Charging system and charger for reducing inrush current

Abstract

A charging system and a charger are provided. The charging system includes: a battery pack including at least one battery cell and a battery management module; and a charger including a connector configured to detect a connection with the battery pack, a communicator configured to communicate with the battery management module, and a controller configured to control charging of the battery pack. The controller of the charger is configured to output a wake-up voltage when a connection with the battery pack is detected through the connector, receive a battery voltage value from the battery management module through the communicator, determine a charge start voltage based on the battery voltage value, and start charging the battery pack after outputting the charge start voltage.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on and claims the benefit of priority from Korean Patent Application No. 10-2020-0113197 filed in the Korean Intellectual Property Office on September 4, 2020, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Embodiments relate to a charging system and a charger for reducing inrush current. Background Art

[0004] When the difference between the voltage of the charger and the voltage of the battery is large, a surge current is generated. Summary of the invention

[0005] An embodiment is directed to a charging system, the charging system including a battery pack and a charger, the battery pack including at least one battery cell and a battery management module, the charger including a connector configured to detect a connection with the battery pack, a communicator configured to communicate with the battery management module, and a controller configured to control charging of the battery pack. The controller of the charger is configured to output a wake-up voltage when a connection with the battery pack is detected through the connector, receive a battery voltage value from the battery management module through the communicator, determine a charge start voltage based on the battery voltage value, and start charging the battery pack after outputting the charge start voltage.

[0006] The controller of the charger may be configured to output a charging current having a preset magnitude to at least one battery cell and output a charging voltage having a preset magnitude to the battery pack when the battery pack starts to be charged.

[0007] The controller of the charger may be configured to determine the charge start voltage to be greater than the battery voltage value by a preset margin value.

[0008] The margin value may be preset based on a line resistance value of at least one battery cell and a preset charging current value.

[0009] The battery management module may be deactivated when at least one battery cell does not supply power to a load and does not receive power from a charger within a preset period of time, and may be activated when a wake-up voltage is received.

[0010] The battery management module may be configured to detect connection with the charger by receiving a signal transmitted from the communicator of the charger.

[0011] The battery pack may further include a switch configured to forcibly activate the battery management module.

[0012] When a charge stop condition is detected, the battery management module may be configured to send a charge stop signal requesting output stop to a controller of the charger.

[0013] The controller of the charger may be configured to stop charging the battery pack when a charge stop signal is received, and when release of the connection with the battery pack is detected and then connection with another battery pack is detected again, the controller of the charger may be configured to output voltage or current to the battery pack or another battery pack.

[0014] The controller of the charger may be configured not to charge the battery pack even if the battery pack is connected until it is detected that the connection with the battery pack is released after receiving the charge stop signal.

[0015] When the battery voltage value is less than the wake-up voltage, the controller of the charger may be configured not to start charging the battery pack.

[0016] According to another aspect of the present disclosure, a charger includes a connector configured to detect a connection to a battery pack including at least one battery cell, a communicator configured to communicate with a battery management module of the battery pack, and a controller configured to control charging of the battery pack, wherein the controller is configured to output a wake-up voltage when a connection to the battery pack is detected through the connector, receive a battery voltage value from the battery management module through the communicator, determine a charging start voltage based on the battery voltage value, and output the charging start voltage and start charging the battery pack.

[0017] The controller may be configured to output a charging current having a preset magnitude to at least one battery cell and output a charging voltage having a preset magnitude to the battery pack when the battery pack starts to be charged.

[0018] The controller may be configured to determine the charge start voltage to be greater than the battery voltage value by a preset margin value.

[0019] The margin value may be preset based on a line resistance value of at least one battery cell and a preset charging current value.

[0020] The controller may be configured to send a signal to the battery management module via the communicator to allow the battery management module to detect connection with the charger.

[0021] The controller can be configured to stop charging the battery pack when a charge stop signal is received from the battery management module through the communicator, and output voltage or current to the battery pack or another battery pack when release of the connection with the battery pack is detected and then connection with the battery pack or another battery pack is detected again.

[0022] The controller may be configured not to charge the battery pack even if the battery pack is connected until a release of the connection with the battery pack is detected after receiving a charge stop signal from the battery management module through the communicator.

[0023] When the battery voltage value is less than the wake-up voltage, the controller may be configured to not start charging the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Features will become apparent to those skilled in the art by describing in detail example embodiments with reference to the accompanying drawings, in which:

[0025] Figure 1 shows an example of the structure of a charging system according to an example embodiment;

[0026] Figure 2 is a circuit diagram of a battery pack 10 of a charging system 100 according to an example embodiment;

[0027] Figure 3 shows an example of a signal flow between the battery management module 11 of the battery pack 10 and the controller 23 of the charger 20 according to an example embodiment;

[0028] Figure 4 is an example graph of output voltage and output current of the charger 20 according to an example embodiment;

[0029] Figure 5 shows an operation example of the controller 23 of the charger 20 according to an example embodiment; and

[0030] Figure 6 Example graphs G1 and G2 of the output voltage of the charger 20 according to various example embodiments are shown. DETAILED DESCRIPTION

[0031] Example embodiments will now be described more fully below with reference to the accompanying drawings; however, they may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to make this disclosure thorough and complete and will fully convey example implementations to those skilled in the art. In the accompanying drawings, the dimensions of layers and regions may be exaggerated for clarity of illustration. The same reference numerals refer to the same elements throughout.

[0032] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. When an expression such as "at least one of" is used before a list of elements, it modifies the entire list of elements and does not modify the individual elements of the list.

[0033] It should be understood that although the terms "first", "second", etc. can be used to describe various components, these components should not be limited by these terms. These components are only used to distinguish one component from another component.

[0034] As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0035] It will be further understood that the terms “include” and / or “comprises” used herein specify the presence of stated features or components, but do not preclude the presence or addition of one or more other features or components.

[0036] It should be understood that when a region, component, unit, block or module is referred to as being connected to another region, component, unit, block or module, it can be directly or indirectly connected to the other region, component, unit, block or module. That is, for example, there can be intermediate regions, components, units, blocks or modules.

[0037] For the sake of brevity, existing electronic devices, control systems, software, and other functional aspects of the systems may not be described in detail. In addition, the connecting lines or connectors shown in the various figures are intended to represent example functional relationships and / or physical or logical couplings between the various elements. It should be noted that many alternative or additional functional relationships, physical connections, or logical connections may exist in an actual device. In addition, no item or component is essential unless the element is specifically described as "essential" or "critical"

[0038] In addition, unless otherwise specified herein, the description of numerical ranges herein is intended only to be used as a shorthand method for individually referring to each individual numerical value falling within the range, and each individual numerical value is incorporated into the specification as if it were individually narrated herein. In addition, the steps of all methods described herein can be performed in any suitable order, unless otherwise specified herein or clearly contradictory to the context. Embodiments are not limited to the described order of steps. The use of any and all examples or exemplary language (e.g., "such as") provided herein is only to better illustrate the embodiments, rather than to limit the scope of the embodiments, unless otherwise stated.

[0039] Figure 1 An example of a structure of a charging system 100 according to an example embodiment is shown. Figure 2 is a circuit diagram of a battery pack 10 of a charging system 100 according to an example embodiment.

[0040] refer to Figure 1 and Figure 2, the charging system 100 may include a battery pack 10 and a charger 20. The battery pack 10 may include a battery management module 11, at least one battery cell 12, and a protection circuit 13. The battery management module 11 may detect the state (e.g., voltage, current, temperature) of the battery cell 12, calculate the charging state or charging capacity, and detect an abnormal state.

[0041] The charger 20 may include a connector 21 , a communicator 22 that performs a communication function, and a controller 23 that controls an output voltage and performs an output block function.

[0042] In various example embodiments, the battery pack 10 and the charger 20 may further include other components.

[0043] The battery pack 10 can be connected to the charger 20 through the connector 17, and a charging operation of at least one battery cell 12 can be performed. In addition, the battery pack 10 can be connected to an external load (not shown) through the connector 17, and a discharging operation of the battery cell 12 can be performed. The high current path between the battery cell 12 and the connector 17 can be used as a charging / discharging path. The power supply terminal of the charger 20 or the external load (not shown) can be connected to the first group of terminals P+ and the second group of terminals P- of the connector 17.

[0044] According to example embodiments, the battery pack 10 and the charger 20 may include a signal line through which power and communication signals are exchanged between the battery pack 10 and the charger 20. For example, a communicator 22 (eg, a communication terminal) of the charger 20 may be connected to a communication terminal DATA of the connector 17.

[0045] The battery unit 12 may include one or more batteries B1 to B4 and may be charged or discharged at a specific voltage. Figure 2 B+ and B- respectively represent the positive terminal B+ and the negative terminal B- of the battery cells B1 to B4 connected in series. The number of the battery cells 12 may vary according to the specifications of the external load.

[0046] The protection circuit 13 of the battery pack 10 may include a charging device 14 and a discharging device 15 .

[0047] The battery management module 11 can detect the voltage of the battery cell 12 and control the operation of the charging device 14 and the discharging device 15, thereby controlling the charging / discharging of the battery cell 12. For example, when the battery pack 10 and the charger 20 are connected to each other through the connector 17, the battery management module 11 can set the charging device 14 to be turned on and the discharging device 15 to be turned off, thereby allowing the battery cell 12 to be recharged. In addition, when the battery pack 10 and an external system (not shown) are connected to each other through the connector 17, the battery management module 11 can set the charging device 14 to be turned off and the discharging device 15 to be turned on, thereby allowing the battery cell 12 to be discharged. The battery management module 11 can detect the voltage of each battery cell B1 to B4.

[0048] The charging device 14 and the discharging device 15 can be connected to the high current path between the battery cell 12 and the connector 17, and can charge or discharge the battery cell 12. The charging device 14 may include a field effect transistor (hereinafter referred to as FET1) and a parasitic diode (hereinafter referred to as D1). The discharging device 15 may include a field effect transistor (hereinafter referred to as FET2) and a parasitic diode (hereinafter referred to as D2). The connection direction between the source and the drain of FET1 may be opposite to that of FET2. FET1 having the above configuration may limit the current from the connector 17 to the battery cell 12. FET2 may limit the current from the battery cell 12 to the connector 17. D1 and D2 may be configured to allow current to flow in a direction opposite to the direction of limiting the current.

[0049] The connector 17 may be connected to at least one battery cell 12, and may be connected to the charger 20 when the battery cell 12 is charged, thereby serving as a terminal for charging the battery cell 12. When the battery cell 12 is discharged, the connector 17 may be connected to an external load (not shown), and may serve as a terminal for discharging the battery cell 12. The connector 17 may include a first set of terminals P+ and a second set of terminals P-. The first set of terminals P+ may be a positive battery terminal connected to the positive terminal B+ of the battery cell 12. The second set of terminals P- may be a negative battery terminal connected to the negative terminal B- of the battery cell 12. When the charger 20 is connected to the connector 17, the battery cell 12 may be charged by the charger 20, and when the external load is connected to the connector 17, the battery cell 12 may be discharged by the external load.

[0050] In an example embodiment, the connector 17 may include a communication terminal DATA connected to the battery management module 11. In an example embodiment, when the charger 20 is connected to the connector 17, the communication terminal DATA may enable communication between the battery management module 11 and the charger 20 (e.g., the communicator 22). For example, the communication terminal DATA may transmit voltage information of the battery cell 12, charging control information, etc., from the battery management module 11 to the charger 20. For example, the communication terminal DATA may transmit an alarm signal output from the battery management module 11, etc., to an external system (not shown).

[0051] The sensor resistor 16 may be connected to a high current path between the battery cell 12 and the connector 17. In detail, for example, the sensor resistor 16 may be connected between the negative terminal B- and the second group terminal P- of the battery cell 12. In addition, the sensor resistor 16 may be connected to the battery management module 11. Therefore, the sensor resistor 16 may allow the battery management module 11 to identify the voltage value across the sensor resistor 16 and the resistance value of the sensor resistor 16, and identify the charge / discharge current. Therefore, the sensor resistor 16 may send information about the charge current or discharge current of the battery cell 12 to the battery management module 11.

[0052] According to an example embodiment, the controller 23 of the charger 20 may detect connection with the connector 17 through the connector 21. The connector 21 may include, for example, a connection terminal.

[0053] When the connection with the battery pack 10 is detected through the connector 21, the controller 23 may send a specific communication signal to the battery pack 10 (e.g., the battery management module 11), and may detect the connection between the battery pack 10 (e.g., the battery management module 11) and the charger 20. For example, when the charger 20 is connected to the battery pack 10, the controller 23 may send a specific communication signal through the communicator 22 in a specific cycle.

[0054] The controller 23 may control the output voltage of the charger 20. When a connection with the battery pack 10 is detected through the connector 21, the controller 23 may output a wake-up voltage at which the battery management module 11 is activated.

[0055] The controller 23 may receive a communication signal from the battery management module 11 through the communicator 22. According to an example embodiment, the controller 23 may receive a signal indicating a battery voltage value and a signal indicating whether the battery pack 10 is rechargeable from the battery management module 11 through the communicator 22. The battery voltage value may indicate a voltage value of at least one battery cell 12. The battery voltage value may indicate, for example, a voltage value between a positive terminal B+ and a negative terminal B- of battery cells B1 to B4 connected in series.

[0056] The controller 23 may check the signal received through the communicator 22 (e.g., a signal indicating the battery voltage value and whether the battery pack 10 is rechargeable), and may output a charge start voltage when the battery cell 12 needs to be recharged. The charge start voltage may be determined by the controller 23 according to the battery voltage value. The charge start voltage may be, for example, greater than the wake-up voltage and less than a preset full charge voltage. The charge start voltage may be higher than the battery voltage value by a margin value. The margin value may be, for example, preset.

[0057] Then, the battery management module 11 switches the charging device 14 to the on state so that the charging current can start to flow. When the charging current starts to flow, the controller 23 of the charger 20 can output a preset charging current to the battery cell 12. Then, the controller 23 can output a preset charging voltage (e.g., a full charging voltage) to the battery pack 10.

[0058] The controller 23 may detect that charging (of the battery pack 10 ) is blocked through the communicator 22 , or when receiving a charging stop signal from the battery management module 11 , the controller 23 may stop outputting current and / or voltage.

[0059] For example, when the battery management module 11 detects a charge stop condition, the battery management module 11 may send an output stop signal (via the communicator 22) to the controller 23 requesting output stop. For example, when the battery management module 11 detects that the battery pack 10 is fully charged, the charge stop signal may be sent to the controller 23. The controller 23 of the charger 20 may stop charging the battery pack 10 in response to the charge stop signal.

[0060] Once charging is stopped, even if the battery pack 10 is connected to the charger 20, the controller 23 may not charge the battery pack 10 until the release of the connection with the battery pack 10 is detected through the connector 21. In other words, after receiving the charge stop signal, the controller 23 may not charge the battery pack 10 until the release of the connection with the battery pack 10 is detected.

[0061] When connection with the battery pack 10 or another battery pack is detected again through the connector 21 after the release of the connection with the battery pack 10 is detected through the connector 21 , the controller 23 may output a voltage or a current to the connected battery pack.

[0062] The battery pack 10 may include a switch for forcibly activating the battery management module 11. For example, the switch may be used to activate or shut down the operation of the battery management module 11.

[0063] According to an example embodiment, when the battery pack 10 is not discharged and is not charged, the battery management module 11 may be deactivated to protect the charging capacity. For example, when the battery unit 12 does not supply power to the load within a preset period of time and does not supply power from the charger 20, the battery management module 11 may be deactivated. When a wake-up voltage is received, the battery management module 11 may be activated.

[0064] The battery management module 11 may detect the connection with the charger 20 by receiving a signal from the communicator 22 of the charger 20. For example, the battery management module 11 may detect the connection with the charger 20 in response to a specific signal transmitted from the communicator 22 of the charger 20.

[0065] Figure 3 An example of a signal flow between the battery management module 11 of the battery pack 10 and the controller 23 of the charger 20 according to an example embodiment is shown. Figure 4 is an example curve of the output voltage and output current of the charger 20 according to the example embodiment. Figure 3 and Figure 4 Provide a description.

[0066] In operation S101 , the controller 23 may detect a connection between the charger 20 and the battery pack 10 using the connector 21 .

[0067] In operation S102, in response to detecting the connection with the battery pack 10, the controller 23 may output a wake-up voltage V1 (see Figure 4 For example, the controller 23 may control the circuit to enable the charger 20 to output the wake-up voltage V1.

[0068] In operation S103 , the battery management module 11 may be activated in response to the receipt of the wake-up voltage V1 .

[0069] In operation S104, the activated battery management module 11 may measure the voltage of the battery cell 12. For example, the battery management module 11 may measure a series voltage value between a positive terminal B+ and a negative terminal B- of at least one battery cell.

[0070] In operation S105, the battery management module 11 may send a signal indicating a measured value of the battery voltage to the controller 23 of the charger 20. For example, the battery management module 11 may send data indicating the battery voltage value to the controller 23 through the communication terminal DATA of the connector 17. The controller 23 of the charger 20 may receive the battery voltage value through the communicator 22 (e.g., a communication terminal).

[0071] In operation S106, the controller 23 may determine a charge start voltage V2 based on the battery voltage value. The charge start voltage V2 may be a voltage output when the battery pack 10 starts charging, or a voltage output to start charging the battery pack 10.

[0072] refer to Figure 4 , the charge start voltage V2 may be higher than the battery voltage value Vb by a margin value Vm. The margin value Vm may be preset, for example. The margin value Vm may be preset based on the line resistance value and the preset charging current value. For example, the margin value Vm may be set to a value obtained by multiplying a preset charging current by a line resistance value from the charger 20 to the battery cell 12. The charge start voltage V2 may be higher than the wake-up voltage V1 and lower than the full charge voltage Vc.

[0073] In operation S107, the controller 23 may output the determined charging start voltage V2. Although not shown, the battery management module 11 may allow the charging current to flow by switching the charging device 14 to the on state. For example, when the charging start voltage V2 is received from the charger 20, the battery management module 11 may switch the charging device 14 to the on state, and thus, the charging current may flow due to the switching.

[0074] In operation S108, the controller 23 may output a charging voltage and / or a charging current according to the flow of the charging current, and may start charging the battery pack 10. For example, the controller 23 may start charging the battery pack 10 by outputting a charging start voltage V2. For example, the controller 23 may output a charging voltage or a charging current according to the flow of the charging current.

[0075] According to an example embodiment, the controller 23 may output a charging current Ic having a preset magnitude to the battery cell 12. Then, the controller 23 may output a preset charging voltage Vc to the battery pack 10.

[0076] refer to Figure 4 14 , when it is detected that the battery is fully charged, the battery management module 11 can switch the charging device 14 to a disconnected state.

[0077] In addition, although not shown, when a charge stop condition is detected, the battery management module 11 may send a charge stop signal (e.g., through the communicator 22) requesting output stop to the controller 23. For example, when full charge is detected as a charge stop condition, the battery management module 11 may send an output stop signal to the controller 23.

[0078] In addition, when receiving the charge stop signal, the controller 23 may stop charging the battery pack 10. For example, when receiving the charge stop signal, the controller 23 may not output the charging voltage or the charging current.

[0079] Figure 5 An operation example of the controller 23 of the charger 20 according to the example embodiment is shown. Figure 5 Shows Figure 3 A detailed example of the operation of the controller 23 is shown. In addition, Figure 5 Operations S101, S102, S106, S107 and S108 may correspond to Figure 3 The operations are the same in number, and therefore, detailed descriptions thereof are omitted.

[0080] In operation S101 , the controller 23 may detect a connection between the charger 20 and the battery pack 10 through the connector 21 .

[0081] In operation S102, the controller 23 may output a wake-up voltage V1 (see FIG. 1 ) in response to detecting a connection with the battery pack 10. Figure 4 According to an example embodiment, it may take several milliseconds (ms) for the battery management module 11 to receive the wake-up voltage V1 and be activated.

[0082] In operation S201, through the communicator 22, the controller 23 can detect whether a battery voltage value is received from the battery management module 11. According to an exemplary embodiment, the controller 23 can identify whether a battery voltage value is received within a specific time period. For example, the specific time period can be set to the time taken to activate the battery management module 11. For example, the specific time period can be a few milliseconds to tens of milliseconds (ms). When the battery voltage value Vb is not received in operation S201, the controller 23 can continue operation S205, and when the number of retries is less than the specified number of times n, the controller 23 can retry. For example, a retry can indicate that the operation can start again from operation S101.

[0083] When the battery voltage value Vb is received within a certain period of time in operation S201, the controller 23 may proceed to operation S202 and may determine whether the battery voltage value Vb is greater than the wake-up voltage V1. When the battery cell 12 is normal, the battery voltage value Vb may be greater than the wake-up voltage V1.

[0084] When the battery voltage value Vb is less than the wake-up voltage V1, the controller 23 may continue to operate S205, and when the number of retries is less than the specified number n, the controller 23 may retry. When the number of retries is equal to or greater than the specified number n (for example, three times), the controller 23 may not start charging the battery pack 10. That is, the controller 23 may not output a charge start voltage, a charge voltage, or a charge current. Therefore, when the battery voltage value Vb is less than the wake-up voltage V1, the controller 23 may not start charging the battery pack 10.

[0085] When the battery voltage value Vb is greater than the wake-up voltage V1 in operation S202, the controller 23 may continue operation S203, and may detect whether the status information of the battery management module 11 is received from the battery management module 11. For example, the controller 23 may use the communicator 22 to detect whether the status information of the battery management module 11 is received within a specific time period. The status information may include, for example, status information of the battery cell 12. The status information may include, for example, a signal indicating whether the battery pack 10 is rechargeable.

[0086] For example, when the status information is not received within a certain period of time, the controller 23 may continue operation S205. When the number of retries is less than the specified number of times n, the controller 23 may, for example, retry from operation S101. When the number of retries is equal to or greater than the specified number of times n, the controller 23 may not start charging the battery pack 10.

[0087] When the status information of the battery management module 11 is received within a certain period of time, the controller 23 may continue operation S204 and detect whether the battery pack 10 is rechargeable. Based on the received status information, the controller 23 may detect whether the battery pack 10 is rechargeable.

[0088] When the status information indicates that it is impossible to recharge the battery pack 10, the controller 23 may continue operation S205, and when the number of recharges is less than the specified number of times n (e.g., three times), the controller 23 may retry. When the number of retries is equal to or greater than the specified number of times n, the controller 23 may not start charging the battery pack 10.

[0089] When the state information indicates that the battery pack 10 is rechargeable, the controller 23 may continue operation S106 and may determine the charge start voltage V2.

[0090] In operation S107, the controller 23 may output the determined charge start voltage V2. For example, the battery management module 11 may allow a charging current to flow by switching the charging device 14 to an on state based on the receipt of the charge start voltage V2.

[0091] In operation S108, the controller 23 may start charging the battery pack 10. According to an example embodiment, the controller 23 may output a preset charging current Ic based on the detection of the charging current, and may then output a preset charging voltage Vc.

[0092] The order of operations S201 to S204 and S106 is not limited to the order described. For example, the above order may be changed, and the operations may be performed in parallel or independently.

[0093] Figure 6 Examples of graphs G1 and G2 of the output voltage of the charger 20 according to various example embodiments are shown.

[0094] Referring to the graph G1, the controller 23 of the charger 20 may receive the battery voltage value Vb from the battery management module 11 while outputting the wake-up voltage V1, and may gradually increase the output voltage to the output start voltage V2 during a certain period of time. The controller 23 may stabilize the initial output voltage of the charger 20 by gradually increasing the output from the wake-up voltage V1 to the output start voltage V2.

[0095] Referring to graph G2, the controller 23 of the charger 20 according to another exemplary embodiment may receive the battery voltage value Vb while outputting the wake-up voltage V1, and may then increase the output voltage to the output start voltage V2 in a short time. For example, the controller 23 may output a first voltage lower than the output start voltage V2 in a short time, and may then gradually increase the voltage from the first voltage to the output start voltage V2. For example, the controller 23 may output a maximum voltage that may be controlled at the output start voltage V2 in a short time, and may then gradually increase the output voltage to the output start voltage V2. The charger 20 may shorten the time it takes to stabilize the initial output voltage.

[0096] As a summary and review, in order to reduce the inrush current generated by the output of the charger, there are some methods of designing the circuit, such as adding capacitors, or using circuit components with large ratings. However, when the output voltage or output current of the charger is large, the size of the circuit components for reducing the inrush current increases.

[0097] According to one or more embodiments, the inrush current may be reduced by controlling the output voltage of the charger. In addition, the ratings of circuit components used to reduce the inrush current may be reduced in the charging system.

[0098] Exemplary embodiments have been disclosed herein, and although specific terms are used, they are used and interpreted only in a general and descriptive sense, and not for purposes of limitation. In some cases, it will be apparent to one of ordinary skill in the art, such as submitting this application, that features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in conjunction with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise specifically noted. Therefore, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims

1. A charging system comprising: a battery pack including at least one battery cell and a switch connected in series between a first battery pack terminal and a second battery pack terminal, and a battery management module connected to the data terminal; and A charger including a connector configured to detect connection with a battery pack, a communicator configured to communicate with a battery management module through a data terminal, and a controller configured to control charging of the battery pack through a first battery pack terminal and a second battery pack terminal, The charger controller is configured as follows: When a connection with the battery pack is detected through the connector, a wake-up voltage is output between the first battery pack terminal and the second battery pack terminal to activate the battery management module; receiving data indicating a battery voltage value from a battery management module via a communicator; determining a charge start voltage based on the battery voltage value; outputting a charge start voltage between the first battery pack terminal and the second battery pack terminal; and After the charging start voltage is output, the battery pack starts to be charged by turning on the switch by the battery management module; The controller of the charger is configured to determine the charging start voltage to be greater than the battery voltage value by a preset margin value; The margin value is preset based on a line resistance value of the at least one battery cell and a preset charging current value.

2. The charging system according to claim 1, wherein: The controller of the charger is configured to output a charging current having a preset magnitude to the at least one battery cell and output a charging voltage having a preset magnitude to the battery pack when the battery pack starts to be charged.

3. The charging system according to claim 1, wherein: When the at least one battery unit does not supply power to the load and does not receive power from the charger within a preset time period, the battery management module is deactivated, and When the wake-up voltage is received, the battery management module is activated.

4. The charging system according to claim 1, wherein: The battery management module is configured to detect connection with the charger by receiving a signal transmitted from a communicator of the charger. 5 . The charging system of claim 1 , wherein the battery pack further comprises a switch configured to forcibly activate the battery management module.

6. The charging system according to claim 1, wherein: The battery management module is configured to send a charge stop signal requesting output stop to a controller of the charger when a charge stop condition is detected.

7. The charging system according to claim 6, wherein: The controller of the charger is configured to stop charging the battery pack when a charge stop signal is received, and to output a voltage or current to the battery pack or the other battery pack when release of the connection with the battery pack is detected and then connection with the battery pack or the other battery pack is detected again.

8. The charging system according to claim 6, wherein the controller of the charger is configured not to charge the battery pack even if the battery pack is connected until it is detected that the connection with the battery pack is released after receiving the charging stop signal.

9. The charging system according to claim 1, wherein: The controller of the charger is configured not to start charging the battery pack when the battery voltage value is less than the wake-up voltage.

10. A charger, comprising: a connector configured to detect connection to a battery pack including at least one battery cell and a switch connected in series between a first battery pack terminal and a second battery pack terminal; a communicator configured to communicate with a battery management module of the battery pack through a data terminal; and a controller configured to control charging of the battery pack, Wherein the controller is configured to: When a connection with the battery pack is detected through the connector, a wake-up voltage is output between the first battery pack terminal and the second battery pack terminal to activate the battery management module; receiving data indicating a battery voltage value from a battery management module via a communicator; determining a charge start voltage based on the battery voltage value; outputting a charge start voltage between the first battery terminal and the second battery terminal, and After the charging start voltage is output, the battery pack starts to be charged by turning on the switch by the battery management module; The controller is configured to determine the charging start voltage to be greater than the battery voltage value by a preset margin value; The margin value is preset based on a line resistance value of the at least one battery cell and a preset charging current value.

11. The charger according to claim 10, wherein: The controller is configured to output a charging current having a preset magnitude to the at least one battery cell and output a charging voltage having a preset magnitude to the battery pack when the battery pack starts to be charged.

12. The charger according to claim 10, wherein: The controller is configured to send a signal to the battery management module through the communicator to allow the battery management module to detect connection with the charger.

13. The charger according to claim 10, wherein the controller is configured to: When a charging stop signal is received from the battery management module through the communicator, stopping charging the battery pack; and, When release of connection with the battery pack is detected and then connection with the battery pack or another battery pack is detected again, a voltage or a current is output to the battery pack or another battery pack.

14. The charger according to claim 13, wherein: The controller is configured not to charge the battery pack even if the battery pack is connected until a release of the connection with the battery pack is detected after receiving a charge stop signal from the battery management module through the communicator.

15. The charger according to claim 10, wherein: The controller is configured not to start charging the battery pack when the battery voltage value is less than the wake-up voltage.

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