Method of charging a rechargeable energy store

Abstract

This invention relates to a method for charging a rechargeable energy storage device (23) of an electronic device (6) via a charging interface (14), wherein a preset charging voltage (V) is applied at the start of the charging process. CI The charging current (I) is applied to the charging interface (14), wherein the charging current (I) flowing through the charging interface (14) is detected during the charging process. CI ), where, based on the measured charging current (I) CI The current state of charge (ODBR, FAST, NORM, TERM) of the energy storage device (23) is determined, wherein, in order to determine the state of charge (ODBR, FAST, NORM, TERM), the charging voltage (V) is determined. CI voltage level (V) CI,FAST V CI,NORM V CI,ODBR V CI,TERM ), and wherein the charging voltage (V) CI Adjust to the specified voltage level (V) CI,FAST V CI,NORM V CI,ODBR V CI,TERM )superior.

Description

Technical Field

[0001] This invention relates to a method for charging a rechargeable energy storage device of an electronic device via a charging interface. The invention also relates to a charging apparatus for implementing the method and a charging system having such an apparatus. Background Technology

[0002] Hearing devices generally refer to electronic devices that assist wearers in improving their hearing. This invention particularly relates to a hearing device designed to fully or partially compensate for the hearing loss of users with hearing impairments. Such hearing devices are also known as “hearing aids” (HA). Additionally, there are hearing devices that protect or improve the hearing of users with normal hearing, such as enhancing speech comprehension in complex auditory environments. Such devices are also known as “personal sound amplification products” (PSAPs). Finally, in the sense of this document, “hearing devices” also include headphones (wired or wireless, with or without active noise cancellation), headsets, etc., worn on or in the ear, as well as implantable hearing devices, such as cochlear implants. Hearing devices can also be part of augmented reality (AR) or virtual reality (VR) systems to output acoustic information of virtual sound sources to the user.

[0003] Typically, hearing devices, especially hearing aids, are designed to be worn on the user's head, and particularly inside or on the user's ear, especially behind-the-ear (BTE) or in-the-ear (ITE) hearing aids. Internally, hearing devices usually have at least one output transducer that converts the output audio signal intended for output into a sound signal perceptible to the user, and then outputs that sound signal to the user.

[0004] In most cases, the output converter is an electroacoustic converter that converts the (electrical) output audio signal into airborne sound, which is then transmitted into the user's ear canal. For hearing devices worn behind the ear, also known as "earphones" ("receivers"), the output converter is typically integrated into the hearing device housing, mostly located on the outside of the ear. In this case, the sound output by the converter is conducted into the user's ear canal through the acoustic tube. Alternatively, the output converter can be placed inside the ear canal, thus outside the housing worn behind the ear. Such hearing devices are also called RIC devices, based on the English name "Receiver In Channel." Hearing devices worn on the ear are very small and do not protrude from the ear canal; therefore, they are also called CIC devices ("Completely in Canal").

[0005] In other configurations, the output transducer can also be designed as an electromechanical transducer, converting the output audio signal into body sound (vibration) and then transmitting the body sound into the user's skull. Additionally, there are implantable hearing devices, particularly cochlear implants, and hearing devices where the output transducer directly stimulates the user's auditory nerve.

[0006] In addition to the output converter, hearing devices typically also have at least one (acoustic-to-electrical) input converter. When the hearing device is in operation, the input converter receives airborne sound from the surrounding environment and converts it into an input audio signal (i.e., an electrical signal that transmits ambient sound information). This signal, also known as the "received sound signal," is periodically output to the user in its raw or processed form, for example, to implement a so-called transparency mode in headphones to actively suppress interference, or, for example, to enhance the user's noise perception in the hearing device.

[0007] In addition, hearing aids typically include a signal processing unit (signal processor). The signal processing unit processes each input audio signal (i.e., modifies its sound information). The signal processing unit then outputs the corresponding processed audio signal (also known as the "output audio signal" or "modified sound signal") to an output converter and / or external device.

[0008] Hearing devices typically use batteries as internal energy storage. Operating time is limited by the battery's capacity (energy charge) and the device's requirements (especially its power consumption). Given the general trend towards miniaturization, smaller batteries are preferred, further limiting their capacity. To avoid frequent battery replacements, hearing devices can use rechargeable batteries (accumulators), such as nickel-metal hydride (NiMH) or lithium-ion (Li-Ion) batteries.

[0009] Hearing devices powered by rechargeable batteries typically have a connection port for establishing an electrical connection with a charger, allowing the rechargeable battery to remain inside the hearing device while charging. During charging, it's necessary to maximize charging efficiency, minimize heat generation, provide more compact portable chargers, and increase the number of charges a portable charger can provide.

[0010] For example, charging efficiency can be improved by providing just enough charging current to charge the device's energy storage while minimizing power consumption.

[0011] In traditional charging methods, a constant charging voltage, such as 5V, is applied to the charging input of the charging regulator in the device being charged. The charging regulator operates in constant current mode, providing a constant charging current to the energy storage device. From the charger's perspective, the charging current is slightly higher than the battery charging current; the extra current is used for the internal operation of the charging regulator during charging. As charging progresses, the battery voltage gradually increases because the constant charging current flows into the battery, and charge accumulates. If the charger's charging voltage is significantly higher than the battery voltage of the energy storage device, especially at the beginning of charging, the total charging power will exceed the total power required to charge the battery and operate the charging regulator. The difference between the total charging power and the power used to charge the battery and operate the charging regulator is excess power, essentially dissipated power, usually as heat from the charging regulator rather than directly used for charging the storage device.

[0012] A method for charging a rechargeable energy storage device in an electronic device is known from US 2024 / 0204570 A1, which achieves higher charging efficiency. To this end, the charging voltage input to the device is continuously adjusted to the battery voltage plus an offset. This maintains the charging power at a level sufficient to charge the energy storage device while minimizing excess power. However, this method requires a communication mechanism between the charging device and the device being charged, such as load modulation or wireless communication, to transmit battery voltage information to the charging device. For example, the charger demodulates the received signal, decodes the battery voltage information, and then adjusts the charging voltage accordingly. This continuous variation of the charging voltage reduces heat dissipation from the charging regulator.

[0013] The downside is that only about 50% of talking and hearing devices on the market lack communication capabilities between the device and the charger, especially in contact charging scenarios. The charger's lack of battery voltage information limits most electronic devices from implementing continuously varying charging voltages, resulting in generally lower charging efficiency. Summary of the Invention

[0014] The technical problem to be solved by this invention is to provide a particularly suitable method for charging a rechargeable energy storage device of an electronic device via a charging interface. The charging method should, in particular, achieve the highest possible charging efficiency without establishing a communication connection with the electronic device. The technical problem to be solved by this invention also includes providing a particularly suitable charger and a particularly suitable charging system.

[0015] In terms of method, the technical problem is solved by a method for charging a rechargeable energy storage device of an electronic device via a charging interface, and in terms of charger and charging system, the technical problem is solved by a charging system of an electronic device having the charging device and a rechargeable energy storage device. Advantageous structural designs and improvements are the technical solutions of the dependent claims. The advantages and designs listed regarding the method also apply to the charger and / or charging system, and vice versa.

[0016] The conjunction “and / or” in this context and below should be understood as meaning that the features connected by this conjunction can appear together or as alternatives to each other.

[0017] In describing the following process steps, the advantageous design of the charger and / or charging system is particularly evident in its ability to perform one or more of the process steps.

[0018] The method according to the present invention is used to charge a rechargeable energy storage device of an electronic device via a charging interface, and is designed and configured for this purpose. The method is primarily implemented by the charger of the electronic device.

[0019] In this context and the following, "charging the energy storage device" specifically refers to charging the energy storage device with electrical energy.

[0020] In this context and the following, "rechargeable energy storage device" specifically refers to a secondary battery in an electronic device that can recover consumed energy through an electrical (charging) process. Here, the energy storage device is designed, for example, as an electrochemical battery, particularly a rechargeable battery, such as a lithium-ion battery.

[0021] The charging interface is specifically designed as a charging contact or charging port (charging pin, charging plug, charging socket) to enable electrical connection with the electronic device during the process. In other words, the electronic device has a complementary (corresponding) charging interface connected to the charging interface for inputting charging energy into the device or energy storage unit. In other words, the charging of the energy storage unit is performed via contact charging or a contact charging scheme. Preferably, the electronic device is equipped with a charging regulator (charging controller) between the corresponding charging interface and the energy storage unit, which monitors the charging process on the device side.

[0022] Electronic devices include, for example, conversation or communication devices, and especially, hearing devices. Hearing devices are defined herein as devices that output audio signals, such as speech or music, such as telephones, smartphones, headphones, earphones, or music players. Hearing devices are preferably hearing aids, i.e., electronic devices that assist the hearing of the wearer (the user or wearer of the hearing aid) during operation. Hearing aids are specifically designed to at least partially compensate for the hearing impairment of users with hearing loss. Other types of hearing devices are designed to assist the hearing of users with normal hearing, i.e., to improve speech perception in complex acoustic environments.

[0023] According to the method, at the start of charging, a stored charging voltage is applied to the charging interface. In other words, a charging voltage with a defined (initial) voltage level is generated, i.e., a constant nominal charging voltage. The magnitude of the charging voltage level is designed to activate the charging regulator of the electronic device.

[0024] Then, during the charging process, the charging current flowing through the charging interface is recorded. For this purpose, the charging interface is continuously monitored, for example, by a current sensor.

[0025] This invention is based on the understanding that the magnitude (amplitude or intensity) of the charging current varies significantly depending on the charging state of the energy storage device on the device side, making the charging current measured at the charging interface useful for determining the current charging state. Because the charging regulator consumes some current, the charging current flowing through the charging interface is slightly higher than the charging current associated with the corresponding charging state.

[0026] According to the present invention, the current charging state of the energy storage device is determined based on the detected or measured charging current during the charging process. According to the present invention, a (rated) voltage level of the charging voltage is also determined based on the determined charging state, and then the charging voltage is set to the determined voltage level. In other words, the charging voltage is changed (adjusted) to a voltage level suitable for the current charging state. Here, "suitable voltage level" refers to a charging voltage higher than the output voltage of the energy storage device in the current charging state, to ensure that the charging process is not interrupted when the device switches between different charging states. This provides a particularly suitable method for charging rechargeable energy storage devices.

[0027] In the method according to the invention, the charging voltage is controlled and / or adjusted based on the charging state of the energy storage device derived from the charging current, thereby reducing power loss and improving charging efficiency. Since the charging state is derived, in particular, from the measured charging current, there is no need for communication with the electronic device or its charging regulator. This simplifies the design of the corresponding charger and reduces the requirements for processing performance.

[0028] In other words, the charging voltage of the charger is adjusted according to the magnitude of the charging current input to the device through the charging interface, without the need for communication between the device and the charger. The method according to the present invention is essentially an improvement upon the method of charging with a continuously variable charging voltage described in document US2024 / 0204570 A1, thereby improving the charging efficiency of electronic devices that do not have communication capabilities with the charger.

[0029] In an advantageous improvement, the current state of charging is determined by comparing the detected charging current with a stored current threshold. In other words, the state of charging of the energy storage device is described at least based on the corresponding charging current value, and the measured charging current is compared with at least one stored charging current value to determine the current state of charging of the device or energy storage device.

[0030] When making threshold comparisons, a certain tolerance range around the charging current value is preferably taken into account. In other words, a charging current range or interval is assigned to the charging state of the energy storage device, wherein, during the threshold comparison process, it is checked whether the recorded charging current is within this range or interval, that is, whether the detected charging current is greater than the lower limit (charging current value minus the tolerance value) and less than the upper limit (charging current value plus the tolerance value).

[0031] Tolerance values ​​can be defined as either a percentage of the charging current or as the absolute value of the charging current.

[0032] Generally, percentage values ​​are preferred for higher charging currents, such as in fast charging scenarios. On the other hand, absolute values ​​are typically used for lower charging currents, such as normal charging, over-discharge recovery, and the end of charging. The reason for using absolute values ​​for lower charging currents is that the percentage tolerance range is narrower compared to higher charging currents. This narrower tolerance range can make it difficult for the charger to accurately determine the current charging state, especially when there are subtle differences in charging current between devices.

[0033] In a preferred design, multiple current thresholds or threshold ranges are stored for different charging states. In other words, multiple discrete charging states are defined for the energy storage device.

[0034] In conceivable applications, for example, four charging states are defined and stored for the energy storage device. These charging states include "over-discharge recovery charging", "fast charging", "normal charging", and "end of charging".

[0035] The following embodiments relate in particular to electronic devices designed as hearing devices or hearing aids. Here, the energy storage device is, for example, a lithium-ion battery, with a fully charged energy storage device or battery voltage of 4.2V to 4.35V. However, these embodiments are also applicable to other electronic devices or voltage ranges.

[0036] When the energy storage voltage falls below its normal operating range, such as below 3.0V, an "over-discharged battery recovery" (ODBR) charging state occurs. ODBR allows the energy storage to recover after being over-discharged. Here, the electronic device may define a lower voltage threshold, such as below 2.5V, possibly due to a protection module between the energy storage and the charge regulator. In this module, for example, when the energy storage voltage falls below its normal operating range, a body diode connected in parallel with a transistor switch turns on to prevent further discharge. The conduction of the body diode causes a voltage drop on the energy storage connection path, allowing the charge regulator to recognize that the energy storage is in an over-discharged state, with its voltage below the normal voltage required for recovery.

[0037] When the energy storage device voltage is within its normal operating range but close to the lower limit, such as between 3.0V and 3.9V, it enters a "fast charging" state. The fast charging state, or the charging process in fast charging mode, is designed to provide the highest possible charging current in the shortest possible charging time. This allows electronic devices to achieve the longest possible usage time within a short charging period. For example, half an hour of fast charging can provide 6 hours of usage time.

[0038] The "normal charging" (NORM) state is characterized by a voltage level above the fast charging threshold. For example, NORM ranges from 3.7V to 4.35V. In NORM charging, the charging process is designed to extend the lifespan of the energy storage device by immediately reducing the charging current once it is fully charged.

[0039] When the energy storage voltage approaches its full charge specification, for example, between 4.2V and 4.35V, it reaches the "terminate charging" state.

[0040] Of the four charging states, the FAST charging state has the highest charging current. This is followed by the NORM charging state, with the ODBR charging state having the second highest current. The TERM charging state has the lowest charging current.

[0041] In a suitable design, the charging voltage is set to a specific voltage level when the state of charging changes. Therefore, when a change in the state of charging is detected—that is, a transition between two defined or stored charging states or between two stored thresholds (ranges)—the charging voltage changes in a step-like or gradual manner. In this step-like change, voltage adjustment occurs only during the transition of charging states, remaining constant for the rest of the time. In contrast, continuous changes in the prior art require continuous monitoring and adjustment of the charging voltage because the energy storage voltage continuously rises during charging. Therefore, the step-like change method places lower computational demands on the charger compared to the continuous change method. This reduced computational load allows for the use of a more economical controller to execute the method. Furthermore, the charger's energy consumption during charging is effectively reduced. Therefore, the method according to the present invention offers particularly lower complexity and higher reliability compared to continuous adjustment of the charging voltage.

[0042] In this design, the charging voltage changes only in response to significant fluctuations in the charging current flow, without requiring the device's energy storage voltage information. Therefore, the charging voltage is only adjusted during charging state transitions, such as from over-discharge (ODBR) to fast charge (FAST), from fast charge (FAST) to normal charge (NORM), and from normal charge (NORM) to end of charge (TERM). These transitions are accompanied by significant changes in the charging current intensity, thus enabling simple, reliable, and safe detection of charging state transitions.

[0043] A stepped charging voltage is a simplified form of a known continuous voltage variation, where the charging voltage is adjusted only when the charging current changes significantly. Changes in the current within the charging regulator of an electronic device trigger the determination of the charging state and adjust the charger's charging voltage.

[0044] The charger according to the invention is designed and configured to charge the rechargeable energy storage of electronic devices. For example, a portable charger has an integrated energy source in the form of a rechargeable energy storage device and / or an energy source interface (power connection, power adapter, etc.) to provide electrical energy, thereby charging the energy storage of the electronic device during the charging process. The energy source can be a battery, such as a power bank, i.e., an electronic device capable of providing charging power (e.g., a laptop or similar device that can also power other electronic devices via a USB interface). The charger can also be a portable (rechargeable) battery module.

[0045] The charger also features a charging interface for energy transfer that can be connected to electronic devices. It further includes a power converter (inverter, transformer) that connects to the charging interface. The power converter connects the charging interface to the charging power source (energy storage device, energy source interface, etc.) and generates a charging voltage during the charging process.

[0046] The charger also features a current sensor to detect the charging current during charging. In particular, it has a voltage and current detection function, namely a voltage and current sensor, to monitor the charging current and voltage at the charging port, as well as the output voltage at the power converter.

[0047] The voltage and current sensing device and the power converter are connected to the controller (i.e., the control unit). This enables a particularly suitable charger. The voltage sensor monitors the charging voltage and feeds the information back to the charger's controller, which is specifically used to regulate the charging voltage and the output voltage of the power converter.

[0048] Here, the controller typically implements the method according to the invention described above using programming and / or circuitry techniques. Specifically, the controller is configured to set a constant rated charging voltage for the power converter at the start of the charging process, then determine the current charging state of the energy storage device on the device side and a suitable voltage level based on the detected charging current intensity during the charging process, and set the charging voltage to that voltage level.

[0049] In a preferred design, the controller comprises, at least in its core, a microcontroller with a processor and a data memory, wherein the functions performed according to the method of the invention are implemented in the form of operating software (firmware) so that the method can be executed automatically when the operating software in the microcontroller is running, and can interact with the device user when necessary. However, within the scope of the invention, the controller may alternatively be composed of non-programmable electronic components, such as application-specific integrated circuits (ASICs) or field-programmable gate arrays (FPGAs), wherein the functions performed according to the method of the invention are implemented by circuit techniques. Furthermore, the controller can also be implemented using window comparator circuit techniques or hardware techniques.

[0050] The measured voltage and current levels are input to the controller to determine and process the changing state of charge. This processing preferably forms a complete feedback loop in which the current state of charge is determined and the output voltage of the power converter is adjusted. In an advantageous embodiment, the output voltage of the power converter is controlled and / or regulated by changing the variable output signal of the controller. In other words, the controller generates an output signal for the power converter to adjust and regulate its output voltage, changing the charging voltage to a level suitable for the current state of charge.

[0051] The output signal can be adjusted or changed using pulse width modulation (PWM) or digital-to-analog conversion (DAC) methods. These changes in the output signal alter the output voltage of the power converter, thereby adjusting the charging voltage at the charging interface and the device input.

[0052] In a preferred design, the charging voltage generated by the power converter is regulated by a regulating loop. This allows the output voltage to vary reliably and safely. Specifically, a closed-loop regulating loop system is designed for the power converter. The power converter may have an external regulating system or, as an IC-based power converter, an integrated regulating system.

[0053] The charging system according to the present invention includes the aforementioned charger and an electronic device having a rechargeable energy storage device. This achieves a particularly suitable charging system. In particular, reliable and efficient charging of the energy storage device can be achieved without establishing an additional communication connection between the charger and the device.

[0054] In a practical design, the electronic device has a charging interface for connecting to a charger, and a charging regulator connected between the charging interface and the energy storage device.

[0055] Electronic devices are preferably hearing instruments or hearing devices, especially hearing aids. Attached Figure Description

[0056] The embodiments of the present invention are further described below with reference to the accompanying drawings. In the drawings:

[0057] Figure 1 A schematic diagram of a charging system with a charger and electronic devices is shown.

[0058] Figure 2 This shows a voltage-current-time diagram of the charging process of the charging system.

[0059] Figure 3 This diagram shows a method flowchart for performing the charging process.

[0060] Figure 4 A schematic diagram of the charger's current sensor is shown.

[0061] Figure 5 A schematic diagram of the charger's voltage sensor is shown.

[0062] Figures 6 to 11 Schematic diagrams showing different embodiments of the charger's power converter are shown.

[0063] Figure 12 A schematic diagram of a regulation circuit for adjusting the output voltage of a power converter is shown.

[0064] Figure 13 , Figure 14 Schematic diagrams of two examples of switch-based power converters with integrated circuits are shown.

[0065] Figure 15 A schematic diagram of a switch-based power converter with integrated circuits is shown.

[0066] Figure 16 A schematic diagram of a window comparator is shown.

[0067] Figure 17 The flowchart illustrates the hardware implementation method for performing the charging process.

[0068] Figure 18 The voltage-current-time diagram of the charging process with a constant charging voltage is shown.

[0069] Figure 19 The voltage-current-time diagram shows the charging process with step-wise voltage adjustment.

[0070] Figure 20 The power-time diagrams are shown for the charging process with a constant charging voltage and the charging process with a stepped adjustment of the charging voltage.

[0071] Figure 21 The efficiency-time diagrams are shown for the charging process using a constant charging voltage and the charging process using a stepped adjustment of the charging voltage.

[0072] In all the accompanying drawings, corresponding parts and dimensions use the same reference numerals. Detailed Implementation

[0073] Figure 1 A charging system 2 with a charger 4 and an electronic device 6 is shown in a simplified schematic diagram. There is no communication connection or communication protocol between the charger 4 and the electronic device 6 in this charging system 2.

[0074] Charger 4 has an energy source 8 for providing charging voltage V. CI The power converter 10, current and voltage sensor (VI sensor) 12, charging interface 14 and controller 16.

[0075] The energy source 8 provides electrical energy for the charging process of the charger 4, and the energy source may be, for example, an energy storage device and / or energy interface integrated in the charger 4, especially a grid port (grid component, current port).

[0076] Power converter 10 converts the input voltage V of energy source 8 into voltage V. IN Converted to output voltage V OUT This output voltage serves as the charging voltage V. CIIt is applied to the charging interface 14. The power converter 10 is, in particular, a converter or transformer.

[0077] The current and voltage sensor 12 is designed as a combined current sensor 18. Figure 4 ) and voltage sensor 20 ( Figure 5 During the charging operation of charger 4, when device 6 is charging, current and voltage sensor 12 monitors the charging current I on charging interface 14. CI and charging voltage V CI and output voltage V OUT Here, voltage sensor 20 is mainly used to monitor the charging voltage V. CI To maintain it at the desired voltage level, current sensor 18 continuously monitors the charging current I. CI .

[0078] The charging interface 14 is specifically designed as a charging contact or charging port (charging contact port), which is electrically connected to the (device) charging interface 21 of the electronic device 6 during charging. The charging interfaces 14 and 21 are designed, for example, as a plug and socket pair for plug-in connection.

[0079] Electronic device 6 has a charging interface 21, a charging regulator 22, and an energy storage device 23 that can be charged by a charger 4. The charging regulator 22 has a charging input terminal 24 connected to the charging interface 21 and a battery terminal 25 connected to the energy storage device 23. The energy storage device 23 is particularly designed as a rechargeable battery, preferably a lithium-ion battery. Electronic device 6 is particularly suitable as a hearing device, preferably a hearing aid, wherein the battery voltage V of the energy storage device 23 is [not specified] during operation of electronic device 6. BAT For example, it is designed to be between 3.0V and 4.2V.

[0080] The controller 16 is technically connected to the current / voltage sensor 12 and the power converter 10. During charging, the current / voltage sensor 12 measures the charging current I. CI Current intensity I sense and the measured charging voltage V CI voltage level V sense The data is sent to controller 16. Controller 16 generates an output signal OS based on the received sensor data, used to control and / or regulate power converter 10 and control and / or regulate output voltage V. OUT .

[0081] Because the charging regulator 24 consumes a certain amount of current, the charging current I flowing through the charging interfaces 14 and 21 is... CI It is slightly higher than the charging current associated with the corresponding state of charge. The following equation illustrates this relationship.

[0082] I CI = IBAT + I OC

[0083] Among them, I BAT I represents the charging current flowing to the energy storage device 23. OC This indicates the current consumption used by the charging regulator 24.

[0084] At the start of the charging process, the controller 16 sets the power converter 10 to a constant nominal charging voltage V. CI Or a constant nominal output voltage V OUT Here, the initial charging voltage V CI The voltage level is designed to enable the charging regulator 24 of electronic device 6 to operate. In other words, the final charging current I... CI The design value is greater than or equal to the current consumption I of the charging regulator 24. OC .

[0085] During the charging process, the charging current I flowing through the charging interface 14 CI The current is detected by current sensor 18 and sent to controller 16. Charging current I CI The intensity depends on the charging state of the energy storage device 23 on the device side, therefore the measured current intensity I sense It can be used to determine the current charging state. Controller 16 is designed to determine the charging state based on the measured current intensity I. sense Determine the current charging state and generate an output signal OS to adjust the charging voltage V. CI Or output voltage V OUT This provides a voltage level suitable for the current charging state.

[0086] For this purpose, for example, based on a current threshold or current threshold range stored in the controller 16 or implemented by circuit technology, four charging states of the energy storage device 23 are stored.

[0087] In this embodiment, for example, four charging states are defined and stored for the energy storage device. These charging states include "Over-Discharge Recovery Charge" (ODBR), "Fast Charge" (FAST), "Normal Charge" (NORM), and "Terminal Charge" (TERM). Among the four charging states, the FAST charging state has the highest charging current I. CI,FAST Secondly, there is the charging current I in the NORM charging state. CI,NORM The ODBR charging state has the second highest charging current I. CI,ODBR The TERM state of charge has the lowest charging current I. CI,TERM The detected charging current I during the charging operation sense The charging current value is compared with the charging state value, and the corresponding charging voltage V is set accordingly. CI,FASTV CI,NORM V CI,ODBR V CI,TERM .

[0088] Preferably, based on the detected current intensity I sense Significant fluctuations, stepwise changes in charging voltage V CI This eliminates the need to transmit charging status information from device 6 to charger 4. Charging voltage V CI Voltage regulation is preferably performed only during charging state transitions, such as from over-discharge (ODBR) to fast charge (FAST), from fast charge (FAST) to normal charge (NORM), and from normal charge (NORM) to end of charge (TERM). These transitions are accompanied by charging current intensities I... sense The obvious changes in the state of charge make it easy, reliable and safe to detect charging state transitions.

[0089] Charging process or step-by-step changing charging voltage V CI In the following Figure 2 and Figure 3 Detailed explanation will follow.

[0090] Figure 2 The charging curve of the charging process is schematically shown in the time-voltage and time-current combined graphs, where the energy storage device 23 charges from an over-discharged state to a nearly fully charged state. Figure 2 In the diagram, the horizontal axis (X-axis) represents time t, and the vertical axis (Y-axis) represents voltage V (left axis) and current I (right axis). Battery voltage V BAT The time variation is represented by the solid line, and the charging current I CI The change over time is represented by a dotted line, and the charging voltage V CI The time change is represented by dashed lines.

[0091] The charging state is ODBR during the time period t0 to t1, FAST during the time period t1 to t2, NORM during the time period t2 to t4, and TERM during the time period t4 to t5.

[0092] When the battery voltage V BAT When the voltage drops below the normal operating range, such as below 3.0V, an ODBR charging state will occur. The ODBR charging state can be recovered after the energy storage device is over-discharged.

[0093] When the battery voltage VBAT is within the normal operating range but close to the lower limit, for example, between 3.0V and 3.9V, it enters the FAST charging state.

[0094] The characteristic of NORM charging state is the battery voltage V. BATAbove the threshold for fast charging. The NORM range is, for example, between 3.7V and 4.35V.

[0095] When the energy storage voltage approaches its full charge specification, for example, between 4.2V and 4.35V, it reaches the TERM charging state, signifying the end of charging. Figure 2 For example, at time t3, the energy storage device 23 is almost fully charged, therefore the charging current I... CI It descends and enters the TERM charging state.

[0096] Figure 3 A flowchart of the charging process is shown. To better explain the process, the recorded current intensity I is... sense The charging current I at a specific time t CI The symbol is I CI,t The controller 16 is specifically designed as a microcontroller (MCU).

[0097] In order to perform the charging process, charging ports 14 and 21 are connected together, and step 26 of the method begins.

[0098] In subsequent method step 27, the charging voltage V CI Set to a constant nominal charging voltage or a constant nominal voltage level. For example, set the charging current I... CI,0 Set to zero (I) CI,0 =0). The voltage level should be selected to activate the charging regulator 22.

[0099] In the method, in step 28, the current-voltage sensor 12 detects the charging current I. CI Current intensity I sense So that the charging current I is applied at the corresponding time t. CI Provided to controller 16 for evaluation.

[0100] In the first threshold comparison 30, the controller 16 will use the currently measured charging current I CI,t Compared with the previously measured charging current I CI,t-1 The comparison is performed at time t-1, taking into account tolerance ranges. In other words, the currently measured charging current I is checked. CI,t Is it greater than the previously measured charging current I? CI,t-1 With tolerance value I tol The difference between them, and the currently measured charging current I CI,t Is it less than the previously measured charging current I? CI,t-1 With tolerance value I tol The sum between them. Therefore, the threshold comparison of 30 is given by the following formula:

[0101] I CI,t-1 – Itol ≤ I CI,t ≤ I CI,t-1 + I tol

[0102] If the comparison result is positive, then the charging current I CI Essentially unchanged, in method step 32, the previous value will be overwritten by the current measurement (I CI,t-1 =I CI,t ).

[0103] If the comparison result is positive, it means that the charging current intensity has changed sufficiently; in other words, the charging current I... CI,t With charging current I CI,t-1 This represents a significant change. This means that the state of charge of the energy storage device 32 has changed significantly. In this case, the current charging current I... CI,t The comparison is made with the thresholds of the stored charge states ODBR, FAST, NORM, and TERM, while taking into account the tolerance range or tolerance value I. tol Therefore, four threshold comparisons (34, 36, 38, and 40) will be performed. These threshold comparisons can be performed in parallel or sequentially, for example, based on the intensity of their respective charging currents (TERM, ODBR, NORM, FAST), or as... Figure 3 As shown, according to the expected time flow of the charging process, the energy storage device 23 charges from an over-discharged charging state to a nearly fully charged charging state.

[0104] In threshold comparison 34, controller 16 will use the currently measured charging current I CI,t With ODBR charging current I CI,ODBR The threshold values ​​are compared, while also considering tolerance ranges. In other words, the currently measured charging current I is checked. CI,t Is it greater than the ODBR charging current I? CI,ODBR Threshold and tolerance value I tol The difference between them, and the currently measured charging current I CI,t Is it less than the ODBR charging current I? CI,ODBR Threshold and tolerance value I tol The sum. Therefore, the threshold comparison 34 is given by the following formula:

[0105] I CI,ODBR – I tol ≤ I CI,t ≤ I CI,ODBR + I tol

[0106] If the comparison result is positive, that is, the currently measured charging current I CI,t Basic and ODBR charging current I CI,ODBRIf the threshold is met, then controller 16 generates output signal OS in method step 42. ODBR (OS = OS ODBR The power converter 10 then sends the charging voltage V to the power converter 10 in method step 44. CI Adjust the charging voltage V to a suitable charging state for "over-discharge recovery charging". CI,ODBR (V CI = V CI,ODBR Then, the charging current is measured in step 28 of the method.

[0107] If the comparison result is negative, that is, the currently measured charging current I CI,t Not in ODBR charging current I CI,ODBR If the tolerance range is within the specified range, then a threshold comparison 36 is performed.

[0108] In threshold comparison 36, controller 16 will use the currently measured charging current I CI,t With FAST charging current I CI,FAST The threshold values ​​are compared, while also considering tolerance ranges. In other words, the currently measured charging current I is checked. CI,t Is it greater than the FAST charging current I? CI,FAST Threshold and tolerance value I tol The difference between them, and the currently measured charging current I CI,t Is it less than the FAST charging current I? CI,FAST Threshold and tolerance value I tol The sum. Therefore, the threshold comparison 36 is given by the following formula:

[0109] I CI,FAST – I tol ≤ I CI,t ≤ I CI,FAST + I tol

[0110] If the comparison result is positive, that is, the currently measured charging current I CI,t Basically in line with FAST charging current I CI,FAST If the threshold is reached, then controller 16 generates output signal OS in method step 46. FAST (OS = OS FAST The power converter 10 then sends the charging voltage V to the power converter 10 in method step 48. CI Adjust the charging voltage V to a suitable "fast charging" state. CI,FAST (V CI = V CI,FAST Then, the charging current is measured in step 28 of the method.

[0111] If the comparison result is negative, that is, the currently measured charging current I CI,t Not in FAST charging current I CI,FAST If the tolerance range is within the specified range, then a threshold comparison of 38 is performed.

[0112] In threshold comparison 38, controller 16 will use the currently measured charging current I CI,t With NORM charging current I CI,NORM The threshold values ​​are compared, while also considering tolerance ranges. In other words, the currently measured charging current I is checked. CI,t Is it greater than the NORM charging current I? CI,NORM Threshold and tolerance value I tol The difference between them, and the currently measured charging current I CI,t Is it less than the NORM charging current I? CI,NORM Threshold and tolerance value I tol The sum. Therefore, the threshold comparison 38 is given by the following formula:

[0113] I CI,NORM – I tol ≤ I CI,t ≤ I CI,NORM + I tol

[0114] If the comparison result is positive, that is, the currently measured charging current I CI,t Basically conforms to NORM charging current I CI,NORM If the threshold is reached, then controller 16 generates output signal OS in method step 50. NORM (OS = OS NORM The power converter 10 then sends the charging voltage V to the power converter 10 in method step 52. CI Adjust the charging voltage V to a suitable level for "normal charging" charging. CI,NORM (V CI = V CI,NORM Then, the charging current is measured in step 28 of the method.

[0115] If the comparison result is negative, that is, the currently measured charging current I CI,t No charging current I in NORM CI,NORM If the tolerance range is within the specified range, then a threshold comparison of 40 is performed.

[0116] In threshold comparison 40, controller 16 will use the currently measured charging current I CI,t With TERM charging current I CI,TERM The threshold values ​​are compared, while also considering tolerance ranges. In other words, the currently measured charging current I is checked. CI,tIs it greater than the TERM charging current I? CI,TERM Threshold and tolerance value I tol The difference between them, and the currently measured charging current I CI,t Is it less than the TERM charging current I? CI,TERM Threshold and tolerance value I tol The sum. Therefore, the threshold comparison 40 is given by the following formula:

[0117] I CI,TERM – I tol ≤ I CI,t ≤ I CI,TERM + I tol

[0118] If the comparison result is positive, that is, the currently measured charging current I CI,t Basically conforms to TERM charging current I CI,TERM If the threshold is reached, then controller 16 generates output signal OS in method step 54. TERM (OS = OS TERM The power converter 10 then sends the charging voltage V to the power converter 10 in method step 56. CI Adjust the charging voltage V to a suitable level for the "charging finished" state. CI,TERM (VCI = V CI,TERM Then, the charging current is measured in step 28 of the method.

[0119] If the comparison result is negative, that is, the currently measured charging current I CI,t Not in TERM charging current I CI,TERM Within the tolerance range, the charging current I CI,t It basically exceeds the tolerance range of the storage charging state ODBR, FAST, NORM, TERM, and initiates method step 28.

[0120] When a change in the state of charging is detected, i.e., a transition between two defined or stored states of charging or between two stored thresholds (ranges), the charging voltage V is adjusted in stages or steps by comparing the tolerance ranges at thresholds of 34, 36, 38, and 40. CI In this step-like variation, voltage adjustment only occurs during the transition between charging states; otherwise, it remains constant. Figure 2 ).

[0121] Figure 4 The design of current sensor 18 is shown, which uses a series resistor R sense This is achieved by connecting it to amplifier circuit 58. The input of amplifier 58 is connected to a series resistor R. senseThe voltage drop across the resistor is derived, and a potential difference is generated when current flows through it. Amplifier 58 then amplifies this voltage drop to a higher level and uses the output signal as a current measurement level I within the voltage range. sense The voltage is sent to the input of the analog-to-digital converter (ADC) of controller 16. Controller 16 uses an algorithm to convert the ADC voltage input into the actual charging current I. CI The numerical representation of the series resistance R. sense The value should be chosen as low as possible to minimize power loss and voltage drop, thereby reducing the output voltage V of the power converter 10. OUT Maintain charging voltage V close to that at charging port 14 CI The level of the series resistor R. sense The value of is preferably less than 1 ohm. An amplifier 58 with the highest possible gain is preferred to compensate for the series resistance R. sense The low resistance improves the resolution of the current level detected by the ADC suitable for controller 16. Typically, amplifier circuit 58 is implemented using a differential operational amplifier with a gain greater than 10.

[0122] For example, Figure 5 The voltage sensor 10 shown is implemented using a voltage divider connected to the amplifier circuit 60. The input of the amplifier 60 is connected to the output of the voltage divider, which is located between two resistors R1 and R2. The voltage divider reduces the voltage at the charging interface 14 to a lower voltage level. The amplifier 60 then follows this input voltage level and uses it as the voltage measurement level V. sense The output is sent to the corresponding ADC port of controller 16. Controller 16 then outputs the measured voltage value V. sense Converted to a numerical value, this value reflects the actual charging voltage V measured at the charging port 14. CI For further processing. The voltage divider divides the charging voltage V from the charging port 14 of the charger 4 into... CI The voltage level is reduced to a level suitable for the ADC input range of controller 16. Preferably, the two resistors R1 and R2 in the voltage divider are selected with high resistance values ​​to minimize the current flowing through the voltage divider circuit during voltage measurement. For example, amplifier circuit 60 can be implemented using a voltage follower that maintains the same voltage level at both the input and output while drawing negligible current from the ADC input of controller 16.

[0123] Measured voltage level and current level I sense V sense The input is fed to the ADC port of controller 16 to determine and process the constantly changing state of charge. This processing preferably forms a complete feedback loop, in which the current state of charge is determined and the output voltage V of power converter 10 is adjusted. OUTThe output voltage V of the power converter 10 is controlled and / or adjusted by changing the output signal OS of the controller 16. OUT In other words, controller 16 generates an output signal OS for power converter 10 to adjust and regulate its output voltage V. OUT And change the charging voltage V CI This ensures that the voltage level matches the appropriate voltage level for the current charging state.

[0124] The output signal OS can be adjusted or changed via pulse width modulation (PWM) or a digital-to-analog converter (DAC). These changes in the output signal OS will alter the output voltage V of the power converter 10. OUT This adjusts the charging voltage V supplied to the charging interface 14 and the input terminal of the device 6. CI .

[0125] exist Figure 1 Importantly, in the hardware implementation shown, the power converter 10 converts the output voltage V OUT To adjust the charging voltage V CI For example, charger 4 has a power source 8 in the form of a USB port, which provides a constant input voltage V of 5V. IN Lithium-ion batteries typically operate within a voltage range of 3.0V to 4.2V. Therefore, power converters 10 that maintain a common ground between input and output can have different topologies.

[0126] Figure 6 This illustration shows a power converter 10 as one implementation of a buck converter. The power converter 10 has a transistor T, an inductor L, a (unloaded) diode D, and an (output) capacitor C, which are connected in a buck converter layout familiar to those skilled in the art. The buck converter is designed to reduce the output voltage V. OUT With input voltage V IN The voltage difference between them.

[0127] Figure 7 The power converter 10 is shown as one implementation of a single-ended primary inductor converter (SEPIC-converter), which can increase or decrease the output voltage V. OUT With input voltage V IN The difference between them. Both buck converters and SEPIC converters have a common ground between their inputs and outputs.

[0128] The power converter 10 here has two inductors L1, L2, a transistor T, two capacitors C1, C2 and a diode D, which are connected according to the SEPIC converter circuit familiar to technicians.

[0129] Figure 8 A power converter 10 in the form of a half-bridge buck converter is shown, which includes two transistors T1 and T2 with body diodes D1 and D2, an inductor L and a capacitor C.

[0130] Figure 9 A power converter 10 designed as a cascaded buck-boost converter is shown, which includes four transistors T1, T2, T3, T4 connected as two bridge arms, each having body diodes D1, D2, D3, D4, an inductor L connected between the bridge arms, and capacitors C1, C2 connected in parallel with the bridge arms respectively.

[0131] Figure 10 A power converter 10, designed as a forward converter, is shown for transformer-based current / voltage conversion. The power converter 10 has three diodes D1, D2, D3, a transistor T, a transformer TR with corresponding winding RW, and a capacitor C.

[0132] Figure 11 A power converter 10, designed as a flyback converter, is shown, which is also used for transformer-based current / voltage conversion. The power converter 10 has a diode D, a transistor T, a transformer TR, and a capacitor C.

[0133] In order to change the output voltage V OUT The system is designed with a closed-loop regulating circuit 62. Figure 12 The illustrated regulating loop system 62 has a feedback loop as a regulating loop 64, which adjusts the output voltage V. OUT Return to reference voltage V ref Compare. Reference voltage V ref This corresponds to the charging voltage V under the current charging state (FAST, NORM, ODBR, TERM). CI,FAST V CI,NORM V CI,ODBR V CI,TERM The voltage is set or selected by the output signal OS of the controller 16.

[0134] Output voltage V OUT With reference voltage V ref The difference between the two values ​​generates an error signal E. This error signal E is input to the PID controller (proportional-integral-derivative) 66, which continuously adjusts the output to correct the output voltage V.OUT With the set reference voltage V ref The PID controller 66 generates a duty cycle by comparing the error signal E with a periodic waveform (e.g., a sawtooth wave). This duty cycle is represented in the form of a pulse width modulation (PWM) signal. The PWM signal is then amplified by a switch driver to control the switching of the power converter 10, turning it on and off. When the PWM signal changes, the inductors and capacitors in the power converter 10 are charged and discharged, thereby changing the output voltage V. OUT Adjust to reference voltage V ref .

[0135] In addition to the power converter 10, the entire closed-loop regulation system 62 can also be implemented in the controller 16. The output voltage V from the control loop 64... OUT The voltage is sent to the ADC of the controller 16 via the voltage sensor 20. The controller 16 generates a PWM signal as the output signal OS to control the switching of the power converter 10, and together with the external switch driver, generates a periodic duty cycle to regulate the power converter 10. Reference voltage V ref It is the voltage level V for each charging state (FAST, NORM, ODBR, TERM). CI,FAST V CI,NORM V CI,ODBR V CI,TERM These voltage levels are stored digitally in the memory of controller 16 or preset, and are adjusted according to the detected charging current I. CI Adjustments will be made.

[0136] Alternatively, a hardware method can be used to implement the closed-loop regulation circuit. Reference voltage V ref This can be provided via a voltage divider or a low-dropout (LDO) circuit. The error signal E is primarily generated by a differential amplifier circuit, which takes the reference voltage V... ref With the output voltage V of power converter 10 OUT A comparison is made. The duty cycle is achieved using a comparator that receives an input of a periodic waveform and the output of a PID amplifier. The PID amplifier has a parallel circuit of a proportional amplifier, an integral amplifier, and a differential amplifier. The PID amplifier processes the error signal E, which is the output of the differential amplifier. The final duty cycle output signal is then sent to a switch driver, which amplifies the signal to a sufficient power level to control the switch in the power converter 10, turning it on and off.

[0137] Closed-loop regulation systems can also be implemented using integrated circuits (ICs) with switch-based power converters, such as... Figure 13 The switch-based buck converter IC shown is... Figure 14 The diagram shows a switch-based SEPIC converter IC. The regulation system is integrated into the feedback control module 68 of the integrated circuit IC, which includes functions such as a comparator, PID controller, PWM generator, switch driver, soft-start reference, current sensor, overcurrent protector, and oscillator. The integrated circuit IC contains a switch or transistor T, which is controlled by the PWM generator and driver within the feedback control module 68.

[0138] The feedback pin 70 of the integrated circuit IC is used to regulate the output voltage V. OUT This is to ensure that it meets the given set value or reference voltage V. ref Output voltage V OUT The output voltage V is adjusted by the ratio of two resistors R1 and R2 connected in series and in parallel with the output terminal of power converter 10. OUT With resistors R1, R2 and reference voltage V ref The relationship between them is described by the following equation, which is derived from the voltage divider:

[0139]

[0140] Integrated circuits (ICs) with circuit-based power converters in Figure 13 The illustrated embodiment also includes a diode D, an inductor L, and a capacitor C, while... Figure 14 In the embodiment shown, there is a diode D, two inductors L1 and L2, and two capacitors C1 and C2.

[0141] In order to adjust the output voltage V of the IC switch-based power converter 10 OUT An additional circuit consisting of voltage source 72 and series resistor R3 is introduced. Figure 15 The output of voltage source 72, connected in series with resistor R3, is linked to the output of a voltage divider and fed into feedback pin 70. The voltage level / voltage rating V of voltage source 72 is adjusted accordingly. source To achieve the output voltage V OUT The change can be achieved by modifying the pulse width modulation (PWM) signal of controller 16 in conjunction with a low-pass filter. Alternatively, the level V of voltage source 72 can be changed by adjusting the output voltage of the digital-to-analog converter (DAC) within controller 16. source . Figure 15 With IC circuit-based buck converter ( Figure 13Taking (e.g.,) as an example, the structure of voltage source 72 and series resistor R3 is explained to obtain a variable output voltage V. OUT By changing the voltage level V source To set the output voltage V of the power converter 10 based on integrated circuit IC. OUT Output voltage V OUT With voltage level V source The relationships between them are represented by equations derived from node analysis:

[0142]

[0143] Apart from Figure 1 and Figure 3 The image shows the method for changing the output voltage V of the IC-based power converter 10. OUT Besides the algorithm, there is an alternative solution, namely using Figure 16 The window comparator circuit shown is as follows. The working principle of the window comparator is that when both the upper comparator 74 and the lower comparator 74 are high, the output voltage V... OUT Increase. When the upper comparator 74 or the lower comparator 74 (or both) is low, V OUT The input voltage range of the window comparator is reduced. The values ​​of resistors R1, R2, and R3 determine the input voltage range of the window comparator, thus producing a high output voltage V. OUT Output voltage, input voltage V IN The resistors R1, R2, R3 and the power supply voltage V of comparator 74 CC The relationship between them is described by the following equation:

[0144]

[0145] Figure 17 This describes the charging voltage V used to achieve the stepped change. CI A hardware method that can achieve similar functionality to a controller algorithm. In the first method step...

[0146] The charging process is initiated in method step 76. First, in method step 78, a constant nominal charging voltage V is applied to the charging interface 14. CI This is to ensure that the charging process starts correctly.

[0147] In subsequent method step 80, the charging current I is measured. CI For example, using Figure 4 The current sensor 18 shown measures the current, converts it to a voltage level, and uses it as the input voltage V in method steps 82, 84, 86, and 88. INThe input is fed into the window comparator. Specifically, four window comparators are provided, one for each stored charge state (ODBR, FAST, NORM, TERM).

[0148] When the voltage level drops to any of the four preset voltage windows (FAST, ODBR, NORM, TERM), the output of the comparator in the corresponding window is increased. In the corresponding method steps 90, 92, 94, and 96, this high-level output activates the voltage source of the IC switch-based power converter 10, or provides a corresponding reference voltage V for the closed system of the hardware method. ref (V CI,FAST V CI,NORM V CI,ODBR V CI,TERM This voltage source typically comes from an LDO circuit or a voltage divider circuit. Finally, in the corresponding method steps 98, 100, 102, and 104, the power converter 10 adjusts its output voltage V connected to the charging interface 14. OUT To achieve a stepped change in charging input voltage V CI .

[0149] For the ODBR charging state, perform method steps 82, 90, and 98 (V). CI =V CI,ODBR For the FAST charging state, perform method steps 84, 92, and 100 (V). CI =V CI,FAST For the NORM charging state, perform method steps 86, 94, and 102 (V). CI =V CI,NORM For the TERM charging state, execute method steps 88, 96, and 104 (V). CI =V CI,TERM ).

[0150] the following Figures 18 to 21 The experiment comparing the full charging of energy storage device 23 is shown, where a conventional constant charging voltage V is used. CI The step-changing charging voltage V in this invention CI A comparison.

[0151] Figure 18 and Figure 19 The charging curves of the charging process are schematically shown in the combined time-voltage and time-current graphs, respectively, during which the energy storage device 23 starts from an over-discharged charging state and charges at a constant charging voltage V. CI ( Figure 18 and the stepped charging voltage V CI ( Figure 19 From an over-discharged charging state to a nearly fully charged charging state. Figure 18 and Figure 19 In the diagram, the horizontal axis (X-axis) represents time t (hours), and the vertical axis (Y-axis) represents voltage V (volts) (left axis) and current I (milliamperes) (mA) (right axis).

[0152] Battery voltage V BAT The time variation is represented by a solid line, while the charging voltage V CI The time variation is represented by a dashed line. The charging current I on charging port 14... CI The time variation is represented by the dashed line, which represents the battery current I input from the charging regulator 22 to the energy storage device 23. BAT The change over time is represented by dotted lines.

[0153] Both charging methods were tested using the same equipment under normal battery operating conditions, with a battery voltage of V. BAT Between 3.0V and 4.2V. Figure 18 It shows a constant charging voltage V CI The complete charging curve of the method, and Figure 19 The charging voltage V shows a stepped variation. CI The complete charging curve of the method. The main difference between the two charging methods lies in the charging voltage V. CI At charging voltage V CI In the step-change method, the charging voltage V CI Adjustments are made based on the mode or charging state (FAST, NORM, TERM), while the charging voltage V CI In the constant-voltage method, a fixed voltage supply is maintained throughout the charging process.

[0154] Figure 20 The time-power graph of the charging process is displayed. Figure 20 In the diagram, the horizontal axis (X-axis) represents time t (hours), and the vertical axis (Y-axis) represents power consumption P milliwatts (mW). Figure 20 It shows a constant charging voltage V CI (P const ) method and stepped charging voltage V CI (P var The power curve P of the method const P var .from Figure 20 As can be clearly seen, when using a stepped voltage variation method, the average power consumption of fast charging (FAST) is reduced by approximately 6mW, while the average power consumption of normal charging (NORM) is reduced by approximately 2mW. This reduction in power consumption indicates that using a stepped voltage variation method... CI The method can produce a more compact portable charger and achieve a higher number of charging cycles.

[0155] Figure 21 The time efficiency graph of the charging process is shown. Figure 21 In the diagram, the horizontal axis (X-axis) represents time t (hours), and the vertical axis (Y-axis) represents efficiency Eff (percentage). Figure 21 The curve Eff, showing the (charging) efficiency of the entire charging process from energy source 8 to battery terminal 25, is displayed. const Eff var And the constant charging voltage (Eff) at the input terminal const The method involves a stepped change in the charging voltage (Eff) at the input terminal. var The methods were compared. Compared to the constant charging voltage method, the stepped voltage method can improve charging efficiency by about 10% in the fast charging state (FAST) and about 5% in the normal charging state (NORM). However, in the terminated charging state (TERM), due to the charging current I flowing to the energy storage device 23... CI The difference is very small, and the charging efficiency of the two methods is similar.

[0156] This invention is not limited to the embodiments described above. Rather, those skilled in the art can derive other variations of the invention from these embodiments within the scope of the disclosed claims without departing from the claimed inventive subject matter. In particular, within the scope of the disclosed claims, all the various features associated with the various embodiments can also be combined in other ways without departing from the claimed inventive subject matter.

[0157] List of reference numerals

[0158] 2 Charging System

[0159] 4 charging devices

[0160] 6 devices

[0161] 8 energy sources

[0162] 10 power converter

[0163] 12 Current and Voltage Sensors

[0164] 14 charging ports

[0165] 16 controllers

[0166] 18 current sensors

[0167] 20 voltage sensors

[0168] 21 charging ports

[0169] 22 Charging Regulator

[0170] 23 energy storage devices

[0171] 24-hour charging input

[0172] 25 battery terminals

[0173] Methods and steps 26, 27, and 28

[0174] 30 threshold comparison

[0175] 32 Methods and Steps

[0176] Threshold comparison of 34, ..., 40

[0177] 42, ..., 56 Methods and steps

[0178] 58 amplifier circuit

[0179] 60 amplifier circuit

[0180] 62 Regulating Loop System

[0181] 64. Regulation loop, feedback loop

[0182] 66 PID controller

[0183] 68 Feedback Control Module

[0184] 70 Feedback Pins

[0185] 72 power supply

[0186] 74 comparator

[0187] 76, ..., 104 Methods and Steps

[0188] V CI Charging voltage

[0189] FAST, ODBR, TERM, NORM charging status

[0190] V CI,FAST V CI,NORM V CI,ODBR V CI,TERM Charging voltage

[0191] V IN Input voltage

[0192] V OUT Output voltage

[0193] I CI Charging current

[0194] I CI,FAST I CI,NORM I CI,ODBR I CI,TERM Charging current

[0195] V BAT Battery voltage

[0196] I BAT Battery current

[0197] I sense Current level

[0198] V sense voltage level

[0199] V voltage

[0200] I Current Intensity

[0201] t time

[0202] R sense Series resistor

[0203] Resistors R1 and R2

[0204] transistors T, T1, and T2

[0205] Inductors L, L1, and L2

[0206] diodes D, D1, D2, and D3

[0207] C, C1, C2 capacitors

[0208] Time intervals t0, t1, t2, t3, t4, and t5

[0209] TR Transformer

[0210] RW turn

[0211] V ref Reference voltage

[0212] Error signal E

[0213] V source voltage level

[0214] P power consumption

[0215] P const P var Power curve

[0216] Eff efficiency

[0217] Eff const Eff var Efficiency curve

Claims

1. A method for charging a rechargeable energy storage device (23) of an electronic device (6) via a charging interface (14), - in, The stored charging voltage (V CI ) is applied to the charging interface (14) at the start of the charging process, - wherein, during the charging process, a charging current (I CI ) flowing through the charging interface (14) is detected, - wherein the current state of charge (ODBR, FAST, NORM, TERM) of the energy store (23) is determined from the measured charging current (I CI ) - wherein, for a determined state of charge (ODBR, FAST, NORM, TERM), a voltage level (V CI ) is determined for the charging voltage (V CI,FAST , V CI,NORM , V CI,ODBR , V CI,TERM ), - and wherein the charging voltage (V CI ) is adjusted to a determined voltage level (V CI,FAST , V CI,NORM , V CI,ODBR , V CI,TERM ).

2. The method according to claim 1, characterized in that, Based on the measured charging current (I) CI ) and the stored current threshold (I CI,FAST I CI,NORM I CI,ODBR I CI,TERM The current charging state (ODBR, FAST, NORM, TERM) is determined by comparing the threshold values ​​of the two states.

3. The method according to claim 1 or 2, characterized in that, Storing multiple current thresholds (I) for different charging states (ODBR, FAST, NORM, TERM) CI,FAST I CI,NORM I CI,ODBR I CI,TERM ), whereby the measured charging current (I) CI ) and the plurality of current thresholds (I CI,FAST I CI,NORM I CI,ODBR I CI,TERM The current charging state (ODBR, FAST, NORM, TERM) is determined by comparing the values ​​of ODBR, FAST, NORM, and TERM.

4. The method according to any one of claims 1 to 3, characterized in that, When the state of charge (ODBR, FAST, NORM, TERM) changes, the charging voltage (V) will be... CI Adjust to the specified voltage level (V) CI,FAST V CI,NORM V CI,ODBR V CI,TERM )superior.

5. A charging device (4) for charging a rechargeable energy storage device (23) of an electronic device (6), the charging device having - A charging interface (14) for transmitting electrical energy that can be coupled to the electronic device (6), - Coupled with the charging interface (14), for generating charging voltage (V) CI The power converter (10) - Used to detect charging current (I CI The current sensor (18), and - A controller (16) for implementing the method according to any one of claims 1 to 4.

6. The charging device (4) according to claim 5, characterized in that, The controller (16) controls and / or regulates the power converter (10) by means of a variable output signal (OS).

7. The charging device (4) according to claim 5 or 6, characterized in that, The charging voltage (V) generated by the power converter (10) is adjusted by the regulating circuit (64). CI ).

8. A charging system (2) having a charging device (4) according to any one of claims 5 to 7 and an electronic device (6) having a rechargeable energy storage device (23).

9. The charging system (2) according to claim 8, characterized in that, The electronic device (6) has a charging interface (21) for coupling with the charging device (6) and a charging regulator (22) coupled between the charging interface (21) and the energy storage device (23).

10. The charging system (2) according to claim 8 or 9, characterized in that, The electronic device (6) is a hearing device, especially a hearing aid.

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