An automatic switching battery source circuit and a portable electronic device

Abstract

The application discloses a kind of portable electronic equipment battery charging and discharging technical field's automatic switching battery source circuit and portable electronic equipment, including main control unit, path selection unit, charging management unit, shared power distribution unit, power input unit and at least two battery sources, the path selection unit is used to control the charging and discharging selection of battery source, the charging management unit includes at least two independently controllable charging units, each charging unit shares a power topology BOOST-BUCK, for narrow voltage direct-current power path management and multiple-unit synchronous boost battery charger control, the shared power distribution unit is used to dynamically allocate the input power and current of charging unit in charging management unit, the above scheme solves the problems of high hardware cost, cannot be small size and low charging efficiency in prior art, achieves the technical effects of reducing cost, reducing size and improving charging efficiency.

Description

Technical Field

[0001] This utility model relates to the field of battery charging and discharging technology for portable electronic devices, specifically an automatic battery power switching circuit and a portable electronic device. Background Technology

[0002] With the increasing power and expanding usage scenarios of portable electronic devices such as smartphones, tablets, laptops, drones, and power tools, single-battery power supply can no longer meet their comprehensive requirements for battery life, peak power output, and safety. Multi-battery systems have emerged to address this need. Multiple batteries can be connected in series to increase operating voltage and enhance power output, meeting the higher demands for discharge capacity and performance in high-power applications. They can also be connected in parallel to increase total capacity, satisfying the device's higher requirements for battery life. Multi-battery systems also offer greater flexibility in adapting to complex internal space layouts, solving the problem of some devices being unable to accommodate the size of a single battery. In applications with extremely high reliability requirements, multi-battery systems can also provide redundancy; when one battery fails, the others can maintain basic device functions to a certain extent, ensuring the continuity of critical tasks and thus improving overall system safety. Multi-battery systems also provide new ways to achieve fast charging, allowing multiple batteries to be charged in a time-sharing or simultaneous manner.

[0003] Existing technical solutions include various approaches, such as dual-battery charging solutions based on charging management chips. These typically employ an integrated dual-battery charging management IC or a combination of multiple single-battery charging ICs. The integrated dual-battery charging IC solution may have a higher chip cost than a single single-battery IC, and if the chip fails, both charging channels are affected. The solution combining multiple single-battery charging ICs has relatively higher hardware costs, potentially lower charging efficiency, and a larger overall size. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an automatic battery switching circuit and a portable electronic device to solve the problems arising from the two existing solutions.

[0005] To achieve the above objectives, this utility model provides the following technical solution: An automatic battery power switching circuit includes a main control unit, a path selection unit, a charging management unit, a shared power distribution unit, a power input unit, and at least two battery power sources. The main control unit is used for overall charging management and decision-making. The path selection unit is electrically connected to the main control unit and the battery power sources to control the charging and discharging selection of the battery power sources. The charging management unit is communicatively connected to the main control unit and electrically connected to the path selection unit and the battery power sources. It includes at least two independently controllable charging units, each of which shares a single power topology BOOST-BUCK for narrow-voltage DC power path management and control of multi-unit synchronous boost battery chargers. The shared power distribution unit is connected between the power input unit and the charging management unit to dynamically allocate the input power and current of the charging units in the charging management unit. The power input unit is electrically connected to the main control unit, the path selection unit, and the charging management unit and provides operating voltage to each unit.

[0006] Preferably, the main control unit uses a microcontroller, and the microcontroller uses the 32-bit GD32F30x series.

[0007] Preferably, the charging management unit uses SYV976.

[0008] Preferably, the path selection unit is a dual-battery interface module, using MAX1538.

[0009] Preferably, the MAX1538 is electrically connected to the input / output port of the main control unit via three control lines: charge enable (CHRG), battery select (BATSEL), and relearn (RELRN), for controlling the charging and discharging selection of the battery source.

[0010] Preferably, the MAX1538 is also connected to the input / output port of the main control unit through selector status output pins OUT1, OUT2 and OUT3, for outputting the system's power source, charging status and error flag.

[0011] Preferably, it also includes a display unit, which is electrically connected to the main control unit and is used to display the real-time status of the battery, charging mode, and fault information.

[0012] Preferably, the shared power distribution unit includes a synchronous step-up / step-down power switch, wherein the synchronous step-up / step-down power switch is a TDM3478.

[0013] Preferably, the battery source has a built-in BMS battery management module, which is used for current monitoring, internal resistance estimation and / or voltage monitoring, and temperature monitoring.

[0014] Based on the same inventive concept, this application also uses the following solution: A portable electronic device comprising the aforementioned automatic battery switching circuit.

[0015] This application proposes an automatic battery power switching circuit and a portable electronic device. Based on the latest power selector and a separate charging chip, it controls the automatic switching charging of dual batteries by reading battery SOC data. It is small in size, low in hardware cost, and achieves dual battery charging and system power supply management in a relatively short development cycle. This solution only uses a separate battery charging management chip, which can be used for both single and dual batteries. The path selection prioritizes external power sources such as adapters to power the system. The layout is simple, the hardware cost is less than half that of the prior art, the size can be made very small, and the charging efficiency is improved by 50%. Attached Figure Description

[0016] Figure 1 This is a schematic block diagram of an embodiment of the automatic battery power switching circuit of this application; Figure 2 Example of peripheral circuitry for an embodiment of the automatic battery power switching circuit charging management unit of this application; Figure 3 This is an example of the peripheral circuit of an embodiment of the automatic battery power circuit path selection unit of this application; Among them, 1-power adapter, 2-charging management unit, 21-synchronous step-up power switch, 3-path selection unit, 4-main control unit, 5-first battery pack, 6-second battery pack, and 7-display unit. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0018] This embodiment provides a technical solution: an automatic battery power switching circuit according to this application includes a power input unit. The power input unit can accept AC 100-240V DC voltage converted to DC voltage, or DC 5V / 9V / 12V / 20V and other USB PD voltages, and then convert them into the operating voltages required by the various unit chips of the system, such as 3.3V, 5V, etc. This embodiment accepts power adapter 1 as input, and the maximum voltage output of power adapter 1 is DC≤28V.

[0019] The automatic battery power switching circuit in this embodiment includes a main control unit 4, which is the core processor responsible for the overall management, data processing, decision-making, and command issuance of the entire charging system. It has a built-in or external storage unit for storing battery characteristic parameters, charging curve models, user settings preferences, and charging history data. It also has communication interfaces such as UART / I2C / SPI. In this embodiment, the main control unit 4 uses a microprocessor; the 32-bit GD32F30x series uses the GD32F303VET6. CHRG_OK is the adapter connection detection pin.

[0020] The path selection unit 3 is a dual-battery interface module using a MAX1538. This module provides two independent battery connection ports to connect the first battery pack 5 and the second battery pack 6, supporting the connection of different types of rechargeable batteries, such as lithium-ion, lithium polymer, and lithium iron phosphate, as well as batteries with different voltages and capacities. In this embodiment, these correspond to A and B in the block diagram and peripheral circuit. Each interface includes overcurrent protection, overvoltage protection, and reverse connection protection circuits. The path selection unit 3 also integrates a battery identification circuit, which can automatically identify the type, nominal voltage, nominal capacity, and other information of the connected battery by reading the internal BMS data of the battery.

[0021] In this embodiment, the MINVA and MINVB pins of the MAX538 can be set to set the minimum protection voltage for the two batteries for undervoltage protection. When the battery voltage is detected to be too low, such as below 11.34V, the battery discharge is prohibited. When the battery voltage drops to 11.57V, the output undervoltage protection is automatically turned off, and the voltage is 12.08V after shutdown.

[0022] The charging management unit 2 is used for narrow-voltage DC power path management and multi-unit synchronous boost battery charger control. It includes at least two independently controllable charging units, each sharing a single power topology BOOST-BUCK, which can convert the input DC voltage, such as the voltage from an AC-DC adapter or USB PD, into a charging voltage and current suitable for the corresponding battery. Each charging unit is independently controlled by the digital control signal of the main control unit 4, allowing for precise adjustment of the output voltage and current.

[0023] In this embodiment, the charging management unit 2 uses the SYV976 from Xilijie. This unit is a multi-unit synchronous boost battery charger controller with NVDC power path management, including charging unit A and charging unit B, each corresponding to two battery interfaces. It supports charging up to four battery cells and communicates with the main control unit 4 via I2C. The two battery groups are connected to the main control unit 4 via the I2C SMBUS bus. The path selection unit 3 uses the MAX1538, which supports channel selection for two batteries and adapters. It mainly consists of three control lines: charging enable CHRG, battery selection BATSEL, and relearning RELRN, which are electrically connected to the input / output ports of the main control unit 4. The logic processing is performed by the high and low levels of the digital input / output ports of the main control unit 4. During operation, it is in charging mode. When the adapter is inserted, the adapter is prioritized to power the system, and then battery group A is charged through the BATACH pin of the charging management unit. The charging management unit 2 and the main control unit 4 dynamically adjust the charging current value based on the real-time data of the battery level. When battery group A is fully charged, the CHRG, RELRN, and BATSEL pins are set to 1, 0, and 1 respectively, and the external MOSFET switch switches to charge battery group B. The two battery groups take turns sharing the charging management unit to save one charging management unit. The MAX1538 is also connected to the input / output port of the main control unit 4 through selector status output pins OUT1, OUT2, and OUT3 to output the system's power source, charging status, and error flags. The truth table and meaning of CHRG, RELRN, BATSEL, OUT1, OUT2, and OUT3 can be found in the chip's datasheet.

[0024] The shared power distribution unit described in this solution is connected between the power input unit and the charging management unit 2. It consists of components such as a synchronous step-up power switch 21, inductors, and capacitors. Under the control of the main control unit 4, it realizes the dynamic distribution of the input power / current of the charging unit A and the charging unit B. In this embodiment, the synchronous step-up power switch 21 is a TDM3478.

[0025] This embodiment of the solution also includes a display unit 7, which is electrically connected to the main control unit 4 and is used to display the real-time status, charging mode, and fault information of the battery. The display unit 7 can use an LCD screen or LED indicator to display the real-time status of the dual batteries, such as charging progress (SOC), voltage, current, temperature, and health status (SOH), as well as the charging mode and fault information.

[0026] In this embodiment, there are two battery sources: a first battery pack 5 and a second battery pack 6. Both the first battery pack 5 and the second battery pack 6 have a built-in BMS battery management module. The BMS battery management module is used for current monitoring, internal resistance estimation and / or voltage monitoring, and temperature monitoring. The first battery pack 5 and the second battery pack 6 support communication with the main control unit 4 via SMBUS bus, transmitting the monitoring data to the main control unit 4 in real time. Current monitoring can measure the charging current and / or (if the battery is supplying power to the outside while charging) the discharging current. Temperature monitoring monitors the battery temperature through NTC thermistors or thermocouples attached near the battery interface or on the battery surface. Voltage monitoring can accurately measure the battery terminal voltage and the voltage of individual cells. Internal resistance estimation estimates the battery internal resistance by combining the AC injection method or the DC discharge method with voltage and current changes, assisting in determining the battery's state of health (SOH).

[0027] This embodiment also includes a safety protection module, an information input unit, and an alarm unit. Under the unified coordination of the main control unit 4, and in conjunction with data from the battery status monitoring module, multiple safety protections are implemented, such as overvoltage protection (OVP), undervoltage protection (UVP), overcurrent protection (OCP), short circuit protection (SCP), and overtemperature protection (OTP). When any battery source experiences an abnormal state, the main control unit 4 can immediately cut off the output of the corresponding charging unit or the input of the entire system, and issue an alarm through the display unit 7 or the alarm unit. The information input unit can be used to allow the user to select which battery source to charge first or to relearn the battery, etc.

[0028] When this embodiment is used, it may include the following stages: Initialization and Battery Identification Phase: The system performs a power-on self-test and initializes each unit. It checks whether a battery power source is connected to Battery A and Battery B interfaces. If a battery power source is connected, the battery identification circuit reads or estimates information such as battery type, nominal voltage, and nominal capacity, and matches this information with stored battery characteristic parameters.

[0029] During the charging strategy selection and parameter configuration phase: The main control unit 4, based on the charging mode or default strategy selected by the user through the information input unit, such as "Priority A Mode," "Priority B Mode," or "Learning Mode," and combined with the identified battery source information, calls up the corresponding charging channel and parameters. For example, in "Priority A Mode," more power is allocated to battery A to quickly charge it before fully charging battery B.

[0030] Dynamic Charging and Power Allocation Stage: Real-time Monitoring: The BMS battery management module continuously collects data such as voltage, current, and temperature of the two batteries and sends it to the main control unit 4. State Estimation: Based on the monitoring data, the main control unit displays the state of charge (SOC) and state of health (SOH) of the two batteries. Intelligent Adjustment: The main control module dynamically adjusts the target voltage and current of charging unit A and charging unit B based on the SOC, SOH, temperature, current charging stage (pre-charge, constant current, constant voltage), and available power of the external power supply. Pre-charge Stage: If the battery voltage is too low, a small current is used for pre-charging to activate the battery power source. Constant Current Stage: After the battery voltage recovers, the constant current fast charging stage begins, and the current is allocated according to the strategy. For example, if the SOC of the first battery pack 5 is low and the temperature is normal, more current can be allocated to the first battery pack 5; if the temperature of a battery is too high, its charging current is reduced. Constant Voltage Stage: When the battery voltage reaches the set threshold, the constant voltage stage begins, and the current gradually decreases. Power Allocation: The main control unit 4 controls the shared power allocation module to ensure that the total power of the two charging units does not exceed the rated output power of the external power supply, while maximizing charging efficiency. For example, if the external power supply is 100W and the first battery pack 5 requires 16.8V / 3.5A, the total demand of 60W < 100W is allowed; if the demand exceeds this, it will be reduced proportionally or according to a strategy.

[0031] Balancing and Protection Phase: Battery Balancing: If a significant difference in SOC is detected between the two batteries or voltage imbalance is detected between individual batteries (for the battery pack), the main control module can activate the balancing function, adjusting the charging current or using the built-in passive / active balancing circuit to achieve balancing. Safety Protection: Throughout the charging process, the main control unit 4 continuously performs safety checks. If any abnormalities such as overvoltage, overcurrent, or overtemperature are detected, protective measures are immediately implemented, such as reducing charging power, pausing charging, or disconnecting the charging circuit, and the user is alerted via a buzzer, LED light, or display screen.

[0032] Finally, during the charging completion and maintenance phase: When both batteries (or the battery prioritized for charging according to the selected strategy) reach the set full charge conditions (such as current dropping below the threshold, SOC reaching 100%), the main control unit 4 controls the charging unit to stop constant voltage charging and enter trickle charging (optional) or completely stop charging. If a fully charged battery is not removed for a long time, it enters a fully charged float charging state to reduce battery wear.

[0033] Based on the same inventive concept, this application also discloses a portable electronic device including the aforementioned automatic battery switching circuit. This embodiment is currently applied to a portable oxygen concentrator project, and after actual testing and operation, its feasibility is excellent, and customer feedback is positive.

[0034] In the description of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. An automatic battery power switching circuit, characterized in that: The system includes a main control unit (4), a path selection unit (3), a charging management unit (2), a shared power allocation unit, a power input unit, and at least two battery sources. The main control unit (4) is used for overall charging management and decision-making. The path selection unit (3) is electrically connected to the main control unit (4) and the battery sources to control the charging and discharging selection of the battery sources. The charging management unit (2) is communicatively connected to the main control unit (4) and electrically connected to the path selection unit (3) and the battery sources. It includes at least two independently controllable charging units. Each charging unit shares a power topology BOOST-BUCK for narrow voltage DC power path management and multi-unit synchronous boost battery charger control. The shared power allocation unit is connected between the power input unit and the charging management unit (2) to dynamically allocate the input power and current of the charging units in the charging management unit (2). The power input unit is electrically connected to the main control unit (4), the path selection unit (3), and the charging management unit (2) and provides working voltage for each unit.

2. The automatic battery power switching circuit according to claim 1, characterized in that: The main control unit (4) uses a microcontroller, which is a 32-bit GD32F30x series microcontroller.

3. The automatic battery power switching circuit according to claim 1, characterized in that: The charging management unit (2) uses SYV976.

4. The automatic battery power switching circuit according to claim 1, characterized in that: The path selection unit (3) is a dual-battery interface module, using MAX1538.

5. The automatic battery power switching circuit according to claim 4, characterized in that: The MAX1538 is electrically connected to the input / output port of the main control unit (4) via three control lines: charge enable CHRG, battery select BATSEL, and relearn RELRN, and is used to control the charging and discharging selection of the battery source.

6. The automatic battery power switching circuit according to claim 4, characterized in that: The MAX1538 is also connected to the input / output ports of the main control unit (4) through selector status output pins OUT1, OUT2 and OUT3, for outputting the power source, charging status and error flag of the system.

7. The automatic battery power switching circuit according to claim 1, characterized in that: It also includes a display unit (7), which is electrically connected to the main control unit (4) and is used to display the real-time status, charging mode and fault information of the battery.

8. The automatic battery power switching circuit according to claim 1, characterized in that: The shared power distribution unit includes a synchronous step-up power switch (21), which uses a TDM3478.

9. The automatic battery power switching circuit according to claim 7, characterized in that: The battery power source has a built-in BMS battery management module, which is used for current monitoring, internal resistance estimation and / or voltage monitoring, and temperature monitoring.

10. A portable electronic device, characterized in that: It includes an automatic battery power switching circuit as described in any one of claims 1 to 9.

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