailgate, etc. of the vehicle are closed based on signals from a door opening switch (e.g., a (door opening) sensor), a hood opening switch, a tailgate opening switch, etc., when the voltage of the first battery 600 is lower than a predetermined voltage, when the SOC of the first battery 600 is lower than a predetermined SOC, when charging has been continuously performed a predetermined number of times or more, or when, after monitoring for a predetermined period of time after charging, the voltage of the second battery 500 remains lower than a predetermined voltage or the SOC of the first battery 600 remains lower than the predetermined SOC.

[0063] The charging determiner 100 may be configured to request that the second controller 400 turn on the relay 700 (S320) when the charging determiner 100 determines that the state of the vehicle and the state of the first battery 600 do not correspond to the charging prohibition condition (S310). The charging determiner 100 may be configured to transmit a signal representing permission for charging based on the turning on of the relay 700 to the second controller 400 at the same time as requesting to turn on the relay 700 (S330).

[0064] The first control device 200 may be configured to perform the charging of the second battery 500 and simultaneously perform a control operation related to the charging time and the charging voltage (S430). The first control device 200 may in particular be configured to complete charging (e.g., the control operation) and request that the charging determiner 100 initialize the charging interval (S440) if the first control device 200 determines, after monitoring the state of the second battery 500, that the voltage of the second battery 500 is greater than the charging allowable voltage, the SOC of the second battery 500 is greater than the predetermined SOC, or the charging time exceeds (e.g., exceeds) a predetermined time. The charging determiner 100 may then be configured to initialize (e.g., reset) the RTC to initialize the charging interval (e.g.,reset), and actuate the second control device 400 to turn off the relay 700 (S340).

[0065] Fig. 4 is a diagram illustrating the effects obtained by charging timing control according to an exemplary embodiment of the present invention. Fig. 5 is a diagram illustrating the effects obtained by charging voltage control according to an exemplary embodiment of the present invention. Fig. 6 is a diagram illustrating the effects obtained by charging interval control according to an exemplary embodiment of the present invention.

[0066] The charging time control and the charging voltage control may be performed by the first controller 200, whereas the charging interval control may be performed by the charging detector 100. Recently developed vehicles have a tendency toward an increase in the number of electrical elements. A leakage current (e.g., a creepage current, a leakage current, a dark current) may consequently be increased. In addition to an increase in the leakage current, a voltage drop (e.g., a voltage dip) of an auxiliary battery may increase due to aging of the auxiliary battery. In the present invention, therefore, a change in the voltage drop of the auxiliary battery can be monitored and, consequently, it can be compensated by extending the charging time, increasing the charging voltage, and decreasing (e.g.,Shortening) the charging interval based on the monitored results may be possible to prevent the auxiliary battery voltage from decreasing below a minimum start enable voltage.

[0067] The above-described exemplary embodiments of the present invention may be implemented as code that can be written on a storage medium that can be read by a processor provided in the device (e.g., the vehicle's control device) and that can be read by the processor. The storage medium that can be read by a processor may include all types of storage media on which processor-readable data is written, such as a hard disk drive (HDD), a solid-state drive (SSD), a silicon disk drive (SDD), a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and a carrier wave type (e.g., a transmission over the Internet).

[0068] The non-transitory, computer-readable storage medium is distributed among computer systems connected via a network, and computer-readable code can be stored and executed in a distributed manner. Furthermore, a functional program, code, and code portions for implementing the method described above can be easily derived by programmers in the technical field to which the present invention belongs (e.g., from the above description and the figures).

[0069] Those skilled in the art will recognize that the effects that can be achieved by the present invention are not limited to what has been particularly described above, and other advantages of the present invention will be more clearly understood from the above detailed description.

[0070] Those skilled in the art will recognize that numerous modifications and variations can be made to the present invention without departing from the scope of the invention. Accordingly, it is intended that the invention cover the modifications and variations of this invention, provided they come within the scope of the appended claims.

Claims

[1] A battery charging control method comprising: Determining by a charging determiner (100) whether a charging prohibition condition has been met based on first state information of a vehicle and second state information of a first battery (600) at a charging interval of a predetermined time period (S120) when the charging determiner (100) performs a periodic charging mode based on a first ignition voltage (IG voltage) applied thereto, Performing charging by the charging determiner (100) based on a determination result based on third state information of a second battery (500) (S300 - S330) by a first control device (200) as to whether a critical charging condition has been met when the charging determiner performs an automatic charging mode based on a second IG voltage applied thereto, Calculating a voltage change of the second battery (500) selected from the third state information by the first control device (200) and setting at least one of a charging time and a charging voltage by the first control device (200) based on the calculated voltage change or setting the charging interval by the charging determiner (100) based on the calculated voltage change, Determining by the charging detector (100) based on the applied IG voltage whether execution of the automatic charging mode or the periodic charging mode is required (S110), Activating a relay (700) by a second control device (400) (S130, S320) and carrying out charging of the second battery (500) by the first control device (200) (S230, S430) when the third state information corresponds to the critical charging condition, wherein the activation of the relay (700) by the second control device (400) (S130, S320) and the carrying out of the charging of the second battery (500) by the first control device (200) (S230, S430) when the third state information corresponds to the critical charging condition comprises: Requesting, by the first control device (200), the charging detecting means (100) to allow charging if the third state information corresponds to the critical charging condition (S220, S410), and Requesting, by the charging detecting means (100), the second control means (400) to activate the relay (700) based on the charging permission request (S130, S330). [2] The battery charging control method according to claim 1, further comprising: Completing the charging of the second battery (500) by the first control device (200) (S240, S440) when the third state information exceeds the critical charging condition. [3] The battery charging control method according to claim 1 or 2, further comprising: Transmitting, by the charging determiner (100), information regarding the determined charging mode to the first control device (200) (S140, S330) when the at least one of the first state information and the second state information does not correspond to the charging prohibition condition. [4] The battery charging control method according to any one of claims 1 to 3, wherein the activation of the relay (700) by the second control means (400) (S130, S320) and the carrying out of the charging of the second battery (500) by the first control means (200) (S230, S430) when the third state information corresponds to the critical charging condition comprises: Obtaining, by the first control device (200), the third state information of the second battery (500) from a second battery sensor (300), and Determining, by the first control device (200), whether the third state information corresponds to the critical charging condition (S210, S400). [5] The battery charging control method according to any one of claims 1 to 4, wherein the completion of charging of the second battery (500) by the first control means (200) when the third state information exceeds the critical charging condition comprises: Requesting, by the first control device (200), the charging detecting means (100) to complete the charging (S240, S440), and Requesting, by the charging detecting means (100), the second control means (400) to deactivate the relay (700) based on the charging completion request (S150). [6] The battery charging control method according to claim 5, wherein the completion of charging of the second battery (500) by the first control means (200) when the third state information exceeds the critical charging condition comprises: Initializing the charging interval by the charging detector (100) (S160, S340). [7] A battery charging control device comprising: a charging determiner (100) configured to determine, based on first state information of a vehicle and second state information of a first battery at a charging interval of a predetermined time period, whether a charging prohibition condition has been met in response to performing a periodic charging mode based on a first ignition voltage (IG voltage) applied thereto, and configured to perform charging using third state information of a second battery (500) based on whether a critical charging condition has been met when the charging determiner (100) performs an automatic charging mode based on a second IG voltage applied thereto, and a first control device (200) which is configured to calculate a voltage change of the second battery (500) selected from the third state information and to set at least one of a charging time and a charging voltage based on the calculated voltage change, wherein the charging detector (100) is configured to adjust the charging interval based on the calculated voltage change, wherein the charging detector (100) is configured to determine, based on the applied IG voltage, whether execution of the automatic charging mode or the periodic charging mode is required, wherein the battery charging control device further comprises a second control device (400) which is configured to activate a relay (700), wherein the first control device (200) is configured to carry out charging of the second battery (500) when the third state information corresponds to the critical charging condition, wherein the first control device (200) is configured to request the charging determiner (100) to permit charging if the third state information corresponds to the critical charging condition, and wherein the charging determiner (100) is configured to request the second control device (400) to activate the relay (700) based on the request for charging permission. [8] The battery charging control device according to claim 7, wherein the first control means (200) is arranged to complete the charging of the second battery (500) when the third state information exceeds the critical charging condition. [9] The battery charging control device according to claim 7 or 8, wherein the charging determiner (100) is configured to transmit information based on the determined charging mode to the first control device (200) when the at least one of the first state information and the second state information does not correspond to the charging prohibition condition. [10] The battery charging control device according to any one of claims 7 to 9, further comprising: a battery sensor (300) which is configured to transmit the third status information of the second battery (500) to the first control device (200), wherein the first control device (200) is configured to determine whether the third state information corresponds to the critical charging condition. [11] The battery charging control device according to any one of claims 7 to 10, wherein the first control means (200) is configured to request the charging determiner (100) to complete charging, and wherein the charging determiner (100) is configured to request the second control means (400) to deactivate the relay (700) based on the charging completion request. [12] The battery charging control device according to any one of claims 7 to 11, wherein the charging determiner (100) is arranged to initialize the charging interval.

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