Patent Publication Number: US-2021167612-A1

Title: Electronic device for managing multiple batteries connected in series and method for operating same

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is based on and claims priority under 35 U.S.C. 119 to Korean Patent Application No. 10-2019-0156435, filed on Nov. 29, 2019, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. 
     BACKGROUND 
     1. Field 
     The present disclosure relates generally to an apparatus and a method for managing multiple batteries connected in series in connection with an electronic device, 
     2. Description of Related Art 
     In line with development of information/communication technologies and semiconductor technologies, various electronic device have been developed as multimedia devices providing various multimedia services, For example, the multimedia services may include at least one of a voice communication service, a message service, a broadcasting service, a wireless Internet service, a camera service, an electronic payment service, or a music playback service. 
     Each electronic device employs, as its power source, a battery having a limited power capacity in order to provide the user with portability and movability. The user of an electronic device, which employs a battery as its power source, can move out of the wired environment for powering the electronic device and thus use the electronic device more conveniently. 
     An electronic device may include at least one battery (e.g., a pack of batteries or a cell of batteries). An electronic device may include multiple batteries connected in series or in parallel. 
     An electronic device including multiple batteries connected in series may require an additional circuit for controlling the batteries. If an electronic device supplies power to a system through multiple batteries connected in series, the electronic device requires a voltage divider or a step-down converter for dropping the battery voltage to a predetermined level. The electronic device requires a balancing circuit for battery balancing such that no imbalance occurs in connection with charging/discharging of the multiple batteries. 
     SUMMARY 
     The present disclosure has been made to address at least the disadvantages described above and to provide at least the advantages described below. 
     In accordance with an aspect of the present disclosure, an electronic device is provided. The electronic device includes a voltage divider circuit, a first battery electrically connected to a first point of the voltage divider circuit, and a second battery connected in series to the first battery. A second point different from the first point of the voltage divider circuit is electrically connected from a first node on an electric path through which the first battery and the second battery are electrically connected. 
     In accordance with an aspect of the present disclosure, a method for operating an electronic device is provided. The method includes identifying voltages of a first battery and a second battery connected in series, and turning on a voltage divider circuit in case that a voltage difference between the first battery and the second battery satisfies a designated first condition, the voltage divider circuit having a first point connected to the first battery and having a second point which is different from the first point, connected to a first node on an electric path through which the first battery and the second battery are electrically connected. 
     In accordance with an aspect of the present disclosure, an electronic device is provided. The electronic device includes a first battery, a second battery connected in series to the first battery, a power management module configured to control charging and/or discharging of the first battery and the second battery, and a processor operatively connected to the power management module. The power management module comprises a voltage divider circuit having a first point connected to the first battery and having a second point, which is different from the first point, connected to a node on an electric path through which the first battery and the second battery are electrically connected. The processor is configured to turn on the voltage divider circuit in case that a voltage difference between the first battery and the second battery satisfies a designated condition. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and advantages of certain embodiments of the disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a block diagram of an electronic device inside a network environment, according to an embodiment; 
         FIG. 2A  is a diagram illustrating a foldable electronic device, according to an embodiment; 
         FIG. 2B  is a block diagram of an electronic device for controlling the charging/discharging of batteries, according to an embodiment; 
         FIG. 3  illustrates a configuration for discharging/discharging batteries, according to an embodiment; 
         FIG. 4A  illustrates the configuration of a voltage divider circuit, according to an embodiment; 
         FIG. 4B  illustrates the configuration of a voltage divider circuit, according to an embodiment; 
         FIG. 4C  illustrates the configuration of a voltage divider circuit, according to an embodiment; 
         FIG. 5A  illustrates a configuration for balancing batteries during high-voltage charging, according to an embodiment; 
         FIG. 5B  illustrates a configuration for balancing batteries during high-voltage charging, according to an embodiment; 
         FIG. 5C  illustrates a configuration for balancing batteries during high-voltage charging, according to an embodiment; 
         FIG. 6A  illustrates a configuration for balancing batteries during low-voltage charging, according to an embodiment; 
         FIG. 6B  illustrates a configuration for balancing batteries during low-voltage charging, according to an embodiment; 
         FIG. 6C  illustrates a configuration for balancing batteries during low-voltage charging, according to an embodiment; 
         FIG. 7A  illustrates a configuration for balancing batteries during system power supply, according to an embodiment; 
         FIG. 7B  illustrates a configuration for balancing batteries during system power supply, according to an embodiment; 
         FIG. 7C  illustrates a configuration for balancing batteries during system power supply, according to an embodiment; 
         FIG. 8A  illustrates a configuration for balancing batteries when power is supplied to an external electronic device, according to an embodiment; 
         FIG. 8B  illustrates a configuration for balancing batteries when power is supplied to an external electronic device, according to an embodiment; 
         FIG. 8C  illustrates a configuration for balancing batteries when power is supplied to an external electronic device, according to an embodiment; 
         FIG. 9  is a flowchart for a method of controlling a voltage divider circuit in connection with an electronic device, according to an embodiment; 
         FIG. 10  is a flowchart for a method of controlling a voltage divider circuit based on a voltage difference between batteries in connection with an electronic device, according to an embodiment; 
         FIG. 11  is a flowchart for a method of determining the operating mode of a voltage divider circuit based on a voltage difference between batteries in connection with an electronic device, according to an embodiment; 
         FIG. 12  is a flowchart for a method of configuring an on-resistance of a transistor in connection with an electronic device, according to an embodiment; 
         FIG. 13A  is a graph illustrating a change in the amount of current with regard to the on-resistance of a transistor, according to an embodiment; 
         FIG. 13B  is a graph illustrating a change in the amount of current with regard to the on-resistance of a transistor, according to an embodiment; and 
         FIG. 14  is a graph illustrating battery balancing with regard to the on-resistance of a transistor, according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, various embodiments will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a block diagram illustrating an electronic device  101  in a network environment  100 , according to an embodiment. Referring to FIG. the electronic device  101  in the network environment  100  may communicate with an electronic device  102  via a first network  198  (e.g., a short-range wireless communication network), or an electronic device  104  or a server  108  via a second network  199  (e.g., a long-range wireless communication network). According to an embodiment, the electronic device  101 . may communicate with the electronic device  104  via the server  108 . According to an embodiment, the electronic device  101  may include a processor  120 , memory  130 , an input device  150 , a sound output device  155 , a display device  160 , an audio module  170 , a sensor module  176 , an interface  177 , a haptic module  179 , a camera module  180 , a power management module  188 , a battery  189 , a communication module  190 , a subscriber identification module (SIM)  196 , or an antenna module  197 . In some embodiments, at least one (e.g., the display device  160  or the camera module  180 ) of the components may be omitted from the electronic device  101 , or one or more other components may be added in the electronic device  101 . In some embodiments, some of the components may be implemented as single integrated circuitry. For example, the sensor module  176  (e.g., a fingerprint sensor, an iris sensor, or an illuminance sensor) may be implemented as embedded in the display device  160  (e.g., a display). 
     The processor  120  may execute, for example, software (e.g., a program  140 ) to control at least one other component (e.g., a hardware or software component) of the electronic device  101  coupled with the processor  120 , and may perform various data processing or computation. According to an example embodiment, as at least part of the data processing or computation, the processor  120  may load a command or data received from another component (e.g., the sensor module  176  or the communication module  190 ) in volatile memory  132 , process the command or the data stored in the volatile memory  132 , and store resulting data in non-volatile memory  134 , According to an embodiment, the processor  120  may include a main processor  121  (e.g., a central processing unit (CPU) or an application processor (AP)), and an auxiliary processor  123  (e.g., a graphics processing unit (GPU), an image signal processor (ISP), a sensor hub processor, or a communication processor (CP)) that is operable independently from, or in conjunction with, the main processor  121 . Additionally or alternatively, the auxiliary processor  123  may be adapted to consume less power than the main processor  121 , or to be specific to a specified function. The auxiliary processor  123  may be implemented as separate from, or as part of the main processor  121 . 
     The auxiliary processor  123  may control at least some of functions or states related to at least one component (e.g., the display device  160 , the sensor module  176 , or the communication module  190 ) among the components of the electronic device  101 , instead of the main processor  121  while the main processor  121  is in an inactive (e.g., sleep) state, or together with the main processor  121  while the main processor  121  is in an active state (e.g., executing an application). According to an embodiment, the auxiliary processor  123  (e.g., an ISP or a CP) may be implemented as part of another component (e.g., the camera module  180  or the communication module  190 ) functionally related to the auxiliary processor  123 . 
     The memory  130  may store various data used by at least one component (e.g., the processor  120  or the sensor module  176 ) of the electronic device  101 . The various data may include, for example, software (e.g., the program  140 ) and input data or output data for a command related thereto. The memory  130  may include the volatile memory  132  or the non-volatile memory  134 . 
     The program  140  may be stored in the memory  130  as software, and may include, for example, an operating system (OS)  142 , middleware  144 , or an application  146 . 
     The input device  150  may receive a command or data to be used by other component (e.g., the processor  120 ) of the electronic device  101 , from the outside (e.g., a user) of the electronic device  101 . The input device  150  may include, for example, a microphone, a mouse, a keyboard, or a digital pen (e.g., stylus pen). 
     The sound output device  155  may output sound signals to the outside of the electronic device  101 . The sound output device  155  may include, for example, a speaker or a receiver. The speaker may be used for general purposes, such as playing multimedia or playing record, and the receiver may be used for an incoming calls. According to an embodiment, the receiver may be implemented as separate from, or as part of the speaker. 
     The display device  160  may visually provide information to the outside (e.g., a user) of the electronic device  101 . The display device  160  may include, for example, a display, a hologram device, or a projector and control circuitry to control a corresponding one of the display, hologram device, and projector. According to an embodiment, the display device  160  may include touch circuitry adapted to detect a touch, or sensor circuitry (e.g., a pressure sensor) adapted to measure the intensity of force incurred by the touch. 
     The audio module  170  may convert a sound into an electrical signal and vice versa. According to an embodiment, the audio module  170  may obtain the sound via the input device  150 , or output the sound via the sound output device  155  or a headphone of an external electronic device (e.g., an electronic device  102 ) directly (e.g., wiredly) or wirelessly coupled with the electronic device  101 . 
     The sensor module  176  may detect an operational state (e.g., power or temperature) of the electronic device  101  or an environmental state a state of a user) external to the electronic device  101 , and then generate an electrical signal or data value corresponding to the detected state. According to an embodiment, the sensor module  176  may include, for example, a gesture sensor, a gyro sensor, an atmospheric pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an infrared (IR) sensor, a biometric sensor, a temperature sensor, a humidity sensor, or an illuminance sensor. 
     The interface  177  may support one or more specified protocols to be used for the electronic device  101  to be coupled with the external electronic device (e.g., the electronic device  102 ) directly (e.g., wiredly) or wirelessly. According to an embodiment, the interface  177  may include, for example, a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, a secure digital (SD) card interface, or an audio interface. 
     A connecting terminal  178  may include a connector via which the electronic device  101  may be physically connected with the external electronic device (e.g., the electronic device  102 ). According to an embodiment, the connecting terminal  178  may include, for example, a connector, a USB connector, a SD card connector, or an audio connector (e.g., a headphone connector). 
     The haptic module  179  may convert an electrical signal into a mechanical stimulus (e.g., a vibration or a movement) or electrical stimulus which may be recognized by a user via his tactile sensation or kinesthetic sensation. According to an embodiment, the haptic module  179  may include, for example, a motor, a piezoelectric element, or an electric stimulator. 
     The camera module  180  may capture a still image or moving images. According to an embodiment, the camera module  180  may include one or more lenses, image sensors, ISPs, or flashes. 
     The power management module  188  may manage power supplied to the electronic device  101 . According to an example embodiment, the power management module  188  may be implemented as at least part of, for example, a power management integrated circuit (PMIC). 
     The battery  189  may supply power to at least one component of the electronic device  101 . According to an embodiment, the battery  189  may include, for example, a primary cell which is not rechargeable, a secondary cell which is rechargeable, or a fuel cell. 
     The communication module  190  may support establishing a direct (e.g., wired.) communication channel or a wireless communication channel between the electronic device  101  and the external electronic device (e.g., the electronic device  102 , the electronic device  104 , or the server  108 ) and performing communication via the established communication channel. The communication module  190  may include one or more CPs that are operable independently from the processor  120  (e.g., the AP) and supports a direct (e.g., wired) communication or a wireless communication. According to an embodiment, the communication module  190  may include a wireless communication module  192  (e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GLASS) communication module) or a wired communication module  194  (e.g., a local area network (LAN) communication module or a power line communication (PLC) module). A corresponding one of these communication modules may communicate with the external electronic device via the first network  198  a short-range communication network, such as Bluetooth™, wireless-fidelity (Wi-Fi) direct, or infrared data association (IrDA)) or the second network  199  (e.g., a long-range communication network, such as a cellular network, the Internet, or a computer network (e.g., LAN or wide area network (WAN)). These various types of communication modules may be implemented as a single component (e.g., a single chip), or may be implemented as multi components (e.g., multi chips) separate from each other. The wireless communication module  192  may identify and authenticate the electronic device  101  in a communication network, such as the first network  198  or the second network  199 , using subscriber information (e.g., international mobile subscriber identity (IMSI)) stored in the subscriber identification module  196 , 
     The antenna module  197  may transmit or receive a signal or power to or from the outside (e.g., the external electronic device) of the electronic device  101 . According to an embodiment, the antenna module  197  may include an antenna including a radiating element composed of a conductive material or a conductive pattern formed. in or on a substrate (e.g., PCB). According to an embodiment, the antenna module  197  may include a plurality of antennas, in such a case, at least one antenna appropriate for a communication scheme used in the communication network, such as the first network  198  or the second network  199 , may be selected, for example, by the communication module  190  (e.g., the wireless communication module  192 ) from the plurality of antennas, The signal or the power may then be transmitted or received between the communication module  190  and the external electronic device via the selected at least one antenna. According to an embodiment, another component (e.g., a radio frequency integrated circuit (MC)) other than the radiating element may be additionally formed as part of the antenna module  197 . 
     At least some of the above-described components may be coupled mutually and communicate signals (e.g., commands or data) therebetween via an inter-peripheral communication scheme (e.g., a bus, general purpose input and output (GPIO), serial peripheral interface (SPI), or mobile industry processor interface (MIPI)). 
     According to an embodiment, commands or data may be transmitted or received between the electronic device  101  and the external electronic device  104  via the server  108  coupled with the second network  199 . Each of the external electronic devices  102  and  104  may be a device of a same type as, or a different type, from the electronic device  101 , According to an embodiment, all or some of operations to be executed at the electronic device  101  may be executed at one or more of the external electronic devices  102 ,  104 , or  108 . For example, if the electronic device  101  should perform a function or a service automatically, or in response to a request from a user or another device, the electronic device  101 , instead of, or in addition to, executing the function or the service, may request the one or more external electronic devices to perform at least part of the function or the service. The one or more external electronic devices receiving the request may perform the at least part of the function or the service requested, or an additional function or an additional service related to the request, and transfer an outcome of the performing to the electronic device  101 . The electronic device  101  may provide the outcome, with or without further processing of the outcome, as at least part of a reply to the request. To that end, a cloud computing, distributed computing, or client-server computing technology may be used, for example. 
     The electronic device according to various embodiments may be one of various types of electronic devices. The electronic devices may include, for example, a portable communication device (e.g., a smart phone), a computer device, a portable multimedia device, a portable medical device, a camera, a wearable device, or a home appliance. According to an embodiment of the disclosure, the electronic devices are not limited to those described above. 
     It should be appreciated that various embodiments of the disclosure and the terms used therein are not intended to limit the technological features set forth herein to particular embodiments and include various changes, equivalents, or replacements for a corresponding embodiment. With regard to the description of the drawings, similar reference numerals may be used to refer to similar or related elements. It is to be understood that a singular form of a noun corresponding to an item may include one or more of the things, unless the relevant context clearly indicates otherwise. As used herein, each of such phrases as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B, or C,” “at least one of A, B, and C,” and “at least one of A, B, or C,” may include all possible combinations of the items enumerated together in a corresponding one of the phrases. As used herein, such terms as “1st” and “2nd,” or “first” and “second” may be used to simply distinguish a corresponding component from another, and does not limit the components in other aspect (e.g., importance or order). It is to be understood that if an element (e.g., a first element) is referred to, with or without the term “operatively” or “communicatively”, as “coupled with,” “coupled to,” “connected with,” or “connected to” another element (e.g., a second element), the element may be coupled with the other element directly (e.g., wiredly), wirelessly, or via a third element. 
     As used herein, the term “module” may include a unit implemented in hardware, software, or firmware, or any combination thereof, and may interchangeably be used with other terms, for example, “logic,” “logic block,” “part,” or “circuitry”. A module may be a single integral component, or a minimum unit or part thereof, adapted to perform one or more functions. For example, according to an embodiment of the disclosure, the module may be implemented in a form of an application-specific integrated circuit (ASIC). 
     Various embodiments as set forth herein may be implemented as software (e.g., the program  140 ) including one or more instructions that are stored in a storage medium (e.g., an internal memory  136  or an external memory  138 ) that is readable by a machine (e.g., the electronic device  101 ). For example, a processor (e.g., the processor  120 ) of the machine the electronic device  101 ) may invoke at least one of the one or more instructions stored in the storage medium, and execute it, with or without using one or more other components under the control of the processor. This allows the machine to be operated to perform at least one function according to the at least one instruction invoked. The one or more instructions may include a code generated by a compiler or a code executable by an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Wherein, the “non-transitory” storage medium is a tangible device, and does not include a signal (e.g., an electromagnetic wave), but this term may not differentiate between where data is semi-permanently stored in the storage medium and where the data is temporarily stored in the storage medium. 
     A method according to various embodiments of the disclosure may be included and provided in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read only memory (CD-ROM)), or be distributed (e.g., downloaded or uploaded) online via an application store (e.g., Play Store™) or between two user devices (e.g., smart phones) directly. If distributed online, at least part of the computer program product may be temporarily generated or at least temporarily stored in the machine-readable storage medium, such as memory of the manufacturer&#39;s server, a server of the application store, or a relay server. 
     According to various embodiments of the disclosure, each component (e.g., a module or a program) of the above-described components may include a single entity or multiple entities. According to various embodiments of the disclosure, one or more of the above-described components may be omitted, or one or more other components may be added. Alternatively or additionally, a plurality of components (e.g., modules or programs) may be integrated into a single component. In such a case, according to various embodiments of the disclosure, the integrated component may still perform one or more functions of each of the plurality of components in the same or similar manner as they are performed by a corresponding one of the plurality of components before the integration. According to various embodiments of the disclosure, operations performed by the module, the program, or another component may be carried out sequentially, in parallel, repeatedly, or heuristically, or one or more of the operations may be executed in a different order or omitted, or one or more other operations may be added. 
       FIG. 2A  is a diagram illustrating a foldable electronic device, according to an embodiment. The electronic device  201  in the following description may be the electronic device  101  in  FIG. 1 . 
     Referring to  FIG. 2A , the electronic device  201  may include a pair of housing structures  210  and  220  (e.g., foldable housing structures) coupled to be able to rotate with reference to folding axis A (e.g., a folding axis in the vertical or horizontal direction) through a hinge structure  240  such that they are folded with regard to each other, and a display  230  (e.g., a flexible display or a foldable display) positioned in a space formed by the pair of housing structures  210  and  220 . The surface on which the display  230  is positioned may be defined as the front surface of the electronic device  201 , and the opposite surface of the front surface may be defined as the rear surface of the electronic device  201  In addition, a surface surrounding the space between the front and rear surfaces may be defined as a side surface of the electronic device  201 . 
     The pair of housing structures  210  and  220  may include a first housing structure  210  and a second housing structure  220 . The pair of housing structures  210  and  220  of the electronic device  201  is not limited to the type and coupling illustrated in  FIG. 2A , and may be implemented by a combination and/or coupling of other shapes or components. 
     The first housing structure  210  and the second housing structure  220  may be positioned on both sides around the folding axis (axis A), and may have overall shapes symmetric with regard to the folding axis (axis A). The angle or distance between the first housing structure  210  and the second housing structure  220  may vary depending on whether the electronic device  201  is in a flat state, in a folding state, or in an intermediate state. 
     The first housing structure  210  may include an area in which a camera  214  and various sensors  215  are positioned, unlike the second housing structure  220 , but other areas thereof may have mutually symmetric shapes. The area in which a camera  214  and various sensors  215  are positioned may be additionally positioned in at least a partial area of the second housing structure  220  or may be replaced. 
     The first housing structure) may include a first surface  211  connected to the hinge structure  240  and positioned to face the front surface of the electronic device  201 , in the flat state of the electronic device  201 , a second surface  212  facing away from the first surface  211  and a first side member  213  surrounding at least a part of the space between the first surface  211  and the second surface  212 . 
     The second housing structure  220  may include a third surface  221  connected to the hinge structure  240  and positioned to face the front surface of the electronic device  201  in the flat state of the electronic device  201 , a fourth surface  222  facing away from the third surface  221 , and a second side member  223  surrounding at least a part of the space between the third surface  221  and the fourth surface  222 . The first surface  211  may be configured to face the third surface  221  in an infolding-type folding state. The second surface  212  may be configured to face the fourth surface  222  in an outfolding-type folding state. 
     The camera  214  and the sensors  215  may be positioned in a predetermined area on a corner of the first housing structure  210 . However, the position of the camera  214  and the sensors  215  is not limited to the illustrated example. The camera  214  and the sensors  215  may be positioned in at least a partial area of the second housing structure  220 . The camera  214  and the sensors  215  may be positioned in at least a partial area of the first housing structure  210  and the second housing structure  220 . 
     The camera  214  may be exposed to the front surface of the electronic device  201  through an opening provided in a corner of the first housing structure  210 . The camera  214  may be positioned at the lower end of at least a partial area of the display  230 . 
     The sensors  215  may be positioned at the lower end of at least a partial area of the display  230 . The sensors  215  may include at least one of a proximity sensor, an illuminance sensor, an iris recognition sensor, an ultraviolet sensor, or an indicator. The sensors  215  may be exposed to the front surface of the electronic device  201  through an opening provided in a corner of the first housing  210 . The first housing structure  210  may include a receiver  216  positioned through at least a partial area, and an interface connector port  217 . 
     The first housing structure  210  and the second housing structure  220  may provide, through an intercoupled structure, a space in which various components of the electronic device  201  (e.g., a printed circuit board, an antenna module, a sensor module, or a battery) can be positioned. One or more components may be positioned on the rear surface of the electronic device  201 , or may be visually exposed therethrough. One or more components or sensors may be visually exposed through the rear surface  222  of the second housing structure  220 . The sensors may include a proximity sensor, a rear camera device, and/or a flash. At least a part of a sub-display may be visually exposed through the rear surface  222  of the second housing structure  220 . 
     The display  230  may be positioned in a space formed by the pair of housing structures  210  and  220 . The display  230  may be seated in a recess formed by the pair of housing structures  210  and  220 , and may be positioned to occupy substantially the majority of the front surface of the electronic device  201 . Accordingly, the front surface of the electronic device  201  may include a display  230 , and a partial area a boundary area) of the first housing structure  210  and a partial area (e.g., a boundary area) of the second housing structure  220 , which are adjacent to the display  230 . Multiple displays  230  may be configured. Some displays  230  may be positioned on the first housing structure  210 , and other displays  230  may be positioned on the second housing structure  220 . 
     The electronic device  201  may include a first battery  252  a pack of batteries or a cell of batteries) positioned on at least a part of the first housing structure  210  and a second battery  254  (e.g., a pack of batteries or a cell of batteries) positioned on at least a part of the second housing structure  220 . The first battery  252  and the second battery  254  may be connected in series. At least one of the type or capacity (or maximum capacity) of the first battery  252  and the second battery  254  may be identical or different. 
     The electronic device  201  may include multiple housings (e.g., first to third housings) positioned to be able to rotate with regard to each other. The first housing and the second housing may be connected to be able to rotate with regard to each other with reference to a first axis of rotation through a first hinge module. The first housing and the third housing may be connected to be able to rotate with regard to each other with reference to a second axis of rotation through a second hinge module. The second housing may be coupled to one side of the first housing through the first hinge module, and the third housing may be coupled to the other side of the first housing through the second hinge module. The first housing, the second housing, and/or the third housing may include a battery positioned on at least a part thereof. Batteries positioned on the housings may be connected in series. 
       FIG. 2B  is a block diagram of an electronic device for controlling the charging/discharging of batteries, according to an embodiment. In the following description, the electronic device  201  may include at least some of the components of the electronic device  101  in  FIG. 1 . At least some components in  FIG. 2B  may hereinafter be described with reference to  FIG. 3 .  FIG. 3  illustrates a configuration for discharging/discharging batteries, according to an embodiment. 
     Referring to  FIG. 2B , the electronic device  201  may include batteries  252  and  254 , a power management module  260 , and a processor  270 . The batteries  252  and  254  may be identical to the battery  189  in  FIG. 1  or may be included in the battery  189 . The power management module  260  may be identical to the power management module  188  in  FIG. 1  or may be included in the power management module  188 . The processor  270  may be identical to the main processor  121  in  FIG. 1  or may be included in the main processor  121 . The processor  270  may include an AP, a sensor hub processor, or a micro controller unit (MCU) processor. 
     The batteries  252  and  254  may be connected in series. At least one of the type or capacity (or maximum capacity) of the first battery  252  and the second battery  254  may be identical or different. The second battery  254  may be configured to have a capacity relatively larger than or equal to that of the first battery  252 . The first battery  252  may be electrically connected to a first node  311  and a second node  312  as in  FIG. 3 . The second battery  254  may be electrically connected between the first node  311  and a first ground unit  317 . The first node  311  may be included in an electric path through which the first battery  252  and the second battery  254  are connected in series. The second node  312  may be included in an electric path through which a first point  315  of a voltage divider circuit  264  is connected to a first pole (e.g., pole) of the first battery  252 . 
     The power management module  260  may include a charging circuit  262 , a voltage divider circuit  264 , and/or a detecting module  266 . The charging circuit  262  may charge the batteries  252  and/or  254  by using power supplied from an external power source. The power management module  260  (or the processor  270 ) may select a charging scheme (e.g., normal charging, direct charging, or rapid charging) based on at least one of the type of the external power source (e.g., a power adapter, a USB, or wireless charging), the amount of power suppliable from the external power source (e.g., travel adapter (TA) or an external electronic device), or the attribute of the batteries  252  and/or  254 . The charging circuit  262  may charge the batteries  252  and/or  254  by using the high-voltage charging circuit  320  or the low-voltage charging circuit (or normal charging circuit)  330  in  FIG. 3 , based on the charging scheme. The high-voltage charging circuit  320  may be electrically connected to the second node  312  connected to the first battery  252 , as in  FIG. 3 . The low-voltage charging circuit  330  may be electrically connected to the third node  313 , as in  FIG. 3 . A capacitor  332  is positioned between the third node  313  and a second ground unit  318  so as to remove noise or high-frequency signals from power applied to the batteries  252  and/or  254 , and may include a bypass capacitor or a decoupling capacitor. The high-voltage charging circuit  320  and the lower-voltage charging circuit  330  may control charging of the batteries  252  and/or  254  according to a constant current (CC) scheme and/or a constant voltage (CV) scheme, based on the charging state of the batteries  252  and/or  254 . 
     The voltage divider circuit  264  may adjust the voltage level of power supplied from the external power source or the batteries  252  and/or  254  into a voltage level appropriate for components included in the electronic device  201 . The voltage divider circuit  264  may control balancing of the first battery  252  and the second battery  254 . The first point  315  of the voltage divider circuit  264  may be electrically connected to the second node  312 , as in  FIG. 3 . The second point  316  of the voltage divider circuit  264  may be connected to the first node  311  and the third node  313 , as in  FIG. 3 . The first point  315  and the second point  316  of the voltage divider circuit  264  may differ from each other. 
     The detecting module  266  may identify (or measure) use state information of the batteries  252  and/or  254 . The detecting module  266  may identify the voltage of the first battery  252  and the second battery  254 . 
     The processor  270  may control the voltage divider circuit  264  based on a voltage difference between the first battery  252  and the second battery  254  identified through the detecting module  266 . If the voltage difference between the first battery  252  and the second battery  254  exceeds a first reference voltage (e.g., about 100 mV), the processor  270  may control the voltage divider circuit  264  so as to operate in a first mode in which the voltage divider circuit  264  is turned on. If the voltage difference between the first battery  252  and the second battery  254  drops below a second reference voltage (e.g., about 60 mV) while the voltage divider circuit  264  operates in the first mode, the processor  270  may control the voltage divider circuit  264  so as to operate in a second mode in which at least a part of the voltage divider circuit  264  is turned on. If the voltage difference between the first battery  252  and the second battery  254  drops below a third reference voltage (e.g., about 20 mV) while the voltage divider circuit  264  operates in the second mode, the processor  270  may control the voltage divider circuit  264  so as to operate in a third mode in which the switching cycle of the voltage divider circuit  264  is adjusted. The switching cycle may include a cycle at which a transistor is turned on so as to connect the capacitor of the voltage divider circuit  264  and the first battery  252  or the second battery  254 . 
     The processor  270  may differently configure a reference related to switching of the operating mode of the voltage divider circuit  264 , in order to prevent frequent switching of the operating mode of the voltage divider circuit  264 . The processor  270  may differently configure a reference (e.g., about 60 mV) when switching from the first mode to the second mode and a reference (e.g., about 80 mV) when switching from the second mode to the first mode. The processor  270  may differently configure a reference (e.g., about 20 mV) when switching from the second mode to the third mode and a reference (e.g., about 40 mV) when switching from the third mode to the second mode. 
     The processor  270  may adjust the magnitude (or value) of on-resistance (RDson resistance) of a transistor constituting the voltage divider circuit  264 , in order to reduce a ripple current (or inrush current) resulting from switching of the voltage divider circuit  264 . if the voltage difference between the first battery  252  and the second battery  254  exceeds a reference voltage (e.g., about 200 mV), the processor  270  may control the voltage divider circuit  264  such that the on-resistance of the transistor is configured to have a first value (e.g., about 25 mΩ). If the voltage difference between the first battery  252  and the second battery  254  is equal to/lower than the reference voltage, the processor  270  may control the voltage divider circuit  264  such that the on-resistance of the transistor is configured to have a second value (e.g., about 10 mΩ). Configuring the on-resistance may include an operation of selecting a sub-divider circuit from a sub-divider circuit including a first value and a sub-divider circuit including a second value. Configuring the on-resistance may include an operation of changing the value of a variable resistance corresponding to the transistor. Switching the voltage divider circuit  264  may include an operation of changing the battery  252  or  254  connected to the voltage divider circuit  264  such that the voltage divider circuit  264  balances the batteries  252  and  254 . 
     At least some of the functions of the processor  270  may be performed by an external control device the power management module  260 ). 
       FIG. 4A  illustrates the configuration of a voltage divider circuit, according to an embodiment.  FIG. 4B  illustrates the configuration of a voltage divider circuit, according to an embodiment.  FIG. 4C  illustrates the configuration of a voltage divider circuit, according to an embodiment. The following descriptions may include internal components of the voltage divider circuit  264  in  FIG. 2B . 
     Referring to  FIG. 4A , the voltage divider circuit  264  may include a first transistor  402 , a second transistor  404 , a third transistor  406 , a fourth transistor  408 , and a first capacitor  410 . 
     The first transistor  402 , the second transistor  404 , the third transistor  406 , and the fourth transistor  408  may be connected in series, The first transistor  402  may be electrically connected between a second node  312  and a fourth node  412 . The second transistor  404  may be electrically connected between a second point  316  between the second transistor  404  and the third transistor  406  and a fourth node  412 . The third transistor  406  may be electrically connected between the second point  316  and a fifth node  414 . The fourth transistor  408  may be electrically connected between the fifth node  414  and a ground unit  409 . The second point  316  of the voltage divider circuit  264  may be included in an electric path through which the first node  311  and the third node  313  are electrically connected. The first transistor  402  and the third transistor  406  may be turned on at a first point in time as a pair. The second transistor  404  and the fourth transistor  408  may be turned on at a second point in time different from the first point in time as a pair. The first point in time and the second point in time may be alternately repeated at a predetermined cycle. The first transistor  402 , the second transistor  404 , the third transistor  406 , or the fourth transistor  408  may include a metal oxide semiconductor field effect transistor (MOSFET). 
     The first capacitor  410  may be electrically connected between the fourth node  412  and the fifth node  414  such that the same is electrically connected to the first battery  252  or the second battery  254  based on turning-on of multiple transistors  402 ,  404 ,  406 , or  408 . The first capacitor  410  may be electrically connected to the first battery  252  if the pair of the first transistor  402  and the third transistor  406  is turned on. The first capacitor  410  may be electrically connected to the second battery  254  if the pair of the second transistor  404  and the fourth transistor  408  is turned on. 
     Referring to  FIG. 4B , the voltage divider circuit  264  may include a first sub-divider circuit  420  and a second sub-divider circuit  440 . 
     The first sub-divider circuit  420  may include a fifth transistor  422 , a sixth transistor  424 , a seventh transistor  426 , an eighth transistor  428 , and a second capacitor  430 . The fifth transistor  422 , the sixth transistor  424 , the seventh transistor  426 , and the eighth transistor  428  may be connected in series. The fifth transistor  422  may be electrically connected between a sixth node  431  and a seventh node  432 . The sixth transistor  424  may be electrically connected between the seventh node  432  and an eighth node  434 . The seventh transistor  426  may be electrically connected between the eighth node  434  and a ninth node  436 . The eighth transistor  428  may be electrically connected between the ninth node  436  and a third ground unit  438 . The second capacitor  430  may be electrically connected between the seventh node  432  and the ninth node  436  such that the same is electrically connected to the first battery  252  or the second battery  254  based on turning-on of multiple transistors  422 ,  424 ,  426 , or  428 . The second capacitor  430  may be electrically connected to the first battery  252  if the pair of the fifth transistor  422  and the seventh transistor  426  is turned on, The second capacitor  430  may be electrically connected to the second battery  254  if the pair of the sixth transistor  424  and. the eighth transistor  428  is turned on. 
     The second sub-divider circuit  440  may include a ninth transistor  442 , a tenth transistor  444 , an eleventh transistor  446 , a twelfth transistor  448 . and a third capacitor  450 . The ninth transistor  442 , the tenth transistor  444 , the eleventh transistor  446 , and the twelfth transistor  448  may be connected in series. The ninth transistor  442  may be electrically connected between a sixth node  431  and a tenth node  452 . The tenth transistor  444  may be electrically connected between the tenth node  452  and an eleventh node  454 . The eleventh transistor  446  may be electrically connected between the eleventh node  454  and a twelfth node  156 . The twelfth transistor  448  may be electrically connected between the twelfth node  456  and a fourth ground unit  458 . The third capacitor  450  may be electrically connected between the tenth node  452  and the twelfth node  456  such that the same is electrically connected to the first battery  252  or the second battery  254  based on turning-on of multiple transistors  442 ,  444 ,  446 , or  448 . If the pair of the ninth transistor  442  and the eleventh transistor  446  is turned on, the third capacitor  430  may be electrically connected to the first battery  252 . If the pair of the tenth transistor  444  and the twelfth transistor  448  is turned on, the third capacitor  430  may be electrically connected to the second battery  254 . The second point  316  of the voltage divider circuit  264  may include the eighth node  434  and the eleventh node  454 . 
     The first sub-divider circuit  420  and the second sub-divider circuit  440  may be driven for balancing of the first battery  252  and the second battery  254 . If the processor  270  has determined an operation in the first mode, the voltage divider circuit  264  may turn on the first sub-divider circuit  420  and the second sub-divider circuit  440 , thereby controlling the charging/discharging and balancing of the batteries  252  and/or  254 . If the processor  270  has determined an operation in the second mode, the voltage divider circuit  264  may turn on the first sub-divider circuit  420  or the second sub-divider circuit  440 , thereby controlling the charging/discharging and balancing of the batteries  252  and/or  254 . 
     The first sub-divider circuit  420  and the second sub-divider circuit  440  may operate with opposite phases, in order to reduce the ripple current (or inrush current) resulting from switching of the voltage divider circuit  264 . The first sub-divider circuit  420  may turn on the pair of the fifth transistor  422  and the seventh transistor  426  such that the first battery  252  and the second capacitor  430  are electrically connected. In this case, the second sub-divider circuit  440  may turn on the pair of the tenth transistor  444  and the twelfth transistor  448  such that the second battery  254  and the third capacitor  450  are electrically connected. 
     Referring to  FIG. 4C , the voltage divider circuit  264  may include a third sub-divider circuit  460 , a fourth sub-divider circuit  480 , and a fourth capacitor  490 . 
     The third sub-divider circuit  460  may include a thirteenth transistor  462 , a fourteenth transistor  464 , a fifteenth transistor  466 , and a sixteenth transistor  468 . The thirteenth transistor  462 , the fourteenth transistor  464 , the fifteenth transistor  466 , and the sixteenth transistor  4688  may be connected in series. The thirteenth transistor  462  may be electrically connected between a thirteenth node  491  and a fourteenth node  492 . The fourteenth transistor  464  may be electrically connected between the fourteenth node  492  and a fifteenth node  493 . The fifteenth transistor  466  may be electrically connected between the fifteenth node  493  and a sixteenth node  494 . The sixteenth transistor  468  may be electrically connected between the sixteenth node  494  and a fifth ground unit  469 , 
     The fourth sub-divider circuit  480  may include a seventeenth transistor  482 , an eighteenth transistor  484 , a nineteenth transistor  486 , and a twentieth transistor  488 . The seventeenth transistor  482 , the eighteenth transistor  484 , the nineteenth transistor  486  and the twentieth transistor  488  may be connected in series. The seventeenth transistor  482  may be electrically connected between the thirteenth node  491  and a seventh node  495 . The eighteenth transistor  484  may be electrically connected between the seventeenth node  495  and an eighteenth node  496 . The nineteenth transistor  486  may be electrically connected between the eighteenth node  496  and a nineteenth node  497 . The twentieth transistor  488  may be electrically connected between the nineteenth node  497  and a sixth ground unit  489 . The second point  316  of the voltage divider circuit  264  may include the fifteenth node  493  and the eighteenth node  496 . 
     The third sub-divider circuit  460  and the fourth sub-divider circuit  480  may be synchronized in order to share the fourth capacitor  490 . The third sub-divider circuit  460  may turn on the pair of the thirteenth transistor  462  and the fifteenth transistor  466  such that the first battery  252  and the fourth capacitor  490  are electrically connected. In this case, the fourth sub-divider circuit  480  may turn on the pair of the seventeenth transistor  482  and the nineteenth transistor  486 , similarly to the third sub-divider circuit  460 , such that the first battery  252  and the fourth capacitor  490  are electrically connected. 
     The thirteenth transistor  462 , the fourteenth transistor  464 , the fifteenth transistor  466 , and the sixteenth transistor  468 , which are included in the third sub-divider circuit  460 , and the seventeenth transistor  482 , the eighteenth transistor  484 , the nineteenth transistor  486 , and the twentieth transistor  488 , which are included in the fourth sub-divider circuit  480 , may include different on-resistances (e.g., about 25 mΩ or about 10 mΩ). If the voltage difference between the first battery  252  and the second battery  254  exceeds a reference voltage (e.g., about 200 mV), the processor  270  may turn on the third sub-divider circuit  460  including an on-resistance having a first value (e.g., about 25 mΩ), in order to reduce the ripple current (or inrush current) resulting from switching of the voltage divider circuit  264 . If the voltage difference between the first battery  252  and the second battery  254  is equal to/lower than a reference voltage (e.g., about 200 mV), the processor  270  may turn on the fourth sub-divider circuit  480  including an on-resistance having a second value (e.g., about 10 mΩ). 
       FIG. 5A  illustrates a configuration for balancing batteries during high-voltage charging, according to an embodiment.  FIG. 5B  illustrates a configuration for balancing batteries during high-voltage charging, according to an embodiment.  FIG. 5C  illustrates a configuration for balancing batteries during high-voltage charging, according to an embodiment. It may be assumed in the following description that the capacity (or maximum capacity) of the first battery  252  is relatively smaller than that of the second battery  254 . 
     Referring to  FIG. 5A  to  FIG. 5C , the voltage divider circuit  264  may include a first transistor  402 , a second transistor  404 , a third transistor  406 , a fourth transistor  408 , and a first capacitor  410 . In the following description, internal components of the voltage divider circuit  264  may operate similarly to the internal components of the voltage divider circuit  264  in  FIG. 4A . The first transistor  402 , the second transistor  404 , the third transistor  406 , the fourth transistor  408 , and the first capacitor  410  in  FIG. 5A  to  FIG. 5C  may operate similarly to the first transistor  402 , the second transistor  404 , the third transistor  406 , the fourth transistor  408 , and the first capacitor  410  in  FIG. 4A . For this reason, detailed descriptions of internal components of the voltage divider circuit  264  will be omitted herein. 
     When charging the batteries  252  and/or  254  according to a high-voltage charging scheme, the high-voltage charging circuit  320  may apply ( 510 ) a charging current to the first battery  252  and the second battery  254 , as in  FIG. 5A . The first battery  252  and the second battery  254  may be charged based on the charging current applied from the high-voltage charging circuit  320 . If the capacity (or maximum capacity) of the first battery  252  is relatively smaller than that of the second battery  254 , the first battery  252 , even if charged with the same charging current, may maintain a relatively higher voltage than the second battery  254 . 
     The processor  270  may turn on the voltage divider circuit  264  if the voltage difference between the first battery  252  and the second battery  254  exceeds a reference voltage (e.g., about 100 mV), based on high-voltage charging. The voltage divider circuit  264 , if turned on by the processor  270 , may alternately turn on a first pair of the first transistor  402  and the third transistor  406  and a second pair of the second transistor  404  and the fourth transistor  408 . 
     If the first pair of transistors (e.g., the first transistor  402  and the third transistor  406 ) is turned on at a first point in time, the first capacitor  410  may be electrically connected to the first battery  252  through the first pair of transistors. The first capacitor  410 , if connected to the first battery  252 , may be charged ( 520 ) by a current provided from the first battery  252  having a voltage relatively higher than that of the second. battery  254 , as in  FIG. 5B . 
     If a second pair of transistors (e.g., the second transistor  404  and the fourth transistor  408 ) is turned on at a second point in time, the first capacitor  410  may be electrically connected to the second battery  254  through the second pair of transistors. If the first capacitor  410  is connected to the second battery  254 , energy accumulated by the first battery  252  may be provided to the second battery  254  having a voltage relatively lower than that of the first battery  252 , as in  FIG. 5C , thereby charging ( 530 ) the second battery  254 . As a result, energy accumulated in the first battery  252  and the second battery  254 , which has become unbalanced by the high-voltage charging circuit  320 , may become uniform by means of the voltage divider circuit  264 . 
       FIG. 6A  illustrates a configuration for balancing batteries during low-voltage charging, according to an embodiment.  FIG. 6B  illustrates a configuration for balancing batteries during low-voltage charging, according to an embodiment.  FIG. 6C  illustrates a configuration for balancing batteries during low-voltage charging, according to an embodiment. 
     Referring to  FIG. 6A  to  FIG. 6C , the voltage divider circuit  264  may include a first transistor  402 , a second transistor  404 , a third transistor  406 , a fourth transistor  408 , and a first capacitor  410 . In the following description, internal components of the voltage divider circuit  264  may operate similarly to the internal components of the voltage divider circuit  264  in  FIG. 4A . The first transistor  402 , the second transistor  404 , the third transistor  406 , the fourth transistor  408 , and the first capacitor  410  in  FIG. 6A  to  FIG. 6C  may operate similarly to the first transistor  402 , the second transistor  404 , the third transistor  406 , the fourth transistor  408 , and the first capacitor  410  in  FIG. 4A . For this reason, detailed descriptions of internal components of the voltage divider circuit  264  will be omitted herein. 
     When charging the batteries  252  and/or  254  according to a low-voltage charging scheme, the low-voltage charging circuit  330  may apply ( 610 ) a charging current to the first node  311  through the third node  313 , as in  FIG. 6A . The second battery  254  may be charged based on the charging current applied to the first node  311  from the low-voltage charging circuit  330 . Accordingly, the second battery  254  may maintain a relatively higher voltage than the first battery  252  to which no charging current is applied from the low-voltage charging circuit  330 . The first battery  252  to which no charging current is applied may represent a first battery  252  which is not provided with a charging current from the low-voltage charging circuit  330 , and which is thus not charged based on the low-voltage charging circuit  330 . However, the first battery  252  may be charged according to a low-voltage charging scheme, based on a balancing operation by the voltage divider circuit  264 . 
     The processor  270  may turn on the voltage divider circuit  264  if the voltage difference between the first battery  252  and the second battery  254  exceeds a reference voltage (e.g., about 100 mV), based on the low-voltage charging scheme. The voltage divider circuit  264 , if turned on by the processor  270 , may alternately turn on the first pair of the first transistor  402  and the third transistor  406  and the second pair of the second transistor  404  and the fourth transistor  408 . 
     If the second pair of transistors (e.g., the second transistor  404  and the fourth transistor  408 ) is turned on at a first point in time, the first capacitor  410  may be electrically connected to the second battery  254  through the second pair of transistors (e.g., the second transistor  404  and the fourth transistor  408 ). The first capacitor  410 , if connected to the second battery  254 , may be charged ( 620 ) by a current provided from the second battery  254  having a voltage relatively higher than that of the first battery  252 , as in  FIG. 6B . 
     If the first pair of transistors (e.g., the first transistor  402  and the third transistor  406 ) is turned on at a second point in time, the first capacitor  410  may be electrically connected to the first battery  252  through the first pair of transistors. If the first capacitor  410  is connected to the first battery  252 , energy accumulated by the second battery  254  may be provided to the first battery  252  having a voltage relatively lower than that of the second battery  254 , as in  FIG. 6C , thereby charging ( 630 ) the first battery  252 . As a result, energy accumulated in the first battery  252  and the second battery  254 , which has become unbalanced by the low-voltage charging circuit  320 , may become uniform by means of the voltage divider circuit  264 . 
       FIG. 7A  illustrates a configuration for balancing batteries during system power supply, according to an embodiment.  FIG. 7B  illustrates a configuration for balancing batteries during system power supply, according to an embodiment.  FIG. 7C  illustrates a configuration for balancing batteries during system power supply, according to an embodiment. 
     Referring to  FIG. 7A  to  FIG. 7C , the voltage divider circuit  264  may include a first transistor  402 , a second transistor  404 , a third transistor  406 , a fourth transistor  408 , and a first capacitor  410 . In the following description, internal components of the voltage divider circuit  264  may operate similarly to the internal components of the voltage divider circuit  264  in  FIG. 4A . The first transistor  402 , the second transistor  404 , the third transistor  406 , the fourth transistor  408 , and the first capacitor  410  in  FIG. 7A  to  FIG. 7C  may operate similarly to the first transistor  402 , the second transistor  404 , the third transistor  406 , the fourth transistor  408 , and the first capacitor  410  in  FIG. 4A . For this reason, detailed descriptions of internal components of the voltage divider circuit  264  will be omitted herein. 
     If the batteries  252  and/or  254  supply power (system power) to at least one component of the electronic device  201 , the second battery  254  may be discharged ( 710 ), in order to supply the system power, as in  FIG. 7A . Accordingly, the first battery  252  may maintain a voltage relatively higher than that of the second battery  254  discharged to supply the system power. 
     The processor  270  may turn on the voltage divider circuit  264  if the voltage difference between the first battery  252  and the second battery  254  exceeds a reference voltage (e.g., about 100 mV), based on system power supply. The voltage divider circuit  264 , if turned on by the processor  270 , may alternately turn on a first pair of the first transistor  402  and the third transistor  406  and a second pair of the second transistor  404  and the fourth transistor  408 . The first and second pairs of transistors may be alternately turned on at the same cycle. 
     If the first pair of transistors e.g., the first transistor  402  and the third transistor  406 ) is turned on at a first point in time, the first capacitor  410  may be electrically connected to the first battery  252  through the first pair of transistors, The first capacitor  410 , if connected to the first battery  252 , may be charged ( 720 ) by a current provided from the first battery  252  having a voltage relatively higher than that of the second battery  254 , as in  FIG. 7B . 
     If a second pair of transistors (e.g., the second transistor  404  and the fourth transistor  408 ) is turned on at a second point in time, the first capacitor  410  may supply ( 730 ), as system power, energy accumulated by the first battery  252  as in  FIG. 7C . The system power supplied by the first capacitor  410  may be supplied to at least one component of the electronic device  201  together with the energy discharged from the second battery  254 . As a result, energy accumulated in the first battery  252  and the second battery  254 , which has become unbalanced by the system power supply, may become uniform by means of the voltage divider circuit  264 . 
       FIG. 8A  illustrates a configuration for balancing batteries when power is supplied to an external electronic device (or internal electronic device), according to an embodiment.  FIG. 8B  illustrates a configuration for balancing batteries when power is supplied to an external electronic device (or internal electronic device), according to an embodiment.  FIG. 8C  illustrates a configuration for balancing batteries when power is supplied to an external electronic device (or internal electronic device), according to an embodiment. It may be assumed in the following description that the first battery  252  has a capacity (or maximum capacity) relatively smaller than that of the second battery  254 . 
     Referring to  FIG. 8A  to  FIG. 8C , the voltage divider circuit  264  may include a first transistor  402 , a second transistor  404 , a third transistor  406 , a fourth transistor  408 , and a first capacitor  410 . In the following description, internal components of the voltage divider circuit  264  may operate similarly to the internal components of the voltage divider circuit  264  in  FIG. 4A . For example, the first transistor  402 , the second transistor  404 , the third transistor  406 , the fourth transistor  408 , and the first capacitor  410  in  FIG. 8A  to  FIG. 8C  may operate similarly to the first transistor  402 , the second transistor  404 , the third transistor  406 , the fourth transistor  408 , and the first capacitor  410  in  FIG. 4A . For this reason, detailed descriptions of internal components of the voltage divider circuit  264  will be omitted herein. 
     If the batteries  252  and/or  254  supply power to an external electronic device (e.g., a direct current (DC)-DC convertor or a wireless charger), the first battery  252  and the second battery  254  connected in series may be discharged ( 810 ), as in  FIG. 8A . If the capacity (or maximum capacity) of the second battery  254  relatively larger than that of the first battery  252 , the voltage of the second battery  254  may be maintained relatively higher than that of the first battery  252  by means of a discharge for supplying power to the external electronic device. 
     The processor  270  may turn on the voltage divider circuit  264  if the voltage difference between the first battery  252  and the second battery  254  exceeds a reference voltage (e.g., about 100 mV), based on supply of power to the external electronic device. The voltage divider circuit  264 , if turned on by the processor  270 , may alternately turn on a first pair of the first transistor  402  and the third transistor  406  and a second pair of the second transistor  404  and the fourth transistor  408 . 
     If the second pair of transistors (e.g., the second transistor  404  and the fourth transistor  408 ) is turned on at a first point in time, the first capacitor  410  may be electrically connected to the second battery  254  through the second pair of transistors. The first capacitor  410 , if connected to the second battery  254 , may be charged ( 820 ) by a current provided from the second battery  254  having a voltage relatively higher than that of the first battery  252 , as in  FIG. 8B . 
     If the first pair of transistors (e.g., the first transistor  402  and the third transistor  406 ) is turned on at a second point in time, the first capacitor  410  may be electrically connected to the first battery  252  through the first pair of transistors. If the first capacitor  410  is connected to the first battery  252 , energy accumulated by the second battery  254  may be provided to the first battery  252  having a voltage relatively lower than that of the second battery  254 , as in  FIG. 8C , thereby charging ( 830 ) the first battery  252 . As a result, energy accumulated in the first battery  252  and the second battery  254 , which has become unbalanced by the supply of power to the external electronic device (or internal electronic device), may become uniform by means of the voltage divider circuit  264 . 
     According to an embodiment, an electronic device (e.g., the electronic device  101  in  FIG. 1  or the electronic device  201  in  FIG. 2A  and  FIG. 2B ) may include a voltage divider circuit, (e.g., the voltage divider circuit  264  in  FIG. 2B ); a first battery (e.g., the first battery  252  in  FIG. 2B ) electrically connected to a first point of the voltage divider circuit, and a second battery (e.g., the second battery  254  in  FIG. 2B ) connected in series to the first battery. A second point different from the first point of the voltage divider circuit may be electrically connected from a first node on an electric path through which the first battery and the second battery are electrically connected. 
     The electronic device may further include a high-voltage charging circuit the high-voltage charging circuit  320  in  FIG. 3 ) and a low-voltage charging circuit (e.g., the low-voltage charging circuit  330  in  FIG. 3 ). The high-voltage charging circuit may be electrically connected to a second node on a second electric path through which the first battery and the first point of the voltage divider circuit are electrically connected. The low-voltage charging circuit may be electrically connected to a third node electrically connected from the first node through the second point of the voltage divider circuit. 
     The second battery may be charged based on a charging current applied to the first node from the low-voltage charging circuit through the second point of the voltage divider circuit. 
     The first battery and the second battery may be charged based on a charging current applied to the second node from the high-voltage charging circuit. 
     The second battery may supply power to an internal system of the electronic device through the second point of the voltage divider circuit connected to the first node. 
     The voltage divider circuit may include a capacitor (e.g., the first capacitor  410  in  FIG. 4A ) and multiple transistors connected in series. The first transistor (e.g., the first transistor  402  in  FIG. 4A ) among the multiple transistors may be electrically connected between the second node and a fourth node. The second transistor (e.g., the second transistor  404  in  FIG. 4A ) among the multiple transistors may be electrically connected between the fourth node and the second point of the voltage divider circuit. The third transistor (e.g., the third transistor  406  in  FIG. 4A ) among the multiple transistors may be electrically connected between the second point of the voltage divider circuit and a fifth node. The fourth transistor (e.g., the fourth transistor  408  in  FIG. 4A ) among the multiple transistors may be electrically connected between the fifth node and a ground unit. The capacitor may be electrically connected between the fourth node, the third transistor, and the fifth node. 
     A pair of the first transistor and the third transistor and a pair of the second transistor and the fourth transistor may be alternately turned on if the voltage divider circuit is turned on. 
     The capacitor may be electrically connected to the first battery if the pair of the first transistor and the third transistor is turned on, and the capacitor may be electrically connected to the second battery if the pair of the second transistor and the fourth transistor is turned on. 
     The electronic device may further include at least one processor (e.g., the processor  270  in  FIG. 2B ). The at least one processor may control the voltage divider circuit so as to be turned on if a voltage difference between the first battery and the second battery satisfies a designated first condition, and may control the voltage divider circuit so as to be turned off if the voltage difference between the first battery and the second battery does not satisfy the designated first condition. 
     The at least one processor may control at least some of multiple sub-divider circuits included in the voltage divider circuit so as to be turned on if the voltage difference between the first battery and the second battery satisfies a designated second condition in a state in which the voltage divider circuit is turned on, and may adjust a turning-on cycle of the voltage divider circuit if the voltage difference between the first battery and the second battery satisfies a designated third condition in a state in which at least a part of the voltage divider circuit is turned on. 
     The voltage divider circuit may include a first sub-divider circuit (e.g., the third sub-divider circuit  460  in  FIG. 4C ) including a first transistor having an on-resistance configured to have a first value (e.g., about 25 mΩ), and a second sub-divider circuit (e.g., the fourth sub-divider circuit  480  in  FIG. 4C ) including a second transistor having an on-resistance configured to have a second value (e.g., about 10 mΩ. The voltage divider circuit may be configured such that the first sub-divider circuit is turned on if a voltage difference between the first battery and the second battery satisfies a designated third condition, and the second sub-divider circuit is turned on if the voltage difference between the first battery and the second battery does not satisfy the designated third condition. 
     According to an embodiment, an electronic device (e.g., the electronic device  101  in  FIG. 1  or the electronic device  201  in  FIG. 2A  and  FIG. 2B ) may include a first battery, (e.g., the first battery  252  in  FIG. 2B ); a second battery (e.g., the second battery  254  in  FIG. 2B ) connected in series to the first battery, a power management module (e.g., the power management module  220  in  FIG. 2B ) configured to control charging and/or discharging of the first battery and the second battery, and a processor (e.g., the processor  270  in  FIG. 2B ) operatively connected to the power management module. The power management module may include a voltage divider circuit (e.g., the voltage divider circuit  264  in  FIG. 2B ) having a first point connected to the first battery and having a second point, which is different from the first point, connected to a node on an electric path through which the first battery and the second battery are electrically connected. The processor may turn on the voltage divider circuit if a voltage difference between the first battery and the second battery satisfies a designated condition. 
       FIG. 9  is a flowchart for a method of controlling a voltage divider circuit in connection with an electronic device, according to an embodiment. In the following embodiments, respective operations may be performed successively, but are not necessarily performed successively. The order of respective operations may be changed, and at least two operations may be performed in parallel. The electronic device, in this regard, may be the electronic device  101  in  FIG. 1  or the electronic device  201  in  FIG. 2A  and  FIG. 2B . 
     Referring to  FIG. 9 , the electronic device (e.g., the processor  120  in  FIG. 1  or the processor  270  in  FIG. 2B ) may, in operation  901 , identify the voltage of multiple batteries (e.g., the first battery  252  and/or the second battery  254  in  FIG. 2B ) included in the electronic device. The processor  270  may identify the voltage of the first battery  252  and the second battery  254  connected in series, by using a detecting module  266 . The voltage of the first battery  252  and the second battery  254  may be identified periodically, at a designated time, or in response to detecting the occurrence of an event corresponding to voltage identification (e.g., if the amount of consumed current is equal to/larger than a reference value). 
     The electronic device may, in operation  903 , identify whether or not the voltage difference between the batteries (e.g., the first battery  252  and the second battery  254 ) exceeds a reference voltage (e.g., about 100 mV). The processor  270  may identify whether or not the voltage difference between the first battery  252  and the second battery  254 , which has been identified through the detecting module  266 , exceeds the reference voltage. 
     If the voltage difference between the batteries exceeds the reference voltage (“Yes” in operation  903 ), the electronic device may turn on a voltage divider circuit in operation  905 . If the voltage difference between the first battery  252  and the second battery  254  exceeds the reference voltage, the processor  270  may turn on the voltage divider circuit  264  for balancing the batteries. The voltage divider circuit  264 , if turned on, may alternately turn on the first transistor  402  the third transistor  406 , the second transistor  404 , and the fourth transistor  408 , as in  FIG. 4A , such that the energy accumulated in the first battery  252  and the second battery  254  becomes uniform. 
     If the voltage difference between the batteries is equal to/lower than the reference voltage (“No” in operation  903 ), the electronic device may turn off the voltage divider circuit  264  in operation  907 . If the voltage difference between the first battery  252  and the second battery  254  is equal to/lower than the reference voltage, the processor  270  may turn off the voltage divider circuit  264  in order to reduce current consumption. 
       FIG. 10  is a flowchart for a method of controlling a voltage divider circuit based on a voltage difference between batteries in connection with an electronic device, according to an embodiment. In the following embodiments, respective operations may be performed successively, but are not necessarily performed successively. The order of respective operations may be changed, and at least two operations may be performed in parallel. The electronic device, in this regard, may be the electronic device  101  in  FIG. 1  or the electronic device  201  in  FIG. 2A  and  FIG. 2B . 
     Referring to  FIG. 10 , the electronic device (e.g., the processor  120  in  FIG. 1  or the processor  270  in  FIG. 2B ) may, in operation  1001 , identify the voltage of multiple batteries (e.g., the first battery  252  and/or the second battery  254  in  FIG. 2B ) included in the electronic device. A detecting module  266  may monitor the voltage of the first battery  252  and the second battery  254  periodically, at a designated time, or in response to detecting the occurrence of an event corresponding to voltage identification. 
     The electronic device may, in operation  1003 , identify whether or not the voltage difference between the batteries (e.g., the first battery  252  and the second battery  254 ) exceeds a first reference voltage (e.g., about 100 mV). The processor  270  may identify whether or not the voltage difference between the first battery  252  and the second battery  254 , which has been identified through the detecting module  266 , exceeds the reference voltage. 
     If the voltage difference between the batteries exceeds the first reference voltage (“Yes” in operation  1003 ), the electronic device may turn on a voltage divider circuit (e.g., the voltage divider circuit  264  in  FIG. 2B ) in operation  1005 . If the voltage difference between the first battery  252  and the second battery  254  exceeds the first reference voltage, the processor  270  may turn on the voltage divider circuit  264  such that the voltage divider circuit  264  operates in a first mode. The voltage divider circuit  264 , if turned on in the first mode, may turn on both the first sub-divider circuit  420  and the second subdivider circuit  440 , as in  FIG. 4B , thereby balancing the first battery  252  and the second battery  254 . If the first sub-divider circuit  420  operates in the first mode, the first pair of the fifth transistor  422  and the seventh transistor  426  and the second pair of the sixth transistor  424  and the eighth transistor  428  may be alternately turned on. In this case, the second capacitor  430  may be connected to the first battery  252  or the second battery  254 , based on the turned-on transistors (e.g., the first pair or the second pair), such that energy accumulated in the first battery  252  and the second battery  254  in an unbalanced manner is uniformly adjusted. If the second sub-divider circuit  440  operates in the first mode, the first pair of the ninth transistor  442  and the eleventh transistor  446  and the second pair of the tenth transistor  444  and the twelfth transistor  448  may be alternately turned on. In this case, the third capacitor  450  may be connected to the first battery  252  or the second battery  254 , based on the turned-on transistors (e.g., the first pair or the second pair), such that energy accumulated in the first battery  252  and the second battery  254  in an unbalanced manner is uniformly adjusted. The first sub-divider circuit  420  and the second sub-divider circuit  440  may be synchronized in the first mode. 
     The electronic device may identify, in operation  1007 , whether or not the voltage difference between the batteries has dropped below a second reference voltage (e.g., about 60 mV), based on turning-on of the voltage divider circuit. The processor  270  may identify whether or not the voltage difference between the first battery  252  and the second battery  254  has dropped below the second reference voltage by means of the voltage divider circuit  264  operating in the first mode. 
     If the voltage difference between the batteries is equal to/higher than the second reference voltage (e.g., about 60 mV) (e.g., “No” in operation  1007 ), the electronic device may maintain driving of the voltage divider circuit in the first mode in operation  1005 . 
     If the voltage difference between the batteries has dropped below the second reference voltage (e.g., “Yes” in operation  1007 ), the electronic device may turn on at least a part of the voltage divider circuit in operation  1009 . The processor  270  may turn on a part of the voltage divider circuit  264  such that the voltage divider circuit  264  operates in the second mode. If the voltage divider circuit  264  includes a first sub-divider circuit  420  and a second sub-divider circuit  440  as in  FIG. 4B , the voltage divider circuit  264  may turn on one of the first sub-divider circuit  420  or the second sub-divider circuit  440 , thereby balancing the first battery  252  and the second battery  254 . If the first sub-divider circuit  420  has been turned on to operate in the second mode, the first pair of the fifth transistor  422  and the seventh transistor  426  and the second pair of the sixth transistor  424  and the eighth transistor  428  may be alternately turned on. 
     The electronic device may identify, in operation  1011 , whether or not the voltage difference between the batteries has dropped below a third reference voltage (e.g., about 20 mV), based on turning-on of at least a part of the voltage divider circuit. The processor  270  may identify whether or not the voltage difference between the first battery  252  and the second battery  254  has dropped below the third reference voltage by means of the voltage divider circuit  264  operating in the second mode. 
     If the voltage difference between the batteries is equal to/higher than the third reference voltage (e.g., about 20 mV) (e.g., “No” in operation  1011 ), the electronic device may identify in operation  1013 , whether or not the voltage difference between the batteries exceeds a fourth reference voltage (e.g., about 80 mV). 
     If the voltage difference between the batteries is equal to/higher than the third reference voltage (e.g., “No” in operation  1011 ) and equal to/lower than the fourth reference voltage (e.g., “No” in operation  1013 ), the electronic device may maintain the driving of the voltage divider circuit in the second mode in operation  1009 . 
     If the voltage difference between the batteries (exceeds the fourth reference voltage (e.g., “Yes” in operation  1013 ), the electronic device may switch the operating mode of the voltage divider circuit to the first mode in operation  1005 . The processor  270  may turn on both the first sub-divider circuit  420  and the second sub-divider circuit  440 , thereby balancing the first battery  252  and the second battery  254 . 
     If the voltage difference between the batteries drops below the third reference voltage (e.g., “Yes” in operation  1011 ), the electronic device may control the cycle at which the voltage divider circuit is turned on, in operation  1015 . The processor  270  may configure the cycle at which the voltage divider circuit  264  is turned on such that the voltage divider circuit  264  operates in the third mode. The voltage divider circuit  264  may be periodically turned on, based on the turning-on cycle, thereby balancing the first battery  252  and the second battery  254 . If the turning-on cycle of the voltage divider circuit  264  arrives, the first pair of the fifth transistor  422  and the seventh transistor  426  and the second pair of the sixth transistor  424  and the eighth transistor  428  may be alternately turned on at a first cycle, during the turning-on interval. If a turning-off interval of the voltage divider circuit  264  arrives, the same may be turned off, thereby limiting the driving of the fifth transistor  422 , the sixth transistor  424 , the seventh transistor  426 , and eighth transistor  428 . 
     The electronic device may identify whether or not a reference time elapses after the turning-on cycle of the voltage divider circuit is controlled, in operation  1017 . The processor  270  may identify whether or not driving of a tinier expires, the timer being driven at a point in time at which the voltage divider circuit  264  switches to the third mode. 
     If the reference time has not elapsed (e.g., “No” in operation  1017 ), the electronic device may identify, in operation  1019 , whether or not the voltage difference between the batteries exceeds a fifth reference voltage (e.g., about 40 mV). 
     If the voltage difference between the batteries is equal to/lower than the fifth reference voltage (e.g., “No” in operation  1019 ), the electronic device may maintain the driving of the voltage divider circuit in the third mode in operation  1015 . 
     If the voltage difference between the batteries exceeds the fifth reference voltage (e.g., “Yes” in operation  1019 ), the electronic device may switch the operating mode of the voltage divider circuit to the second mode in operation  1009 . The processor  270  may turn on one of the first sub-divider circuit  420  or the second sub-divider circuit  440 , thereby balancing the first battery  252  and the second battery  254 . 
     If the reference time has elapsed (e.g., “Yes” in operation  1017 ), the electronic device may turn off the voltage divider circuit in operation  1021 . The processor  270  may determine that energy accumulated in the first battery  252  and the second battery  254  is uniform if the voltage difference between the first battery  252  and the second battery  254  remains below the third reference voltage (e.g., about 20 mV) during the reference time. Accordingly, the processor  270  may turn off the voltage divider circuit  264  in order to reduce current consumption. 
     If the voltage divider circuit  264  switches to the third mode, the electronic device may control the switching cycle of a pair of transistors. If the first sub-divider circuit  420  in  FIG. 4B  is turned on such that the voltage divider circuit  264  operates in the second mode, the first pair of the fifth transistor  422  and the seventh transistor  426  and the second pair of the sixth transistor  424  and the eighth transistor  428  may be alternately turned on at a first cycle. If the voltage divider circuit  264  switches to the third mode, the first pair of the fifth transistor  422  and the seventh transistor  426  and the second pair of the sixth transistor  424  and the eighth transistor  428  may be alternately turned on at a second cycle which is configured to be relatively longer than the first cycle. 
       FIG. 11  is a flowchart for a method of determining the operating mode of a voltage divider circuit based on a voltage difference between batteries in connection with an electronic device, according to an embodiment. In the following embodiments, respective operations may be performed successively, but are not necessarily performed successively. The order of respective operations may be changed, and at least two operations may be performed in parallel. The electronic device, in this regard, may be the electronic device  101  in  FIG. 1  or the electronic device  201  in  FIG. 2A  and  FIG. 2B . 
     Referring to  FIG. 11 , the electronic device (e.g., the processor  120  in  FIG. 1  or the processor  270  in  FIG. 2B ) may identify the voltage of each of multiple batteries first battery  252  and/or a second battery  254 ) included in the electronic device in operation  1101 . The processor  270  may identify the voltage of the first battery  252  and the second battery  254 , by using a detecting module  266 , periodically, at a designated time, or in response to detecting the occurrence of an event corresponding to voltage identification. 
     The electronic device may identify, in operation  1103 , whether or not the voltage difference between the batteries (e.g., the first battery  252  and the second battery  254 ) exceeds a reference voltage (e.g., about 20 mV). The processor  270  may identify whether or not the voltage difference between the first battery  252  and the second battery  254 , which has been identified through the detecting module  266 , exceeds the reference voltage. 
     If the voltage difference between the first battery  252  and the second battery  254  exceeds the reference voltage (e.g., “Yes” in operation  1103 ), the electronic device may identify, in operation  1105 , the operating mode of the voltage divider circuit based on the voltage difference between the batteries. If the voltage difference between the first battery  252  and the second battery  254  exceeds a first reference voltage (e.g., about 100 mV), the processor  270  may determine that the operating mode of the voltage divider circuit  264  is a first mode in which the voltage divider circuit  264  is entirely turned on. If the voltage difference between the first battery  252  and the second battery  254  is equal to/lower than the first reference voltage (e.g., about 100 mV) and exceeds a second reference voltage (e.g., about 60 mV), the processor  270  may determine that the operating mode of the voltage divider circuit  264  is a second mode in which at least a part of the voltage divider circuit  264  is turned on. If the voltage difference between the first battery  252  and the second battery  254  is equal to/lower than the second reference voltage (e.g., about 60 mV) and exceeds a third reference voltage (e.g., about 20 mV), the processor  270  may determine that the operating mode of the voltage divider circuit  264  is a third mode in which the turning-on cycle of the voltage divider circuit  264  is controlled. 
     The electronic device may drive the voltage divider circuit based on the operating mode of the voltage divider circuit corresponding to the voltage difference between the batteries in operation  1107 . If the voltage divider circuit  264  includes multiple sub-divider circuits  420  and  440  as in  FIG. 4B , the multiple sub-divider circuits  420  and  440  may all be turned on based on a first mode. If the voltage divider circuit  264  includes multiple sub-divider circuits  420  and  440  as in  FIG. 4B , one of the first sub-divider circuit  420  or the second sub-divider circuit  440  may be turned on based on a second mode. If the voltage divider circuit  264  includes multiple sub-divider circuits  420  and  440  as in  FIG. 4B , the turning-on cycle of a sub-divider circuit  430  or  440 , which has been turned on among the first sub-divider circuit  420  and the second sub-divider circuit  440 , may be configured based on a third mode. 
     If the voltage difference between the batteries is equal to/lower than a reference voltage (e.g., “No” in operation  1103 ), the electronic device may turn off the voltage divider circuit in operation  1109 . If the voltage difference between the first battery  252  and the second battery  254  is equal to/lower than the reference voltage (20 mV), the processor  270  may determine that energy is evenly accumulated in the first battery  252  and the second battery  254 . Accordingly, the processor  270  may control the voltage divider circuit  264  such that the voltage divider circuit  264  is turned off, in order to reduce current consumption. 
     The electronic device may drive the voltage divider circuit  264 , which is configured as in  FIG. 4A , in an operating mode corresponding to the voltage difference between the first battery  252  and the second battery  254 . If the voltage divider circuit  264  is configured as in  FIG. 4A , the first transistor  402 , the second transistor  404 , the third transistor  406 , and the fourth transistor  408  may be turned on based on a first mode. The first pair of the first transistor  402  and the third transistor  406  and the second pair of the second transistor  404  and the fourth transistor  408  may be alternately turned on at a first cycle. If the voltage divider circuit  264  is configured as in  FIG. 4A , the switching cycle of the pair of transistors turned on based on a second mode may be changed to be relatively longer. The first pair of the first transistor  402  and the third transistor  406  and the second pair of the second transistor  404  and the fourth transistor  408  may be alternately turned on at a second cycle configured to be relatively longer than the first cycle. If the voltage divider circuit  264  is configured as in  FIG. 4A , the turning-on cycle of the voltage divider circuit  264  may be configured based on a third mode. If a turning-on cycle of the voltage divider circuit  264  arrives, the first pair of the first transistor  402  and the third transistor  406  and the second pair of the second transistor  404  and the fourth transistor  408  may be alternately turned on at a second cycle during a turning-on interval. If a turning-off interval of the voltage divider circuit  264  arrives, the same may be turned off, thereby limiting the driving of the first transistor  402 , the second transistor  404 , the third transistor  406 , and the fourth transistor  408 . The turning-on cycle of the voltage divider circuit  264  may include a cycle at which the voltage divider circuit  264  switches to a turned-on state or a turned-off state, and the second cycle (or first cycle) may include a switching cycle of a pair of transistors (e.g., first or second pair) which is turned on inside the voltage divider circuit  264  if the voltage divider circuit  264  is in a turned-on state. 
       FIG. 12  is a flowchart for a method of configuring an on-resistance of a transistor in connection with an electronic device, according to an embodiment. In the following embodiments, respective operations may be performed successively, but are not necessarily performed successively. The order of respective operations may be changed, and at least two operations may be performed in parallel. The electronic device, in this regard, may be the electronic device  101  in  FIG. 1  or the electronic device  201  in  FIG. 2A  and  FIG. 2B . Hereinafter, at least some configurations in  FIG. 12  may be described with reference to  FIG. 13A ,  FIG. 13B , and  FIG. 14 .  FIG. 13A  is a graph illustrating a change in the amount of current with regard to the on-resistance of a transistor, according to an embodiment.  FIG. 13B  is a graph illustrating a change in the amount of current with regard to the on-resistance of a transistor, according to an embodiment.  FIG. 14  is a graph illustrating cell balancing with regard to the on-resistance of a transistor, according to an embodiment. 
     Referring to  FIG. 12 , the electronic device (e.g., the processor  120  in  FIG. 1  or the processor or  270  in  FIG. 2B ) may identify, in operation  1201 , whether or not a voltage divider circuit (e.g., the voltage divider circuit  264  in  FIG. 2B ) has been turned on, The processor  270  may identify whether or not the voltage divider circuit  264  has been turned on, based on the voltage difference between the first battery  252  and the second battery  254 . 
     If the voltage divider circuit is in an turned-off state (e.g., “No” in operation  1201 ), the electronic device may determine that no ripple current (or inrush current) has occurred. 
     If the voltage divider circuit is in an turned-on state (e.g., “Yes: in operation  1201 ), the electronic device may identify, in operation  1203 , whether or not the voltage difference between the first battery  252  and the second battery  254  exceeds a sixth reference voltage (e.g., about 200 mV). 
     If the voltage difference between the batteries exceeds the reference voltage (e.g., about 200 mV) (e.g., “Yes” in operation  1203 ), the electronic device may determine that the on-resistance of a transistor included in the voltage divider circuit has a first value (e.g., about 25 mΩ) in operation  1205 . A voltage difference may exist between the first battery  252  and the second battery  254  if the voltage divider circuit  264  is turned on and thus starts balancing. The peak magnitude (i CP_peak ) of the current flowing through the voltage divider circuit  264  may be defined as in Equation 1 below: 
         i   CP_peak =( C   C1   −V   2 )/2* R   S )   (1)
 
     In Equation (1), V C1  refers to the voltage of the first battery  252 , V C2  refers to the voltage of the second battery  254 , and R S  may include the on-resistance of the transistor included in the voltage divider circuit  264 . Assuming that V C1  is 4.1 V 2  is 3.6V, the voltage difference between the first battery  252  and the second battery  254  is 500 mV, and R S  is 10 mΩ, the peak value of the magnitude (i CP ) of the current flowing through the voltage divider circuit  264  may be about 25 A ( 1300 ), as in  FIG. 13A . Assuming that V C1  is 4.1V, V C2  is 3.6V, the voltage difference between the first battery  252  and the second battery  254  is 500 mV, and R S  is 25 mΩ, the peak value of the magnitude (i CP ) of the current flowing through the voltage divider circuit  264  may be about 10 A ( 1302 ), as in  FIG. 13A . Accordingly, if the voltage difference between the first battery  252  and the second battery  254  exceeds the reference value (e.g., about 200 mV), the processor  270  may determine that the on-resistance of the voltage divider circuit  264  has a first value (e.g., about 25 mΩ), in order to prevent an overcurrent caused by balancing. If the voltage divider circuit  264  includes sub-divider circuits  460  and  480  configured to have different on-resistances, as in  FIG. 4C , a sub-divider circuit (e.g., a third sub-divider circuit  460 ) configured to have a first value may be used to balance the first battery  252  and the second battery  254 . The horizontal axis in  FIG. 13A  may denote time, and the vertical axis may denote the magnitude of the current (A). 
     If the voltage difference between the batteries is equal to/lower than the reference voltage (e.g., about 200 mV) (e.g., “Yes” in operation  1203 ), the electronic device may determine that the on-resistance of the transistor included in the voltage divider circuit has a second value (e.g., about 10 mΩ) in operation  1207 . The time necessary to fully balance the batteries and the conversion loss for balancing the batteries may increase in proportion to the on-resistance of the transistor. The time  1312  necessary to fully balance the batteries when the on-resistance of the transistor is configured to have a first value e.g., about 25 mΩ) may increase than the time  1310  necessary to fully balance the batteries when the on-resistance of the transistor is configured to have a second value (e.g., about 10 mΩ), as in  FIG. 13B . Accordingly, if the voltage difference between the first battery  252  and the second battery  254  is equal to/lower than the reference voltage, the processor  270  may determine that the on-resistance of the voltage divider circuit  264  has a second value (e.g., about 10 mΩ) in order to improve the battery balancing efficiency (e.g., to shorten the cell balancing time). If the voltage divider circuit  264  includes sub-divider circuits  460  and  480  configured to have different on-resistances, as in  FIG. 4C , a sub-divider circuit configured to have a second value may be used to balance the first battery  252  and the second battery  254 . The horizontal axis in  FIG. 13B  may denote time, and the vertical axis may denote the magnitude of the voltage (V). 
     The electronic device  201  may adaptively configure the on-resistance of the voltage divider circuit  264  based on the voltage difference between the first battery  252  and the second battery  254 , similarly to steps  1201  to  1207  in  FIG. 12 . In this case, the time necessary to fully balance the batteries may be relatively shorter than in the case in which the on-resistance of the voltage divider circuit  264  is maintained at a first value. The processor  270  may change the on-resistance of the transistor included in the voltage divider circuit  264  from the first value to the second value at a first point in time  1412 , based on the voltage difference between cells, as in  FIG. 14 . The time  1410  necessary to fully balance the batteries in the case in which the on-resistance is adaptively determined based on the voltage difference between the first battery  252  and the second battery  254  may be relatively shorter than the time  1400  necessary to fully balance the batteries in the case in which the on-resistance is fixed at the first value. The horizontal axis in  FIG. 14  may denote time, and the vertical axis may denote the magnitude of the voltage (V). 
     According to an embodiment, a method for operating an electronic device (e.g., the electronic device in  FIG. 1  or the electronic device  201  in  FIG. 2A  and  FIG. 2B ) may include the steps of identifying voltages of a first battery (e.g., the first battery  252  in  FIG. 2B ) and a second battery (e.g., the second battery  251  in  FIG. 2B ) connected in series and turning on a voltage divider circuit (e.g., the voltage divider circuit  264  in  FIG. 2B ) if a voltage difference between the first battery and the second battery satisfies a designated first condition, the voltage divider circuit having a first point connected to the first battery and having a second point, which is different from the first point, connected to a first node on an electric path through which the first battery and the second battery are electrically connected. 
     The method may further include alternately turning on a pair of a first transistor and a third transistor and a pair of a second transistor and a fourth transistor, which are included in the voltage divider circuit, if the voltage divider circuit is turned on, the voltage divider circuit including multiple transistors connected in series and a capacitor connected to at least some of the multiple transistors. 
     The method may further include connecting the first battery and the capacitor of the voltage divider circuit if the pair of the first transistor and the third transistor is turned on, and connecting the second battery and the capacitor of the voltage divider circuit if the pair of the second transistor and the fourth transistor is turned on. If the capacitor is connected to one battery having a relatively high voltage between the first battery and the second battery, the capacitor may be charged based on a current provided from the one battery. If the capacitor is connected to the other battery having a relatively low voltage, the capacitor may discharge a current to the other battery. 
     The method may further include identifying voltages of the first battery and the second battery in a state in which the voltage divider circuit is turned on, and turning on at least a part of the voltage divider circuit if a voltage difference between the first battery and the second battery satisfies a designated second condition. 
     The step of turning on at least a part may include an operation of turning on at least one of multiple sub-divider circuits included in the voltage divider circuit, 
     The method may further include identifying voltages of the first battery and the second battery in a state in which at least a part of the voltage divider circuit is turned on, and turning on multiple sub-divider circuits included in the voltage divider circuit if the voltage difference between the first battery and the second battery satisfies a designated third condition different from the designated second condition. 
     The method may further include identifying voltages of the first battery and the second battery in a state in which at least a part of the voltage divider circuit is turned on, and adjusting a turning-on cycle of the voltage divider circuit if the voltage difference between the first battery and the second battery satisfies a designated fourth condition. 
     The method may further include identifying voltages of the first battery and the second battery in a state in which the turning-on cycle of the voltage divider circuit is controlled, and turning off the voltage divider circuit if the voltage difference between the first battery and the second battery continuously satisfies the third condition during a reference time. 
     An electronic device may connect a first battery (e.g., a pack of batteries or a cell of batteries) connected in series and a first point of a voltage divider circuit, and may connect a first node on an electric path, which connects the first battery and a second battery (e.g., a pack of batteries or a cell of batteries), and a second point of the voltage divider circuit, thereby charging/discharging and balancing batteries. 
     An electronic device has a simplified circuit for controlling the charging/discharging and balancing of multiple batteries connected in series (e.g., a pack of batteries or a cell of batteries), thereby reducing the mounting space of the electronic device, and the capacity and/or type of batteries included in the electronic device may be variously applied. 
     An electronic device may have a reduced range of charging/discharging power of batteries controlled by a voltage divider circuit, thereby substantially reducing the size and cost of circuits constituting the voltage divider circuit. 
     While the disclosure has been shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the disclosure. Therefore, the scope of the disclosure should not be defined as being limited to the embodiments, but should be defined by the appended claims and equivalents thereof.