Charger device and charging method using the same

Abstract

The charger device described herein is configured to operate in two different user-selectable modes, including a power mode and an economy mode, using a mode selection switch. In addition, a user-adjustable time selection knob is provided in the charger device (10) to enable the user to select operation of the charger device in the economy mode or the power mode. Operation of the charger device in the economy mode includes economy charging or power charging based on the AC line input voltage and a duration selected using the user-adjustable time selection knob until the battery threshold voltage is reached, followed by constant voltage charging until the charging current reached is less than the set threshold current value. Charging in the economy mode facilitates efficient battery charging at a low cost while ensuring that the battery is charged to 100% SOC within a user-selected time interval.

Description

Technical Field

[0001] The subject matter described herein generally relates to a method and apparatus for battery charging, and more particularly to a charger for charging batteries of electric vehicles. Background Art

[0002] One or more batteries are commonly used in vehicles, including hybrid vehicles and electric vehicles, to power the vehicle and various devices used in the vehicle. Typically, such vehicles are equipped with at least one rechargeable battery. A charger device is used to charge the at least one battery. Conventional chargers for charging the at least one battery operate in CC-CV (constant current-constant voltage) mode. In other words, the charger provides a constant current output for charging the battery to 80%-90% of its capacity, while the charger provides a constant voltage output for charging the battery to the remaining capacity of the battery, thereby charging the battery to 100%. Conventional chargers operate as described above to perform a 100% charge, generally without regard to alternating current (AC) line voltage variations. However, charging during periods of low AC line voltage causes the charger to draw a higher input current, thereby affecting the charger's efficiency and also resulting in higher electricity consumption costs for the consumer.

[0003] A known technique describes a method for charging a battery, wherein the method involves determining the voltage on an AC power line via a battery charger. The method determines whether the AC line voltage falls within a predetermined voltage range in order to adjust the output current to the battery accordingly. Thus, the output current is allowed to vary based on the AC line voltage until the battery's actual state of charge reaches a target state of charge. Thus, charging the battery is performed by continuously monitoring the AC line voltage, and charging continues until the battery's target state of charge is reached. Because charging is performed by continuously monitoring the AC line voltage, the likelihood of the battery being rapidly charged remains low. Consequently, it may not be possible to quickly charge the battery to its full capacity while continuously monitoring the AC line voltage.

[0004] Therefore, there is a need for a charger device that can overcome the above-mentioned and other shortcomings of conventional charger devices while maintaining high operating efficiency of the charger device. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The detailed description of the subject matter is described with reference to the accompanying drawings. The same reference numerals are used throughout the drawings to refer to similar features and components.

[0006] Figure 1 A charger device for a battery according to an embodiment of the present invention is shown.

[0007] Figure 2 A flow chart depicting the steps of a method of operation of the charger device selected to operate in a power mode is shown.

[0008] Figure 3 A flow chart depicting the steps of a method of operation of the charger device selected to operate in economy mode is shown.

[0009] Figure 4a A graph of the RMS voltage available for charging versus time in economy mode is shown.

[0010] Figure 4b A graph of charging current available for charging in economy mode versus time is shown.

[0011] Figure 4c A graph of % SOC available for charging versus time in economy mode is shown. DETAILED DESCRIPTION

[0012] The present invention has been accomplished in view of the above circumstances.

[0013] An object of the present invention is to provide a charger device for charging a battery of a vehicle, the charger device being configured to operate in two different user-selectable charging modes including a power mode and an economy mode.

[0014] Another object of the present invention is to provide a charger device configured to perform battery charging in one of the two different user-selectable charging modes by identifying AC line input voltage variations.

[0015] Still another object of the present invention is to provide a charger device configured to perform battery charging in the economy mode by recognizing a change in AC line input voltage.

[0016] Another object of the present invention is to provide a charger device having a configuration that allows a user to select a time when charging can be performed in an economy mode.

[0017] Another object of the present invention is to provide a charger device configured to automatically adjust charging in an economy mode by switching between two types of charging, including economy charging and power charging, to ensure that the battery is fully charged within a user-selected time interval.

[0018] Yet another object of the present invention is to provide a charger device capable of performing economical charging in an economical mode based on an identified AC line input voltage variation and based on a user-selected duration.

[0019] Still another object of the present invention is to provide a charger device capable of performing power supply charging in an economic mode by charging a battery at a maximum charging current regardless of a change in an AC line input voltage.

[0020] Yet another object of the present invention is to provide a charger device configured to supply a variable output charging current corresponding to different input voltages recognized by the charger device.

[0021] Yet another object of the present invention is to provide a charger device that is simple and easy to use.

[0022] Yet another object of the present invention is to provide a method for efficiently charging a battery of a vehicle.

[0023] In view of the above-mentioned and other objects, the present invention provides a charger device for charging one or more batteries of a vehicle, including a two-wheeled hybrid vehicle and a two-wheeled electric vehicle. According to one aspect of the present invention, the charger device is configured to perform charging in two different user-selectable charging modes, including an economy mode and a power mode. Specifically, a mode switch is provided in the charger device for selecting either the economy mode or the power mode for charging the battery. More specifically, while the mode switch is turned on (ON), the economy mode is selected for battery charging, while the mode switch is turned off (OFF), the power mode is selected for battery charging. Thus, the user / driver can select either the economy mode or the power mode for charging by turning the mode switch on or off, respectively. In particular, charging in the economy mode includes efficient charging for a user-selected duration, while charging in the power mode includes rapid charging. According to one aspect of the present invention, charging of the battery in the economy mode or the power mode continues until a battery threshold voltage is reached, and then constant voltage charging is performed to complete charging of the battery to 100% SOC (battery state of charge).

[0024] According to another aspect of the present invention, the charger device is provided with a user-adjustable time selection knob for allowing the user / driver to select the duration for which he / she desires to charge the battery in economy mode. Thus, the user-adjustable time selection knob can be used to adjust the duration for which the user / driver desires to charge the battery in economy mode. However, the knob cannot be adjusted to select the duration for which battery charging is to be performed in power mode.

[0025] According to another aspect of the present invention, a charger device is configured to perform two types of charging in the economy mode, including economy charging and mains charging, based on a driver-selected duration and the AC line input voltage. For example, the charger device is configured to automatically adjust charging in the economy mode by switching between economy charging and mains charging to ensure that the battery is fully charged within the user-selected duration. Typically, the charger device is configured to switch from economy charging to mains charging when the difference between the user-selected duration and the elapsed charging time is less than the combined time required for mains charging and constant-voltage charging. Thus, while the battery is efficiently charged to at least some portion of its capacity by supplying an output / charging current corresponding to the input AC line voltage, the maximum charging current for charging the battery to its remaining capacity is supplied by performing mains charging independent of the AC line input voltage, ensuring that the battery is fully charged to 100% capacity within the user-selected duration. Therefore, according to the present invention, the battery can be quickly charged to its full capacity while also monitoring the AC line input voltage in the economy mode, thereby reducing power waste. Consequently, the customer's electricity costs are also reduced.

[0026] Thus, the subject matter described herein relates to a charger apparatus for charging one or more batteries used to power vehicles, including hybrid vehicles and electric vehicles. Specifically, the charger apparatus is capable of efficiently charging the one or more batteries while taking into account the AC line input voltage available for charging. The charger apparatus is also capable of enabling time-limited rapid battery charging while monitoring the AC line input voltage.

[0027] An exemplary embodiment of a charger device according to the present invention will be described in detail below. The embodiments described herein are applicable to vehicles powered by two or more power sources, including an internal combustion engine, a traction motor, and one or more batteries. However, the present invention is not limited in its application and may also be applied to vehicles employing only a traction motor and batteries, such as electric vehicles.

[0028] Figure 1 A charger device (10) according to an embodiment of the present invention is shown. According to one aspect of the present invention and as can be Figure 1As seen in FIG, the charger device (10) includes at least two switches (11), a user-selectable time knob (12), and an AC input plug (13). According to an embodiment, the at least two switches (11) include a power supply (11a) and a mode selection switch (11b). While the power switch (11a) is used to turn the charger device (10) on or off, the mode selection switch (11b) is used to select different charging modes. For example, according to one aspect of the present invention, two charging modes including a power mode and an economy mode are made available in the charger device for selection by a user / driver. While charging in the power mode allows for fast charging regardless of the AC input voltage, charging in the economy mode allows for optimal charging taking into account the AC input voltage. According to one aspect, the charger device (10) is configured to perform battery charging in the economy mode when the mode selection switch (11b) is selected / turned on. Thus, based on the user's preference, a mode for battery charging can be selected. In addition, based on his / her preference, the user can also select the time for performing charging in the economy mode by adjusting the user-selectable time knob (12). Thus, based on the time selected by the user, the charging of the one or more batteries to 100% SOC (10) is completed by the charger device (10). According to one aspect of the present invention, the user-selectable time knob (12) can be adjusted only when the mode selection switch (11b) is turned on. In other words, the user-selectable time knob (12) is adjustable only when the user / driver selects the economy mode for battery charging by turning on the mode selection switch (11b). Therefore, if the user / driver believes that sufficient time is available for charging, he / she can select the economy mode for charging. In the event that the time available for charging is shorter, the power mode can be selected by keeping the mode selection switch (11b) in the off condition. In addition, regardless of the charging mode in the power mode or the economy mode, the charger device (10) generally initially performs constant current charging until the battery voltage reaches a predetermined battery voltage threshold, and then performs constant voltage charging until the battery current / battery charging current reaches / arrives a predetermined battery current threshold, and then the charger device stops charging. For example, for a 10AH battery having 13 cells connected in series, with a maximum battery voltage of 4.1V for each cell, the charger device performs constant current charging until the battery voltage reaches a predetermined battery voltage threshold of 53.3V, and then performs constant voltage charging until the battery current / battery charging current reaches / arrives a predetermined battery current threshold of 0.3A, in which case the charger device stops charging.

[0029] Figure 2A flow chart depicting the steps of a method for operating the charger device for charging the one or more batteries in power mode is shown. According to one aspect of the present invention, the charger device (10) includes a controller installed therein for controlling the operation of the device in the power mode and the economy mode. Specifically, Figure 2 The steps involved in the operation of the charger device (10) in the power mode are shown.

[0030] In the first step of its operation at block 200, the controller determines whether the power switch is on / off. Under the condition that the power switch (11a) is in the on state, at block (201), the controller determines whether the mode selection switch 11b is in the on state or in the off state. Under the condition that the mode selection switch is in the off state, at block (202), the controller causes the charger device to operate in the power mode. Battery charging in the power mode includes constant current charging. Therefore, at block (203), the controller causes the charger device 10 to perform constant current charging. In addition, at block (204), the controller continuously monitors the battery voltage and determines whether the battery voltage has reached a predetermined voltage threshold stored therein, the predetermined voltage threshold corresponding to the voltage threshold for constant current battery charging. Under the condition that the battery voltage has reached the predetermined voltage threshold, at block (205), the controller causes the charger device to perform constant voltage charging. During constant voltage charging, the controller monitors the battery charging current / battery current. Under the condition that the battery charging current is less than a predetermined battery charging current threshold, at block (206), the controller causes the charger device (10) to stop charging. Under the condition that the battery charging current is not less than the predetermined battery charging current threshold, the controller causes the charger device to continue constant voltage charging. Thus, the charger device (10) completes battery charging to 100% SOC by performing constant voltage charging after constant current charging.

[0031] Figure 3 The operation of the charger device in the economy mode is shown in FIG. Figure 3 A flow chart depicting the steps of a method of operating the charger device for charging the one or more batteries in the economy mode is shown. Under the condition that the mode select switch is in the on state selected by the user / driver and detected by the controller, the controller causes the charger device (10) to operate in the economy mode, as depicted in box (301). In addition, the controller checks the position of the user-selectable time knob (12) on the charger device (10). For example, as can be Figure 1As seen in FIG, the knob (12) is configured to be positioned at five different positions corresponding to different charging time intervals (e.g., 4 hours, 6 hours, 8 hours, 10 hours, and 12 hours). Based on the position of the user-selectable time button (12), the controller determines the time at which the charger device should perform charging in economy mode and then perform constant voltage charging. Therefore, at box (302), the controller checks the position of the knob (12) and selects the total time available for charging in economy mode by leaving a minimum of 30 minutes for constant voltage charging from the time selected by the user using the knob (12). In addition, at box (303), the controller checks whether the battery voltage is less than or greater than the predetermined voltage threshold corresponding to the voltage threshold for constant current battery charging. If the battery voltage is less than the predetermined voltage threshold, at box (304), the controller begins monitoring the AC line input voltage received by the charger device for a predetermined time interval and selects a charging current corresponding to the AC line input voltage. Therefore, at block (305), the controller operates the charger device by charging the one or more batteries with a charging current corresponding to the AC line input voltage. In other words, the charger device performs economy charging in the economy mode. While the charger device is performing economy charging, the controller continuously monitors the remaining time available to complete charging in the economy mode based on a user-selected time for charging in the economy mode. In addition, the memory, to which information regarding the estimated time required for power supply charging is fed, is configured to enable power supply charging within a predetermined duration.

[0032] At block (306), the controller checks whether the remaining time is less than the estimated time required for power source charging. Under the condition that the remaining time for economical charging is less than the estimated time required for power source charging, at block (307), the charger device performs constant current charging using a rated current regardless of the AC line input voltage. Furthermore, while performing constant current charging, at block (308), the charger device checks whether the battery voltage is less than the predetermined voltage threshold corresponding to the voltage threshold for constant current battery charging. If the battery voltage is less than the predetermined voltage threshold, the charger device continues constant current charging, but if the battery voltage is greater than the predetermined voltage threshold, at block 310, the controller causes the charger device to perform constant voltage charging. Furthermore, the charger device continues constant voltage charging until the battery charging current value is less than the predetermined threshold current value stored in the controller.

[0033] Under the condition that the remaining time for economical charging is not less than the estimated time required for power charging, at block (309), the controller checks whether the battery voltage at that moment is less than the predetermined voltage threshold. If the battery voltage is less than the predetermined voltage threshold corresponding to the voltage threshold for constant current battery charging, the controller causes the charger device to continue constant current charging by taking into account the AC line input voltage. However, if the battery voltage is greater than the predetermined voltage threshold, the controller causes the charger device to perform constant voltage charging at block (310) to complete charging the battery to 100% SOC and continue constant voltage charging until the battery charging current value is less than the predetermined threshold current value stored in the controller.

[0034] Therefore, according to one aspect of the present invention, the charger device is configured to perform charging regardless of the AC line input voltage even in economy mode. This is to ensure that charging of the one or more batteries is completed within the total time selected by the user for economy charging.

[0035] With the help of Figures 4a to 4c An example for explaining the operation of the charger device in the economy mode is explained below. For example, if the user has turned on the mode switch (11b) and has selected a time interval of 6 hours for charging in the economy mode using the knob (12), the controller records 6 hours or 360 minutes as the total charging time. However, according to an embodiment of the present invention, the controller recalculates the available time for economy mode charging by subtracting 30 minutes from the time taken for constant voltage charging. Therefore, as in Figure 4a As can be seen, the total time available for charging in economy mode is set to 330 minutes. Under the condition that the battery SOC is low at the beginning, the controller causes the charger device to perform constant current charging. Specifically, the charger device performs constant current charging based on the AC line input voltage. In other words, the charger device performs constant current charging with a charging current corresponding to the AC line input voltage. As shown in Figure 4b As can be seen in FIG and according to this example, the AC line input voltage detected by the controller is 180V (see Figure 4a ), and therefore the selected constant current magnitude is 2 amps. The controller will continue to monitor the AC line input voltage and maintain the magnitude of the constant current until the remaining time available for economy charging is greater than the estimated time required for mains charging or charging at the maximum magnitude constant current. For example, at time t = 190 minutes, the remaining time available for charging in economy mode will be 330-190 = 140 minutes, which is less than the estimated time of 140.4 minutes required for mains charging / charging at the maximum magnitude constant current; as in Figure 4bAs can be seen in FIG, the current will change from 2 amps to 5 amps. In other words, the estimated time is only the time required to charge the battery with a certain percentage of battery SOC at the highest level of current. In addition, the charger device will continue to charge the one or more batteries at a constant current of the maximum level / highest rated current regardless of the AC input voltage until the battery voltage reaches the predetermined voltage threshold. The charger device continues to charge at the highest level of constant current until the battery SOC reaches 95% (e.g., Figure 4c ), and then constant voltage charging was performed from 330 minutes to 360 minutes to reach 100% battery SOC.

[0036] Therefore, as is apparent from the above teachings, when the remaining time available for charging in economy mode is less than the estimated time required to charge the power source, charging is ensured to be completed within the user-selected time in economy mode by switching to constant current charging at the highest level. Thus, while ensuring rapid charging within the user-selected time interval, a balance is achieved by monitoring the AC line input voltage to ensure economical charging.

Claims

1. A charger device (10) configured for charging one or more batteries of a vehicle, the charger device (10) being configured to operate in two different user-selectable modes, in, The charger device (10) is operable in one of the two different user-selectable modes at user-selectable time intervals; wherein the two different user-selectable modes include a power mode and an economy mode, wherein the charger device (10) is operable in both the power mode and the economy mode until a battery threshold voltage is reached, wherein when the battery threshold voltage is reached, the charger device (10) performs constant voltage charging on the one or more batteries until a charging current is reached, the charging current being less than a set threshold current value; The charger device (10) is configured to perform one of economy charging and power charging based on an AC line input voltage and a user-selected duration when the charger device (10) operates in the economy mode until the battery threshold voltage is reached.

2. The charger device (10) according to claim 1, wherein the charger device (10) comprises: at least two switches (11) and a user-adjustable time selection knob (12), The at least two switches include a power switch (11a) and a mode selection switch (11b); and an on condition of the mode selection switch (11b) allows charging of the one or more batteries in the economy mode.

3. The charger device (10) of claim 2, wherein the charger device (10) is configured to perform one of economy charging and mains charging based on an AC line input voltage and a duration selected using the user-adjustable time selection knob (12) until a battery threshold voltage is reached when the charger device (10) is operated in the economy mode, in, When the battery threshold voltage is reached, the charger device (10) performs the constant voltage charging on the one or more batteries until the charging current reached is less than a set threshold current value.

4. The charger device (10) of claim 3, wherein the economical charging comprises charging the one or more batteries with a charging current corresponding to the AC line input voltage.

5. The charger device (10) of claim 3, wherein the power supply charging comprises charging the one or more batteries at a maximum charging current that is independent of the AC line input voltage.

6. A charger device (10) according to claim 3, wherein the charger device (10) is configured to perform economy charging of one or more batteries based on the AC line input voltage until the difference between the duration selected using the user-adjustable time selection knob (12) and the elapsed charging time is greater than the combined time required to perform the mains charging and the constant voltage charging; and then switch to the mains charging in the economy mode.

7. A charger device (10) according to claim 3 or claim 6, wherein a maximum charging current for charging the one or more batteries to their remaining capacity is provided by the charger device (10), wherein the charger device (10) is configured to perform the power charging independently of the AC line input voltage so as to ensure that the charging of the one or more batteries to 100% capacity is completed within the duration selected using the user-adjustable time selection knob (12).

8. The charger device (10) according to claim 1, wherein When the charging current is less than the set threshold current value, charging of the one or more batteries is interrupted.

9. The charger device (10) according to claim 1, wherein: Charging the one or more batteries in the power mode includes charging at a maximum charging current independent of the AC input voltage until the one or more batteries reach the threshold voltage, When the one or more batteries reach the threshold voltage, the charger device (10) performs the constant voltage charging of the one or more batteries until the charging current reached is less than the set threshold current value.

10. A method for charging one or more batteries of a vehicle using a charger device (10), the method comprising the steps of: The charger device (10) determines one of an on condition and a off condition of a mode selection switch (11b); determining, by the charger device (10), a duration selected by a user via the user-adjustable time selection knob (12); By the charger device (10), when the mode selection switch (11b) is in an on condition, charging of the one or more batteries is performed in at least one of an economy mode and a power mode; The charger device (10) performs the charging in the economic mode by monitoring the AC line input voltage and selecting a charging current corresponding to the AC line input voltage; continuing said charging by said charger device (10) in said economy mode until the difference between said selected duration selected using said user adjustable time selection knob (12) and the elapsed charging time is greater than the combined time required for mains charging of said one or more batteries and constant voltage charging of said one or more batteries; charging the one or more batteries by the charger device (10) at a maximum charging current that is independent of the AC line input voltage if the difference between the duration selected using the user-adjustable time selection knob (12) and the elapsed charging time is less than the combined time required for the power supply charging and the constant voltage charging; When the battery voltage is greater than or equal to the battery threshold voltage, the charger device (10) charges the one or more batteries at the constant voltage; When the battery charging current is less than a set threshold current value, the charger device (10) interrupts the battery charging.

11. The method according to claim 10, comprising: When the mode selection switch (11b) is in the off condition, the charger device (10) charges the one or more batteries in the power mode at a maximum charging current that is independent of the AC line input voltage.

12. The method according to claim 11, comprising: The charging of the one or more batteries by the charger device (10) in the power supply mode includes charging at a maximum charging current independent of the AC input voltage until the battery reaches the threshold voltage, and then performing constant voltage charging until the charging current reached is less than the set threshold current value.

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