Battery charging control method and system

Abstract

A battery charging control method, the method comprising: when a vehicle is turned on, turning on a switch (70) to charge a battery (30); if a state of charge (SOC) of the battery (30) is greater than a preconfigured value, turning off the switch (70) for a first time interval calculated on the basis of an estimated destination arrival time derived from the navigation device (90); and Switching the switch (70) back on at a time when the first time interval has elapsed, wherein the switch (70) is switched on again to charge the battery (30) for a second time interval, wherein the estimated destination arrival time is a time period from a time of turning off the switch (70) to a time of arrival, wherein the first time interval is determined based on the estimated destination arrival time, a charging power, a discharging power, and a load.

Description

Technical area

[0001] The present invention relates to a method and system for controlling battery charging. background

[0002] In the case of a hybrid vehicle and an electric vehicle, an electrical load and an auxiliary battery are connected in parallel to an output terminal of a low-voltage DC-DC converter (hereinafter referred to as LDC). Generally, an LDC operates whenever a vehicle is moving, and even when the auxiliary battery is fully charged, the LDC continues to charge the auxiliary battery. Accordingly, the resulting energy loss leads to inefficiency.

[0003] Furthermore, it is ideal to keep an auxiliary battery as fully charged as possible when a vehicle is not moving to prevent it from discharging. However, with conventional technology, since it is unknown when the vehicle will stop, an auxiliary battery is continuously charged, resulting in some energy loss. Accordingly, an LDC continuously supplies energy even when the auxiliary battery is fully charged, resulting in energy loss.

[0004] Therefore, a solution is desirable to reduce the energy loss of an LDC by controlling the charging process of an auxiliary battery and to improve fuel consumption by ensuring that a vehicle has the best state of charge (hereinafter referred to as SOC) when the vehicle is stationary.

[0005] DE 601 33 446 T2 discloses an apparatus for controlling a hybrid electric vehicle in which a rechargeable battery is discharged to drive an electric motor to cause the hybrid electric vehicle to travel, and in which the rechargeable battery is charged with regenerative electric power from the electric motor. The apparatus includes a vehicle navigation device for outputting route information on a route to a destination of the vehicle, including altitude information; and a control section for controlling the charging and discharging of the rechargeable battery.

[0006] DE 10 2016 108 358 A1 discloses an auxiliary battery charging control method and an auxiliary battery charging control device. The method comprises: determining 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 regular charging intervals when a periodic charging mode is performed based on a first ignition voltage (IG voltage). Charging is performed based on whether a critical charging condition has been met using third state information of a second battery; an automatic charging mode is performed based on a second IG voltage.

[0007] The above description in this Background section is provided merely to provide a better understanding of the background of the present disclosure and is not intended as an acknowledgment that the information constitutes prior art that is already known to one skilled in the art. Summary

[0008] The present invention provides a battery charge control method and system as defined in claims 1 and 5, respectively. Particular embodiments relate to a battery charge control method and system that uses navigation information to determine a time at which a vehicle will stop. When the vehicle is stopped, the system controls an auxiliary battery to be charged as fully as possible to prevent the battery from becoming discharged and to prevent energy from flowing into the auxiliary battery when the auxiliary battery is fully charged, thereby maximizing fuel consumption.

[0009] Embodiments of the present invention solve the problems described above. One aspect of the present invention is to provide a battery charging control method and system that uses navigation information to determine a time at which a vehicle will stall. When the vehicle stalls, the system controls an auxiliary battery to maintain the fullest possible charge.

[0010] Turning off the switch includes the steps of turning off the switch and adjusting the output voltage of a DC-DC converter according to the size of an electrical load electrically connected to the battery in parallel with an output terminal of the DC-DC converter.

[0011] Turning off the switch also involves calculating the first time interval using an equation: first time interval=T×(Pchg−2Pdiff−Pload) / (Pchg−Pdiff−Pload), where T indicates the estimated destination arrival time interval, P chg indicates a charging power, P diff indicates a discharge power and P load indicates a load.

[0012] Turning off the switch further involves calculating the second time interval using an equation: second time interval=T×(Pdiff) / (Pchg−Pdiff−Pload), where T is the estimated arrival time, P chg indicates a charging power, P diff indicates a discharge power and P load indicates a load.

[0013] The system further comprises an electrical load electrically connected together with the battery in parallel to an output terminal of the DC-DC converter, wherein the control unit is configured to turn off the switch for the first time interval and adjust the output voltage of the DC-DC converter when an SOC of the battery becomes greater than the preconfigured value, wherein the output voltage is adjusted according to the size of the electrical load.

[0014] The control unit calculates the first time interval using an equation: first time interval=T×(Pchg−2Pdiff−Pload) / (Pchg−Pdiff−Pload), where T is the estimated destination arrival time, P chg indicates a charging power, P diff indicates a discharge power and P load indicates a load.

[0015] The control unit calculates the second time interval using an equation: second time interval = T × (Pdiff) / (Pchg − Pdiff − Pload) where T is the estimated destination arrival time, P chg indicates a charging power, P diff indicates a discharge power and P load indicates a load.

[0016] A battery charging control method and system according to an embodiment of the present invention uses navigation information to determine a time at which a vehicle stops, wherein, when the vehicle stops, an auxiliary battery is charged as fully as possible to prevent the battery from being discharged and to prevent energy from flowing into the auxiliary battery when the auxiliary battery is fully charged, thereby maximizing fuel consumption.

[0017] Likewise, the method and system minimize the power consumption of an LDC, thereby minimizing the energy consumption of a main battery.

[0018] In addition, the method and system fully charge an auxiliary battery, then turn off a switch of the auxiliary battery and allow a voltage of an electrical load to be variably controlled by an LDC, thereby improving fuel consumption.

[0019] Furthermore, the method and system can maximize the use of variable voltage control for an LDC by incorporating travel time extension due to traffic condition through time-based calculation.

[0020] In addition, the method and system maximize conventional variable voltage control by full charge control at an arrival point and maintaining a charge limit to maintain the fuel saving effect.

[0021] In addition, the method and system perform a fast full charge control instead of increasing a lower charge limit to minimize the fuel economy loss due to overcharging of an SOC.

[0022] Even if an electrical load is quickly switched near an arrival point, the electrical load remains unaffected because a relay is turned off after an auxiliary battery is fully charged. Therefore, it is possible to bring an auxiliary battery to a fully charged state upon arrival. Short description of the drawings

[0023] The above and other aspects, features and advantages of the present disclosure will be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings in which they are incorporated, in which: Fig. 1 is a configuration diagram of a battery charging control system according to an embodiment of the present invention; Fig. 2 is a flowchart of a battery charging control method according to an embodiment of the present invention; and Fig. 3 is a diagram for explaining a battery charge control method according to an embodiment of the present invention. Detailed description of illustrative embodiments

[0024] A battery charging control method and system will now be described with reference to the accompanying drawings and in accordance with various embodiments of the present invention.

[0025] Fig. 1 is a configuration diagram of a battery charging control system according to an embodiment of the present invention, Fig. 2 is a flowchart of a battery charge control method according to an embodiment of the present invention and Fig. 3 is a diagram for explaining a battery charge control method according to an embodiment of the present invention.

[0026] First, a battery charging control system according to an embodiment of the present invention may include a battery 30, a DC-DC converter 50 that converts a voltage level for charging the battery 30, and a switch 70 connected between the DC-DC converter 50 and the battery 30. A navigation device 90 is configured to receive a destination from a user to derive an estimated destination arrival time. A control unit 100 is configured to turn on the switch 70 to charge the battery 30 when a destination is entered into the navigation device 90 and a vehicle starts. When a state of charge (SOC) of the battery 30 becomes greater than a preconfigured value, the control unit 100 turns off the switch 70 for a first time interval calculated based on an estimated destination arrival time transmitted from the navigation device 90.The control unit 100 turns the switch 70 back on at a time when the first time interval has elapsed to charge the battery 30 for a second time interval.

[0027] The battery 30 may be an auxiliary battery that is powered by the DC-DC converter 50 and supplies electrical energy to an electrical load 110 described in an embodiment of the present invention.

[0028] In one embodiment of the present invention, DC-DC converter 50 may be a low-voltage DC-DC converter that converts a voltage level input from an on-board battery charger (OBC) and then outputs the voltage of the converted voltage level. DC-DC converter 50 is electrically connected to battery 30 and electrical load 110, respectively, to charge battery 30. When switch 70 is turned off, DC-DC converter 50 adjusts the output voltage according to the size of electrical load 110 to provide the set output voltage, which is described below.

[0029] Switch 70 is connected between DC-DC converter 50 and battery 30 and, in one embodiment of the present invention, may be a relay. Switch 70 is turned on and off by control unit 100. When switch 70 is turned on, battery 30 is charged. When switch 70 is turned off, battery 30 is blocked from electrical communication with DC-DC converter 50 and electrical load 110, thus naturally discharging.

[0030] The electrical load 110 may be electrically connected together with the battery 30 in parallel to an output terminal of the DC-DC converter 50.

[0031] The navigation device 90 is a device for identifying a current vehicle position from a Global Positioning System (GPS) satellite and providing information about a current geographical vehicle position, information about road and traffic conditions en route to a destination, and an estimated destination arrival time estimated based on geographical information mapped using the identified current vehicle position. According to one embodiment of the present invention, the navigation device 90 may be a navigation device installed in a vehicle or a mobile terminal (e.g., mobile phone and tablet device) connected to the vehicle via Bluetooth or a cable.

[0032] The control unit 100 can be implemented in various ways. For example, known hardware can be controlled with any control circuitry, e.g., with a microcontroller or a digital logic circuit implemented, e.g., in an application-specific integrated circuit (ASIC). In one example, the control unit 100 could include a processor and a non-transitory, computer-readable storage medium storing a program to be executed by the processor. The program could be based on the flowchart of Fig. 2 based.

[0033] When the navigation device 90 receives a destination and starts the vehicle, the control unit 100 turns on the switch 70 to charge the battery 30. Then, when a state of charge (SOC) of the battery 30 becomes greater than a preconfigured value, the control unit 100 turns off the switch 70 for a first time interval calculated based on an estimated destination arrival time transmitted from the navigation device 90. Then, at a time when the first time interval has elapsed, the control unit 100 turns the switch 70 back on to charge the battery 30 for a second time interval.

[0034] The preconfigured value is an SOC value preconfigured in the control unit 100. In one embodiment of the present invention, this value may range from 80 to 90% and may vary depending on the setting. The control unit 100 determines a fully charged state of the battery 30 when the SOC value of the battery 30 is greater than a preconfigured value. The control unit 100 then turns off the switch 70 to prevent energy loss due to additional charging of the fully charged battery 30.

[0035] The first time interval is a period in which the switch 70 is turned off, and means a period from a time when the control unit 100 turns off the switch 70 when an SOC of the battery 30 is greater than a preconfigured value to a time when the control unit 100 turns the switch 70 on again before the vehicle reaches a destination.

[0036] The first time interval can be derived using Equation 1 below. In Equation 1, T typically indicates an estimated arrival time of the destination, which is calculated by inputting a destination into the navigation device 90. However, an estimated destination arrival time for calculating a first and a second time interval according to the present invention may be a period of time from a time when the switch 70 is turned off to a time of arrival. That is, an estimated destination arrival time may refer to a time from a time when the switch 70 is turned off when an SOC of the battery 30 reaches a preconfigured value after the battery 30 is charged by the switch 70 turned on at the time of vehicle start-up to a time of arrival.

[0037] For example, if an estimated destination arrival time calculated for a destination input into the navigation device 90 is 60 minutes and 20 minutes until an SOC of the battery 30 reaches a preconfigured value after the switch 70 is turned on at the time of vehicle start-up, an estimated destination arrival time for calculating a first and a second time interval is calculated to be 40 minutes by subtracting 20 minutes from 60 minutes. P chg indicates a charging power that corresponds to the output power of the DC-DC converter 50. P diff denotes a discharge power corresponding to the power loss for a predefined time after switching off the switch 70 and maintaining the output power of the DC-DC converter 50, wherein the power loss is measured by a sensor connected to the battery 30. Furthermore, P diffbe derived by an average value measured for a given time from a point in time at which the switch 70 is turned off. P load indicates a load power that corresponds to the power consumed by a load. first time interval = T × (Pchg − 2 Pdiff − Pload) / (Pchg − Pdiff − Pload) In equation 1, T indicates the estimated destination arrival time, P chg the charging power, P diff the discharge power and P load indicates a charging power.

[0038] A second time interval is a period of time from a time when the switch 70 is turned on again before the vehicle arrives at the destination to a time when the vehicle arrives at the destination. The battery 30 is charged during the second time interval so as to be fully charged when the vehicle arrives at the destination. Thus, the battery 30 can be prevented from being discharged when the vehicle is stopped, so that deterioration in service life due to discharge of the battery 30 can be prevented. Furthermore, the battery 30 is fully charged before the vehicle arrives and thus has improved charging efficiency compared to charging the battery 30 when the vehicle is stopped.

[0039] The second time interval can be derived from the difference between the derived estimated target arrival time T and the first time interval. In particular, the second time interval can be derived using Equation 2 below. In Equation 2, T, P chg , P diff and P load each identical to T, P chg , P diff and P load in the above equation 1 to calculate the first time interval. second time interval = T × (Pdiff) / (Pchg − Pdiff − Pload)

[0040] In equation 2, T indicates the estimated destination arrival time, P chg the charging power, P diff the discharge power and P load the charging power.

[0041] The control unit 100 turns off the switch 70 for a first time interval when an SOC of the battery 30 is greater than a preconfigured value and adjusts the output voltage of the DC-DC converter 50 according to the size of the electrical load 110.

[0042] The control unit 100 turns off the switch 70 when the SOC of the battery 30 is greater than a preconfigured value to avoid energy losses due to additional charging of the fully charged battery 30. At the same time, the control unit 100 adjusts the output voltage of the DC-DC converter 50 to the size of the electrical load 110, thus improving the fuel economy of the vehicle.

[0043] The specific control operation of the control device 100 is described by the battery charge control method described below.

[0044] With reference to the Fig. 2 and Fig.3, a battery charging control method according to an embodiment of the present invention may also include the steps of: when a navigation device receives a destination and starts a vehicle, turning on a switch to charge a battery (S100 and S200); when a state of charge (SOC) of the battery becomes greater than a preconfigured value (X), turning off the switch during a first time interval (interval C) derived based on an estimated destination arrival time (interval T') sent from the navigation device (S300 and S400); and turning on the switch again at a time point (S2') at which the first time interval (interval C) has elapsed to charge the battery during a second time interval (interval D) (S700).

[0045] During the battery charging steps (S100 and S200), a user first enters a destination into the navigation device to calculate an estimated destination arrival time. Then, when the vehicle starts, the switch is turned on to charge the battery. The battery is charged until a SOC with a preconfigured value (X) is reached (interval A). The preconfigured value (X) is a preconfigured state of charge (SOC) as described above, may be 80-90% in one embodiment of the present invention, and may vary depending on the setting. A battery SOC that reaches a preconfigured value (X) may mean that the battery is fully charged.

[0046] As with the battery charging control system described above, the estimated destination arrival time is typically an estimated time (interval T) calculated when a user inputs a destination into the navigation device. However, according to the present invention, an estimated destination arrival time (interval T') for calculating first and second time intervals may be a time from a time (1') when the switch is turned off to a time (3') of arrival. That is, the estimated destination arrival time (interval T') may be a time period from a time (1') when the switch is turned off when an SOC of the battery reaches a preconfigured value after the battery is charged by the switch being turned on at the time of vehicle start-up to a time (3') of arrival.

[0047] When the switch is turned off for the first time interval (S300 and S400), the switch is turned off when the battery's SOC value exceeds a preconfigured value (X). Therefore, turning off the switch when the battery is fully charged can fundamentally block the energy loss caused by charging the fully charged battery. When the switch is turned off, the electrical load is supplied with power supplied by the DC-DC converter instead of the battery, and the output voltage of the DC-DC converter is adjusted according to the size of the electrical load, thus improving the vehicle's fuel consumption.

[0048] After the switch is turned off, the discharge power of the battery is measured for a predetermined time (interval B, which may vary depending on the setting). That is, the discharge power is measured as an average value measured for a predetermined time from a time when the switch 70 is turned off (S500). Then, based on the measured discharge power and an estimated destination arrival time (interval T') from a time (1') when the switch is turned off to a time (3') of arrival, the first time interval (interval C) in which the switch is turned off and the second time interval (interval D) from a time (2') when the switch is turned on again before the vehicle arrives at the destination to a time (3') of arrival at the destination are calculated (S600). The first time interval (interval C) and the second time interval (interval D) are calculated using the equations below. first time interval (interval C) = T × (Pchg − 2 Pdiff − Pload) / (Pchg − Pdiff − Pload) second time interval (interval D) = T × (Pdiff) / (Pchg − Pdiff − Pload)

[0049] In the equations, T indicates an estimated arrival time of the destination, P chg a charging power, P diff a discharge power and P load a charging power.

[0050] T, P chg , P diff and P load are identical to T, P chg , P diff and P load in equation 1 for calculating the first time interval (interval C) as described above in the battery charge control system.

[0051] As can be seen from the derived equations, the first time interval (interval C) in which the switch is turned off and the second time interval (interval D) in which the switch is turned on before the vehicle arrives at the destination can vary based on an estimated destination arrival time. The present invention therefore makes it possible to turn on a switch before the vehicle arrives at the destination to charge the battery while ensuring that the battery is fully charged upon the vehicle's arrival.

[0052] After the first time interval (Interval C) and the second time interval (Interval D) have elapsed, the switch is turned off for the calculated first time interval (Interval C). During the first time interval, the battery is barely affected by the electrical load because the switch is turned off, thus providing a small range of variation until the vehicle arrives.

[0053] In the battery charging operation for the second time interval (interval D) (S700), the switch is turned on again at a time (2') when the first time interval (interval C) has elapsed (S700) to charge the battery for the second time interval (interval D). Accordingly, the battery is fully charged by the time the vehicle arrives at the destination, preventing the battery from being discharged when the vehicle stops and further blocking the deterioration of the service life due to battery discharge. In addition, the battery is fully charged before the vehicle arrives, thus achieving improved charging efficiency compared to charging the battery when the vehicle stops.

[0054] As described above, a battery charge control method and system according to various embodiments of the present invention uses navigation information to determine a time point at which a vehicle stops; and when the vehicle stops, it controls an auxiliary battery to be as fully charged as possible to prevent the battery from being discharged and to prevent power from flowing to the auxiliary battery when the auxiliary battery is fully charged, thereby maximizing fuel consumption.

[0055] Likewise, the method and system minimize the power consumption of an LDC, thereby minimizing the energy consumption of a main battery.

[0056] In addition, the method and system fully charge an auxiliary battery, then turn off a switch of the auxiliary battery and enable variable control of a voltage of an electrical load by an LDC, which also improves fuel consumption.

[0057] Furthermore, the method and system can maximize the use of variable voltage control for an LDC by incorporating travel time extension due to traffic condition through time-based calculation.

[0058] In addition, the method and system maximize conventional variable voltage control by fully charging at an arrival point and maintaining a charge limit to maintain the fuel economy effect.

[0059] In addition, the method and system perform a rapid full charge control instead of increasing a lower charge limit to minimize the fuel consumption loss due to overcharging of an SOC.

[0060] Furthermore, even if an electrical load is quickly switched near an arrival point, the electrical load is not affected because a relay is turned off after an auxiliary battery is fully charged. Therefore, it is possible to bring an auxiliary battery to a fully charged state upon arrival.

Claims

[1] A battery charging control method, the method comprising: when a vehicle is turned on, turning on a switch (70) to charge a battery (30); if a state of charge (SOC) of the battery (30) is greater than a preconfigured value, turning off the switch (70) for a first time interval calculated on the basis of an estimated destination arrival time derived from the navigation device (90); and Switching the switch (70) back on at a time when the first time interval has elapsed, wherein the switch (70) is switched on again to charge the battery (30) for a second time interval, wherein the estimated destination arrival time is a time period from a time of turning off the switch (70) to a time of arrival, wherein the first time interval is determined based on the estimated destination arrival time, a charging power, a discharging power, and a load. [2] The method of claim 1, wherein turning off the switch (70) comprises the steps of turning off the switch (70) and adjusting the output voltage of a DC-DC converter (50) according to the size of an electrical load electrically connected together with the battery (30) in parallel to an output terminal of the DC-DC converter (50). [3] The method of claim 1, wherein the first time interval is calculated using an equation: first time interval=T×(Pchg−2Pdiff−Pload) / (Pchg−Pdiff−Pload), where T is the estimated destination arrival time, P chg indicates the charging power, P diff indicates the discharge power and P load which indicates the load. [4] The method of claim 3, wherein the second time interval is calculated using an equation: second time interval = T × (Pdiff) / (Pchg − Pdiff − Pload) where T is the estimated destination arrival time, P chg indicates a charging power, P diff indicates a discharge power and P load indicates a load. [5] System consisting of: a battery; a DC-DC converter (50) configured to convert a voltage level to charge the battery (30); a switch (70) connected between the DC-DC converter (50) and the battery (30); a navigation device (90) configured to receive a destination from a user-estimated destination arrival time; and a control unit (100) designed to: turning on the switch (70) to charge the battery (30) when a vehicle is turned on; if a state of charge (SOC) of the battery (30) is greater than a preconfigured value, turning off the switch (70) for a first time interval calculated on the basis of an estimated destination arrival time transmitted by the navigation device (90); and to switch the switch (70) back on at a time when the first time interval has elapsed in order to charge the battery (30) for a second time interval, wherein the estimated destination arrival time is a time period from a time of turning off the switch (70) to a time of arrival, wherein the first time interval is determined based on the estimated destination arrival time, a charging power, a discharging power, and a load. [6] The system of claim 5, further comprising an electrical load (110) electrically connected together with the battery (30) in parallel to an output terminal of the DC-DC converter (50), wherein the control unit (100) is configured to turn off the switch (70) for the first time interval and adjust the output voltage of the DC-DC converter (50) when an SOC of the battery (30) becomes greater than the preconfigured value, the output voltage being adjusted according to the size of the electrical load. [7] The system of claim 6, wherein the first time interval is calculated using an equation: first time interval=T×(Pchg−2Pdiff−Pload) / (Pchg−Pdiff−Pload), where T is the estimated destination arrival time, P chg indicates the charging power, P diff indicates the discharge power and P load which indicates the load. [8] The system of claim 6, wherein the second time interval is calculated using an equation: second time interval = T × (Pdiff) / (Pchg − Pdiff − Pload) where T is the estimated destination arrival time, P chg indicates a charging power, P diff indicates a discharge power and P load indicates a load. [9] Control unit (100) for an electric or hybrid vehicle, the control unit (100) comprising: a processor; and a memory coupled to the processor, the memory storing a program to be executed by the processor, the program comprising instructions for: Receiving target information; Turning on a switch (70) for charging a battery (30) when starting the vehicle; Switching off the switch (70) for a first time interval when a state of charge (SOC) of the battery (30) is greater than a preconfigured value, wherein the first time interval is derived based on an estimated target arrival time derived from the target information; and switching the switch (70) back on at a time when the first time interval has elapsed, wherein the switch (70) is switched on again to charge the battery (30) for a second time interval, wherein the estimated destination arrival time is a time period from a time of turning off the switch (70) to a time of arrival, wherein the first time interval is determined based on the estimated destination arrival time, a charging power, a discharging power, and a load. [10] The control unit (100) according to claim 9, wherein turning off the switch (70) comprises the steps of turning off the switch (70) and adjusting the output voltage of a DC-DC converter (50) according to the size of an electrical load electrically connected together with the battery (30) in parallel to an output terminal of the DC-DC converter (50). [11] The control unit (100) of claim 9, wherein turning off the switch (70) comprises deriving the first time interval using an equation: first time interval=T×(Pchg−2Pdiff−Pload) / (Pchg−Pdiff−Pload), where T is the estimated destination arrival time, P chg indicates the charging power, P diff indicates the discharge power and P load which indicates the load. [12] The control unit (100) of claim 11, wherein turning off the switch (70) comprises deriving the second time interval using an equation: second time interval = T × (Pdiff) / (Pchg − Pdiff − Pload) where T is the estimated destination arrival time, P chg indicates a charging power, P diff indicates a discharge power and P load indicates a load. [13] Vehicle comprising: the control unit (100) of claim 9; the battery; the switch (70); a DC-DC converter (50) configured to convert a voltage level for charging the battery (30), wherein the switch (70) is connected between the DC-DC converter (50) and the battery (30); and a navigation device (90) configured to receive a destination from a user and forward the destination information to the control unit (100), wherein the vehicle comprises a hybrid vehicle or an electric vehicle. [14] The vehicle of claim 13, further comprising an electrical load (110) electrically connected together with the battery (30) in parallel to an output terminal of the DC-DC converter (50), wherein the control unit (100) is configured to turn off the switch (70) for the first time interval and adjust the output voltage of the DC-DC converter (50) when an SOC of the battery (30) becomes greater than the preconfigured value, the output voltage being adjusted according to the size of the electrical load. [15] A vehicle according to claim 14, wherein the first time interval is calculated using an equation: first time interval = T × (Pchg − 2 Pdiff − Pload ) / (Pchg − Pdiff − Pload ) and where the second time interval is calculated using an equation: second time interval=T×(Pdiff) / (Pchg−Pdiff−Pload), where T is the estimated destination arrival time interval, P chg a charging power, P diffa discharge power and P load indicates a load.

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