TW201429023A - Charging device and control method thereof - Google Patents

Abstract

The present invention discloses a charging device electrically connected an external power and a rechargeable battery pack, includes a detecting module, a processing module, and a charging module, wherein the processing module connects the detecting module and the charging module. The detecting module detects the state of charge of the rechargeable battery pack in the charging procedure, and the polarization voltage corresponds to the internal resistance of the rechargeable battery pack from different states of charge. The processing module generates a current adjusting parameter according to the polarization voltage and the state of charge. The charging module receives the external power, and adjusts a charging current which outputs to the rechargeable battery pack according to the state of charge and the current adjusting parameter such that the waveform of the polarization voltage conforms to a predetermined waveform. The charging device efficiently extends the cycle count of the rechargeable battery pack.

Description

Charging device and control method thereof

The present invention relates to a charging device and a control method thereof, and more particularly to a charging device and a control method thereof for controlling a magnitude of a charging current by using a change in an internal resistance value in a rechargeable battery pack.

The conventional charging battery charging method mainly includes a constant trickle current charging method, a constant current charging method, and a constant current-constant voltage two-stage charging method.

Taking a charging device using a constant current-constant voltage two-stage charging method as an example, the charging device initially charges the rechargeable battery with a constant current. When the rechargeable battery reaches a predetermined voltage level, the charging device charges the rechargeable battery with a constant voltage equivalent to the voltage level, and gradually reduces the charging current. When the charging current is reduced to a preset threshold current, the charging device determines that the rechargeable battery has reached a full state and stops charging.

When the rechargeable battery is shipped from the factory, its internal resistance is small. Therefore, when the rechargeable battery is charged using a conventional charging method, the rechargeable battery can reach a state of fullness approaching 100%. However, as the number of times of charging the battery increases, the electrolyte inside the rechargeable battery gradually depletes and the polarization of the positive and negative electrodes increases, so that the internal resistance value gradually increases. At this time, if the rechargeable battery is also charged according to the conventional charging method, only the deterioration speed of the positive, negative electrode and the electrolyte inside the rechargeable battery is accelerated, thereby shortening the number of cycles of charging the battery.

The present invention provides a charging device that transmits detection The state of charge of the rechargeable battery pack and the polarization voltage under different power states are used to adjust the charging current output to the rechargeable battery pack at the next charge, so that the polarization voltage gradually converges toward the preset waveform.

Embodiments of the present invention provide a charging device electrically connected to an external power source and a rechargeable battery pack to perform a charging process of the rechargeable battery pack, wherein the rechargeable battery pack includes at least one battery unit. The charging device includes a detecting module, a processing module and a charging module. The charging module is electrically connected between the external power source, the rechargeable battery pack and the processing module, and the detecting module is electrically connected to the rechargeable battery. Between the group and the processing module. The detection module is configured to detect the state of charge of the rechargeable battery pack in the charging process, and the polarization voltage corresponding to the resistance value of the rechargeable battery pack under different power states. The processing module generates current adjustment parameters according to the polarization voltage and the state of charge. The charging module receives the external power supply, adjusts the charging current output to the rechargeable battery pack according to the state of charge and the current adjustment parameter, so that the waveform of the polarization voltage conforms to the preset waveform.

The present invention provides a charging device control method. The control method adjusts a charging current output to a rechargeable battery pack at a next charging by detecting a state of charge of the rechargeable battery pack and a polarization voltage in a different state of charge. The polarization voltage gradually converges toward the preset waveform.

Embodiments of the present invention provide a charging device control method, which includes detecting a state of charge of a rechargeable battery pack in a charging process and a polarization voltage corresponding to a resistance value of the rechargeable battery pack in a different state of charge, wherein the rechargeable battery pack At least one battery unit is included. Then, based on the polarization voltage and the state of charge, a current adjustment parameter is generated. Finally, according to the state of charge and current adjustment parameters, adjust the charge to the rechargeable battery pack The electric current is such that the waveform of the polarization voltage conforms to the preset waveform.

In summary, the embodiments of the present invention provide a charging device and a control method thereof, and determine a polarization voltage between a positive electrode and a negative electrode of a rechargeable battery pack under different power states through a constant current intermittent titration technique. According to the polarization voltage described above, the charging current suitable for different power states is determined, so that the waveform of the polarization voltage can conform to the preset waveform.

The detailed description of the present invention and the accompanying drawings are to be understood by the claims The scope is subject to any restrictions.

[Embodiment of charging device]

Please refer to FIG. 1. FIG. 1 is a functional block diagram of a charging apparatus according to an embodiment of the present invention. As shown in FIG. 1, the charging device 1 is electrically connected between the external power source 2 and the rechargeable battery pack 3 to perform a charging procedure of the rechargeable battery pack 3. The charging device 1 includes a detecting module 10, a processing module 12, and a charging module 14. The charging module 14 is electrically connected between the external power source 2, the rechargeable battery pack 3 and the processing module 12, and The detecting module 10 is electrically connected between the rechargeable battery pack 3 and the processing module 12.

In general, the external power source 2 can be, for example, an AC power source provided by a commercial power source, or an AC power source or a DC power source generated by a generator. Of course, those having ordinary knowledge in the art can regard the external power source 2 as a host device (for example, a desktop type). The present invention is not limited herein by a DC power supply output from a universal serial bus (USB) or an IEEE 1394 (also known as FireWire) interface.

The rechargeable battery pack 3 includes at least one battery unit (not shown in FIG. 1 ). In other words, two or more battery units can form the rechargeable battery pack 3 via serial connection or parallel connection, and the present invention does not limit the battery here. The number of units used and how they are connected. In practice, the battery unit may be a lithium ion battery, a nickel hydrogen battery, a nickel cadmium battery, or a lead storage battery. The invention is not limited herein. The function modules in the charging device 1 will be described in detail below.

The detecting module 10 is configured to detect a state of charge (SOC) of the rechargeable battery pack 3 in the charging process and a polarization voltage corresponding to the resistance value of the rechargeable battery pack 3 in each state of charge. The utility model mainly comprises a power detecting unit and a voltage detecting unit.

It should be noted that the state of charge of the rechargeable battery pack 3 referred to in the embodiment of the present invention may also be referred to as the degree of charge of the rechargeable battery pack 3, or may be referred to as the remaining power of the rechargeable battery pack 3. In more detail, the state of charge refers to the amount of electricity contained in the currently charged battery pack 3, which is generally expressed as a percentage. When the state of charge is 100%, the charged battery pack 3 is fully charged, and the state of charge is 0%. The rechargeable battery pack 3 has been completely discharged. The polarization voltage referred to in the embodiment of the present invention refers to a difference between a charging voltage and an open circuit voltage (OCV) when the rechargeable battery pack 3 performs a charging procedure, and thus the polarization voltage may also be referred to as a rechargeable battery. Group 3 voltage drop. In addition, the above-mentioned open circuit voltage refers to the positive and negative electrodes of the rechargeable battery pack 3 in a state in which the rechargeable battery pack 3 is not charged and discharged. The potential difference between them (also called the potential difference), therefore, the different types of rechargeable battery packs 3 have different open circuit voltages for the rechargeable battery pack 3 due to the different materials used for the positive electrode, the negative electrode, and the electrolyte.

The power detecting unit is configured to detect a change in the amount of power of the rechargeable battery pack 3 when performing the charging process to obtain a state of charge of the rechargeable battery pack 3. In practice, the power detection unit can use an open circuit voltage measurement method, an electrolyte ratio weight measurement method, a load voltage measurement method, a battery internal resistance measurement method, or a coulometer (also called a fuel gauge or a charge meter). The measurement method is used for measurement, and the present invention is not limited thereto, and the above plurality of measurement methods are already in the measurement method conventionally used in the art, and therefore will not be separately described.

The voltage detecting unit is configured to detect a polarization voltage corresponding to the resistance value of the rechargeable battery pack 3 in different power states. In more detail, since the internal resistance of the rechargeable battery pack 3 varies with the state of charge of the rechargeable battery pack 3, the internal resistance values of the different battery states will be different, resulting in a polarization voltage. The internal resistance of the rechargeable battery pack 3 changes. In other words, when the voltage detecting unit detects the polarization voltage of the rechargeable battery pack 3 in each state of charge, the internal resistance value of the battery state can also be known. In practice, the voltage detecting unit can be an ohmmeter (also called an ohmmeter), a voltmeter or a multimeter with an automatic measuring function, and the invention is not limited herein.

The processing module 12 generates a set of current adjustment parameters according to the polarization voltage and the state of charge described above, and the current adjustment parameter correspondingly indicates the charging current injected into the rechargeable battery pack 3. In addition, the processing module 12 may further include a memory unit, which may be, for example, a random access memory (RAM), a read-only memory (ROM), or a flash memory. Body (flash Memory) for storing the current adjustment parameters described above. In practice, the processing module 12 can be a microcontroller or a central processing unit (CPU), and the invention is not limited herein.

The charging module 14 receives the power provided by the external power source 2, and adjusts the charging current output to the rechargeable battery pack 3 according to the above-mentioned state of charge and current adjustment parameters, so that the waveform of the polarization voltage conforms to the preset waveform. In other words, the charging module 14 can output different amounts of charging current according to the current to be outputted according to the current adjustment parameter, thereby dynamically adjusting the current of the charging current to charge the rechargeable battery pack 3. purpose.

In practice, the charging module 14 can be a rectifier, a chopper, or a combination thereof. For example, if the external power source 2 is an AC power source, the charging module 14 includes one. A group of AC/DC converters for changing the current waveform and a set of DC choppers for adjusting the magnitude of the charging current are generally available to those skilled in the art based on the external power source 2 and the rechargeable battery pack. The actual situation of 3 is designed to correspond to the operation of the charging module 14, and the invention is not limited herein.

To more clearly illustrate the actual operation of the charging device 1 of the present invention when performing the charging process of the rechargeable battery pack 3, the rechargeable battery pack 3 is a commercial 18650-2.6Ah battery, and the rechargeable battery pack 3 of this model is a lithium ion. The battery has a capacitance of approximately 2600 milliamperes (mAh). It should be noted that in the embodiment of the present invention, the state of charge of the rechargeable battery pack 3 is used as a cutting interval for performing a charging procedure, and more specifically, the present invention The state of charge of the rechargeable battery pack 3 in the embodiment is a section every 2%, but not limited thereto, and those having ordinary knowledge in the art can cut different proportions according to the actual situation of the rechargeable battery pack 3. Interval. In addition, the open circuit voltages of the rechargeable battery packs 3 of different models are different. The waveform diagrams of the following figures are for example only, and are not intended to limit the waveform shape of the rechargeable battery of the embodiment of the present invention.

It should be noted that, when the rechargeable battery pack 3 performs the charging process for the first time, since the charging device 1 does not generate the current adjustment parameter corresponding to the rechargeable battery pack 3, the charging module 14 initially starts with a set of presets. The current is charged to the rechargeable battery pack 3 by constant current. Further, the magnitude of the charging current is defined in accordance with the capacitance of the rechargeable battery pack 3, and C (capacity) is used as a unit of measurement of the charging current. For example, the rechargeable battery pack 3 (commercial 18650 battery) of the embodiment of the present invention has a capacity of 2600 mAh/hr, that is, if the charging current is 2600 mA, the total charging time of the rechargeable battery pack 3 takes only one hour. It can be charged to saturation, while C is 2600 mA. In the embodiment of the present invention, the constant current charging is performed with a preset current of 0.7 C. In other words, the total charging time of the rechargeable battery pack 3 in the first execution of the charging procedure in the embodiment of the present invention is about ninety minutes. .

Please refer to FIG. 2. FIG. 2 is a diagram showing voltage timing waveforms of the rechargeable battery pack when the charging program is executed for the first time according to an embodiment of the invention. As shown in FIG. 2, when the charging battery pack 3 performs the charging process for the first time, the detecting module 10 needs to detect the polarization voltage of the rechargeable battery pack 3 under different power states, and the charging module 14 is charged to each. The state of charge of the 2% segment is paused for a predetermined period of time, so that the detection module 10 can accurately detect the polarization voltage in the segment. In the embodiment of the present invention, the preset time is thirty minutes, and those having ordinary knowledge in the technical field may The reasonable preset time is designed according to the actual situation, and the present invention is not limited herein.

More specifically, the X-axis of the voltage timing waveform diagram shown in FIG. 2 represents time (minutes), the Y-axis represents voltage (volts V), and the peak value in the voltage-timed waveform is the charging voltage per 2% state of charge, voltage The valley value in the timing waveform is the open circuit voltage for every 2% state of charge, and the difference is the polarization voltage (also called voltage drop) for this 2% state of charge. In other words, when the rechargeable battery pack 3 performs the charging process for the first time, the interval charging method is adopted to obtain the internal resistance value of the rechargeable battery pack 3 in each of the 2% state of charge. In practice, the above technique for measuring the internal resistance value in each state of charge is called a galvanostatic intermittent titration technique (GITT).

Next, the polarization voltages of each 2% state of charge in FIG. 2 are collected one by one, and the above data is shown as a reference based on the state of charge, as shown in FIG. 3, and FIG. 3 is a diagram of the present invention. A schematic diagram of the polarization voltage, the charging current, and the state of charge of the rechargeable battery pack of the embodiment when the charging process is performed for the first time. The X-axis shown in Figure 3 represents the capacitance, and each segment on the X-axis represents every 2% state of charge, while the bar graph and the line graph on the Y-axis represent the poles for every 2% state of charge. Voltage and charging current.

As can be clearly seen from Fig. 3, when the preset current is charged at a constant current of 0.7 C, the polarization voltage changes depending on the state of charge of the rechargeable battery pack 3. The section with a higher polarization voltage represents a higher internal resistance value of the rechargeable battery pack 3 in this state of charge, so that it is more suitable to charge with a smaller charging current when performing the charging procedure in this state of charge, thereby slowing down the rechargeable battery. The polarization situation within group 3. Conversely, the polarization voltage is higher. The low section represents the lower internal resistance of the rechargeable battery pack 3 in this state of charge, so that the charging process can be performed with a larger charging current during the charging state to shorten the charging in this state of charge. time. In addition, the average value of the adjusted charging current per 2% state of charge must be set equal to the preset current so that the total charging time remains unchanged.

In addition, the charging current and the polarization voltage exhibit a linear proportional relationship. In the embodiment of the present invention, each time the charging speed of 1 C is increased (or lowered), the polarization voltage will increase (or decrease) by 0.24 V, thereby causing processing. Module 12 can generate a set of current adjustment parameters for every 2% state of charge:

The charging current used for every 2% state of charge = preset current - (polarization voltage - average polarization voltage in this state of charge) / (linear ratio of charging current to polarization voltage), and the calculated current The adjustment parameters are applied to the charging process of the next execution of the rechargeable battery pack 3. In the embodiment of the present invention, the charging current used for every 2% state of charge is 0.7-(the polarization voltage in this state of charge is -0.18) / 0.24. In other words, since the state of charge of the rechargeable battery pack 3 has been divided into a plurality of segments, the processing module 12 can generate a set of current adjustment parameters based on the polarization voltage on each segment.

Referring to FIG. 3 and FIG. 4A together, FIG. 4A is a schematic diagram showing polarization voltage, charging current and state of charge of the rechargeable battery pack after the first calibration according to an embodiment of the invention. It can be clearly seen from FIG. 4A that the rechargeable battery pack 3 is corrected by the current adjustment parameter, so that the charging module 14 can adjust the magnitude of the charging current in each state of charge, so that the polarization voltage in each state of charge is gradually increased. Tend to balance.

Then, the processing module 12 generates the next set of current adjustment parameters according to the polarization voltage in each state of charge after the first correction, as shown in FIG. 4B. 4B is a schematic diagram showing polarization voltage, charging current and state of charge of the rechargeable battery pack after the second correction according to an embodiment of the invention. It can be more clearly observed from Fig. 4B that after two corrections, the polarization voltage in each state of charge is more converged toward the average polarization voltage, so that the waveform of the polarization voltage is a waveform fixed within a voltage range. Since the corrections are the same as above (the trial-and-error method), they will not be described again.

In addition, as can be clearly seen from FIG. 3, FIG. 4A and FIG. 4B, if the waveform of the polarization voltage of the rechargeable battery pack 3 in the state of charge of a certain section is higher than the preset waveform, the charging module 14 will reduce the output charging current when the charging process is executed in the power state of this section for the next time; if the waveform of the polarization voltage of the rechargeable battery pack 3 in the power state of a certain section is lower than the preset waveform, When the charging module 14 performs the charging process in the next state of the power state of the segment, the output charging current is increased, so that the waveform of the polarization voltage can gradually converge toward the preset waveform.

Please refer to FIG. 5. FIG. 5 is a schematic diagram showing the performance of the charging battery and the conventional charging program according to the charging device of the present invention. The X-axis shown in FIG. 5 represents the cycle count of the rechargeable battery, which may also be referred to as the number of charge and discharge cycles, and the Y-axis represents the percentage of charge of the rechargeable battery pack 3.

As shown in FIG. 5, the rechargeable battery pack 3 that performs the charging process using the charging device of the present invention has an energy life of 70% remaining, and the life of the rechargeable battery pack 9 using the conventional constant current-constant voltage charging is increased by 110 times. The battery life is increased by 300 times when the remaining capacity is 60%. In other words, the rechargeable battery pack 3 that performs the charging process using the charging device of the present invention The deterioration speed of the positive electrode and the negative electrode material can be slowed down, thereby preventing the performance of the rechargeable battery pack 3 from deteriorating.

In addition, the charging device 1 of the present invention can also generate corresponding current adjustment parameters according to the temperature of the rechargeable battery pack 3 and the number of times of recycling, thereby achieving the purpose of prolonging the number of times of use of the rechargeable battery pack 3.

It should be noted that although the preset waveform in the embodiment of the present invention is a constant voltage waveform, the present invention does not limit whether the preset waveform needs to be a constant voltage waveform. 6A and FIG. 6B, FIG. 6A is a schematic diagram showing polarization voltage, charging current and state of charge of a rechargeable battery pack according to another embodiment of the present invention; FIG. 6B is a diagram showing another embodiment of the present invention; Schematic diagram of the polarization voltage, charging current and state of charge of the rechargeable battery pack.

As shown in FIG. 6A, if the preset waveform is to be a trapezoidal waveform, the charging device 1 can adjust the charging current output to the rechargeable battery pack 3 under different power states according to the state of charge and the current adjustment parameter, so as to enable charging. The waveform of the polarization voltage of the battery pack 3 in different state of charge reaches a trapezoidal waveform. Similarly, as shown in FIG. 6B, if the preset waveform is to be a triangular waveform, the waveform of the polarization voltage of the rechargeable battery pack 3 in different state of charge can be triangulated by the charging device 1 of the present invention. Therefore, those having ordinary knowledge in the art can set the waveform of the polarization voltage of the required rechargeable battery pack 3 according to the actual use situation.

[Embodiment of Control Method of Charging Device]

Please refer to FIG. 1 and FIG. 7. FIG. 7 is a flow chart showing the steps of the charging apparatus control method according to another embodiment of the present invention. This charge The charging device 1 in the electric device control method transmits and adjusts the charging current of different magnitudes to the rechargeable battery pack 3 to perform the charging process by receiving the external power source 2. As shown in FIG. 7, in step S70, the charging device 1 detects the state of charge of the rechargeable battery pack 3 in the charging process and the polarization voltage corresponding to the resistance value of the rechargeable battery pack 3 in different state of charge, wherein The rechargeable battery pack 3 includes at least one battery unit.

Next, in step S72, the charging device 1 generates a set of current adjustment parameters based on the polarization voltage and the state of charge. Finally, in step S74, the charging device 1 adjusts the charging current output to the rechargeable battery pack 3 according to the state of charge and the current adjustment parameter, so that the waveform of the polarization voltage conforms to the preset waveform, and the charging process is executed next time. Go back to step S70, and so on.

It is to be noted that the state of charge of the rechargeable battery pack 3 is divided into a plurality of segments, so that the charging device 1 can generate the above-described current adjustment parameters according to the polarization voltage of each segment. In more detail, if the waveform of the polarization voltage of the rechargeable battery pack 3 in the state of charge of a certain section is higher than the preset waveform, the charging device 1 is reduced when the charging procedure is executed in the next state of the power state. The charging current is output. If the waveform of the polarization voltage in the power state of a certain section is lower than the preset waveform, the charging device 1 increases the output of the charging current when the charging procedure is executed in the next state of the power state. The waveform of the polarization voltage in this section state is gradually converge toward the preset waveform.

Further, when the rechargeable battery pack 3 performs the charging process for the first time, the charging device 1 performs constant current charging of the rechargeable battery pack 3 with a preset current. In addition, the preset waveform is a waveform fixed in a voltage range. In other words, the waveform of the polarization voltage can be a constant voltage waveform. . Of course, those having ordinary knowledge in the field can change the waveform of the polarization voltage into a trapezoidal waveform, a triangular waveform, or a horizontal waveform (also referred to as a stable waveform) according to actual use conditions, and the present invention is not limited thereto.

In practice, the charging device control method of the present invention is more applicable to an electric bicycle or a renewable energy source such as solar energy or wind power. In detail, the electric bicycle on the market has been provided with a device that returns to the battery when the vehicle is braked. If the charging device control method of the present invention is used, the charging device will be based on the current battery condition when the vehicle is braked. Adjust the size of the charging current to effectively improve the battery life and extend the life of the battery. When applied to renewable energy generation, the renewable energy power generation device can selectively adjust the power generation peak of the renewable energy power generation device according to the internal resistance value of the energy storage battery, thereby effectively improving the energy storage efficiency of the renewable energy source and prolonging the energy storage. The life on the battery.

[Possible effects of the examples]

In summary, the embodiments of the present invention provide a charging device and a control method thereof, and determine a polarization voltage between a positive electrode and a negative electrode of a rechargeable battery pack under different power states through a constant current intermittent titration technique. According to the polarization voltage described above, the charging current suitable for different power states is determined, so that the waveform of the polarization voltage can conform to the preset waveform. Thereby, the charging device and the control method thereof of the invention can improve the number of times of recycling of the rechargeable battery pack, thereby achieving the requirement that the user can quickly charge the rechargeable battery pack and have a longer service life.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of the invention.

1‧‧‧Charging device

10‧‧‧Detection module

12‧‧‧Processing module

14‧‧‧Charging module

2‧‧‧External power supply

3, 9‧‧‧Rechargeable battery pack

S70~S74‧‧‧Step process

1 is a functional block diagram of a charging device in accordance with an embodiment of the present invention.

2 is a waveform diagram showing voltage timings of a rechargeable battery pack when a charging program is first executed according to an embodiment of the invention.

FIG. 3 is a schematic diagram showing polarization voltage, charging current, and state of charge of the rechargeable battery pack when the charging process is performed for the first time according to an embodiment of the invention.

4A is a schematic diagram showing polarization voltage, charging current, and state of charge of a rechargeable battery pack after first calibration according to an embodiment of the invention.

4B is a schematic diagram showing polarization voltage, charging current, and state of charge of the rechargeable battery pack after the second correction according to an embodiment of the invention.

FIG. 5 is a schematic diagram showing the performance of a charging battery and a conventional charging program according to the charging device of the present invention.

6A is a schematic diagram showing polarization voltage, charging current, and state of charge of a rechargeable battery pack according to another embodiment of the present invention.

6B is a schematic diagram showing polarization voltage, charging current, and state of charge of a rechargeable battery pack according to still another embodiment of the present invention.

FIG. 7 is a flow chart showing the steps of a charging device control method according to another embodiment of the present invention.

1‧‧‧Charging device

10‧‧‧Detection module

12‧‧‧Processing module

14‧‧‧Charging module

2‧‧‧External power supply

3‧‧‧Rechargeable battery pack

Claims (12)

A charging device is electrically connected to an external power source and a rechargeable battery pack to perform a charging process of the rechargeable battery pack, wherein the rechargeable battery pack includes at least one battery unit, and the charging device includes: a detecting module, a method for detecting a state of charge of the rechargeable battery pack in the charging process and a polarization voltage corresponding to a resistance value of the rechargeable battery pack in a different state of charge; a processing module electrically connected to the detecting module, Generating a current adjustment parameter according to the polarization voltage and the state of charge; and a charging module electrically connecting the external power source, the rechargeable battery pack and the processing module, and the charging module receives the external power source according to the state of charge And the current adjustment parameter, adjusting a charging current output to the rechargeable battery pack such that the waveform of the polarization voltage conforms to a preset waveform. The charging device of claim 1, wherein the state of charge of the rechargeable battery pack is divided into a plurality of segments, and the processing module generates the current adjustment parameter according to the polarization voltage of each segment. The charging device of claim 1, wherein the charging module performs constant current charging on the rechargeable battery pack with a preset current when the charging module is executed for the first time. The charging device of claim 1, wherein the predetermined waveform is a waveform fixed within a voltage range. The charging device of claim 1, wherein the preset waveform is a trapezoidal waveform, a triangular waveform, or a horizontal waveform. The charging device of claim 1, wherein the waveform of the polarization voltage of the rechargeable battery pack in the state of charge is higher than the The preset waveform, the charging module reduces the output of the charging current when the charging program is executed in the power state for the next time, and if the waveform of the polarization voltage of the rechargeable battery pack in a certain state of charge is lower than The preset waveform, the charging module increases the output of the charging current when the charging program is executed in the next state of the power state. A charging device control method includes: detecting a state of charge of a rechargeable battery pack in a charging process and a polarization voltage corresponding to a resistance value of the rechargeable battery pack in a different state of charge, wherein the rechargeable battery pack includes at least one a battery unit; generating a current adjustment parameter according to the polarization voltage and the state of charge; and adjusting a charging current output to the rechargeable battery pack according to the state of charge and the current adjustment parameter, so that the waveform of the polarization voltage conforms to a pre-charge Set the waveform. The charging device control method of claim 7, wherein the state of charge of the rechargeable battery pack is divided into a plurality of segments, and the charging device generates the current adjustment parameter according to the polarization voltage of each of the segments. The charging device control method of claim 7, wherein the charging device performs constant current charging on the rechargeable battery pack with a preset current when the charging program is executed for the first time. The charging device control method of claim 7, wherein the preset waveform is a waveform fixed within a voltage range. The charging device control method according to claim 7, wherein the preset waveform is a trapezoidal waveform, a triangular waveform or a horizontal waveform. For example, the charging device control method of claim 7 of the patent scope, wherein If the waveform of the polarization voltage of the rechargeable battery pack in the state of charge is higher than the preset waveform, the charging current is reduced when the charging procedure is executed in the next state of the power state, and if the power is generated, The waveform of the polarization voltage of the rechargeable battery pack in the state is lower than the preset waveform, and the charging current is increased when the charging procedure is executed in the next state of the power state.