CN103928951A - Charging device and control method thereof - Google Patents

Abstract

The invention discloses a charging device, which is electrically connected with an external power supply and a rechargeable battery pack to execute a charging program and comprises a detection module, a processing module and a charging module, wherein the processing module is electrically connected with the detection module and the charging module; the detection module is used for detecting the electric quantity state of the rechargeable battery pack in a charging procedure and the polarization voltage corresponding to the internal resistance value of the rechargeable battery pack in different electric quantity states; the processing module generates a current adjusting parameter according to the polarization voltage and the electric quantity state; the charging module receives an external power supply, and adjusts the charging current output to the rechargeable battery pack according to the electric quantity state and the current adjustment parameter, so that the waveform of the polarization voltage conforms to the default waveform. The invention also discloses a charging device control method. The invention can improve the recycling times of the rechargeable battery pack, thereby meeting the requirements of users on quick charging of the rechargeable battery pack and better service life.

Description

Charging device and control method thereof

technical field

The invention relates to a charging device and its control method, and in particular to a charging device and its control method which utilizes the change of the internal resistance value in the rechargeable battery pack to control the magnitude of the charging current.

Background technique

Traditional rechargeable battery charging methods mainly include constant trickle current charging method, constant current charging method and constant current-constant voltage two-stage charging method.

Taking the charging device using the 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 default voltage level, the charging device charges the rechargeable battery with a constant voltage equal to the voltage level, and gradually reduces the charging current. When the charging current decreases to a preset threshold current, the charging device will determine that the rechargeable battery has reached a fully charged state and stop charging.

When the rechargeable battery leaves the factory, due to its small internal resistance. Therefore, when using the traditional charging method to charge the rechargeable battery, the rechargeable battery can reach a full state close to 100%. However, as the charging times of the rechargeable battery increase, the electrolyte inside the rechargeable battery will gradually be depleted and the polarization of the positive and negative electrodes will intensify, so that the internal resistance will gradually increase. At this time, if the rechargeable battery is also charged according to the traditional charging method, it will only accelerate the deterioration rate of the positive and negative electrodes and the electrolyte inside the rechargeable battery, thereby shortening the cycle times of the rechargeable battery.

Contents of the invention

The invention provides a charging device. The charging device adjusts the charging current output to the rechargeable battery pack during the next charge by detecting the state of charge of the rechargeable battery pack and the polarization voltage under different states of charge, thereby achieving polarization The purpose of the voltage gradually converging to the default waveform.

The invention provides a charging device. The charging device is electrically connected to an external power source and a rechargeable battery pack to execute a charging process of the rechargeable battery pack. The rechargeable battery pack includes at least one battery unit. The charging device includes a detection module, a processing module and a charging module, wherein the charging module is electrically connected between the external power supply, the rechargeable battery pack and the processing module, and the detection module is electrically connected between the rechargeable battery pack and the processing module. The detection module is used to detect the state of charge of the rechargeable battery pack during the charging process, and the polarization voltage corresponding to the internal resistance of the rechargeable battery pack in different states of charge. The processing module generates a current to adjust parameters according to the polarization voltage and the power state. The charging module receives an external power supply, adjusts the parameters according to the power state and current, and adjusts the charging current output to the rechargeable battery pack, so that the waveform of the polarization voltage conforms to the default waveform.

In other words, a charging device of the present invention 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 detection module, used to detect the power state of the rechargeable battery pack in the charging process and a polarization voltage corresponding to the internal resistance of the rechargeable battery pack under different power states; a processing module, electrically connected to the detection module , generating a current adjustment parameter according to the polarization voltage and the state of power; and a charging module electrically connected to the external power supply, the rechargeable battery pack and the processing module, the charging module receives the external power, and according to the state of power and the processing module The current adjustment parameter adjusts a charging current output to the rechargeable battery pack so that the waveform of the polarization voltage conforms to a preset waveform

The present invention also provides a charging device control method, the control method adjusts the charging current output to the rechargeable battery pack during the next charging by detecting the state of charge of the rechargeable battery pack and the polarization voltage in different states of charge, thereby achieving The purpose of making the polarization voltage gradually converge to the default waveform.

The present invention provides a charging device control method, the control method includes detecting the charge state of the rechargeable battery pack in the charging process and the polarization voltage corresponding to the internal resistance of the rechargeable battery pack under different charge states, wherein the rechargeable battery pack includes at least a battery unit. Then, according to the polarization voltage and the state of charge, a current adjustment parameter is generated. Finally, adjust the parameters according to the power state and current, adjust the charging current output to the rechargeable battery pack, so that the waveform of the polarization voltage conforms to the default waveform.

In summary, the embodiment of the present invention provides a charging device and its control method, which can determine the polarization voltage between the positive electrode and the negative electrode of the rechargeable battery pack under different power states by means of constant current intermittent titration technology. According to the above polarization voltage, the suitable charging current under different power states is determined, so that the waveform of the polarization voltage can conform to the preset waveform.

In order to further understand the characteristics and technical content of the present invention, please refer to the following detailed description and accompanying drawings of the present invention, but these descriptions and accompanying drawings are only used to illustrate the present invention, not to protect the present invention any limitations on the scope.

Description of drawings

Fig. 1 is a functional block diagram of a charging device according to an embodiment of the present invention;

FIG. 2 is a voltage sequence waveform diagram of a rechargeable battery pack when performing a charging procedure for the first time according to an embodiment of the present invention;

3 is a schematic diagram of the polarization voltage, charging current and power state of the rechargeable battery pack when performing the charging procedure for the first time according to an embodiment of the present invention;

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

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

Fig. 5 is a schematic diagram showing the effect comparison between the rechargeable battery pack using the charging device of the present invention to perform the charging process and the traditional charging process;

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

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

[Description of reference signs of main components]

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

Detailed ways

Example of a charging device

Please refer to FIG. 1 , which is a functional block diagram of a charging device 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 execute a charging procedure for the rechargeable battery pack 3 . The charging device 1 includes a detection module 10, a processing module 12 and a charging module 14, wherein the charging module 14 is electrically connected between the external power supply 2, the rechargeable battery pack 3 and the processing module 12, and the detection module 10 is electrically It is connected between the rechargeable battery pack 3 and the processing module 12 .

In general, the external power supply 2 can be, for example, an AC power supply provided by a commercial power supply, or an AC power supply or a DC power supply generated by a generator. Of course, those skilled in the art can also regard the external power supply 2 as output by a host device (such as a desktop computer or a notebook computer) through a universal serial bus (universal serial bus, USB) or IEEE1394 (also known as firewire) interface The direct current power supply, the present invention is not limited here.

The rechargeable battery pack 3 includes at least one battery unit (not shown in FIG. 1 ). In other words, more than two battery units can be connected in series or in parallel to form the rechargeable battery pack 3 . The present invention is not limited to the battery unit. The quantity used and how it is connected. In actual operation, the battery unit may be a lithium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery or a lead storage battery, and the present invention is not limited thereto. Each functional module in the charging device 1 will be described in detail below.

The detection module 10 is used to detect the state of charge (SOC) of the rechargeable battery pack 3 in the charging process and the polarization voltage (polarization voltage) corresponding to the internal resistance of the rechargeable battery pack 3 in each state of charge, which mainly includes There is a power detection unit and a voltage detection unit.

What needs to be mentioned here is 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 charge level 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 power state refers to the power contained in the rechargeable battery pack 3 at present, and is generally expressed as a percentage. A power state of 100% means that the rechargeable battery pack 3 is fully charged, and a power state of 0% means that the rechargeable battery pack is fully charged. Group 3 has been fully discharged. The polarization voltage referred to in the embodiment of the present invention refers to the difference between the charging voltage and the open circuit voltage (OCV) of the rechargeable battery pack 3 when performing the charging program, so the polarization voltage can also be called a rechargeable battery Group 3 voltage drop. In addition, the above-mentioned open circuit voltage refers to the potential difference (also known as potential difference) between the positive pole and the negative pole of the rechargeable battery pack 3 when the rechargeable battery pack 3 is not charging and discharging. The open-circuit voltage of the rechargeable battery pack 3 is different depending on the material used for the electrolyte.

The power detection unit is used to detect the change of the power of the rechargeable battery pack 3 when performing the charging process, so as to obtain the power state of the rechargeable battery pack 3 . In actual operation, the power detection unit can use the open circuit voltage measurement method, the electrolyte specific weight measurement method, the load voltage measurement method, the battery internal resistance measurement method or the coulometer (coulometer, also known as the fuel gauge or charge meter) The measurement method is used for measurement, and the present invention is not limited here, and the above-mentioned measurement methods are conventional measurement methods in the technical field, so details are not repeated here.

The voltage detection unit is used to detect the polarization voltage corresponding to the internal resistance of the rechargeable battery pack 3 under different power states. More specifically, since the internal resistance of the rechargeable battery pack 3 will vary with the level of charge of the rechargeable battery pack 3, the internal resistance will be different under different charge states, causing the polarization voltage to vary with the state of charge of the rechargeable battery pack 3. The internal resistance of the rechargeable battery pack 3 varies. In other words, when the voltage detection unit detects the polarization voltage of the rechargeable battery pack 3 in each state of charge, it can also know the internal resistance value in the state of charge. In actual operation, the voltage detection unit may be an ohmmeter (ohmmeter, also known as a resistance meter), a voltmeter (voltmeter) or a multimeter (multimeter) with an automatic measurement function, and the present invention is not limited here.

The processing module 12 generates a set of current adjustment parameters according to the above-mentioned polarization voltage and the state of charge, and the current adjustment parameters correspondingly indicate the charging current poured into the rechargeable battery pack 3 . In addition, the processing module 12 may also include a memory unit, which may be, for example, random access memory (random access memory, RAM), read-only memory (read-only memory, ROM) or flash memory (flash memory), It is used to store the above-mentioned current adjustment parameters. In actual operation, the processing module 12 may be a microcontroller (microcontroller) or a central processing unit (central processing unit, CPU), which is not limited in the present invention.

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 power state and current adjustment parameters, so that the waveform of the polarization voltage conforms to the default waveform. In other words, the charging module 14 can adjust the desired output power indicated by the current adjustment parameters, thereby outputting charging currents of different magnitudes, thereby achieving the purpose of dynamically adjusting the magnitude of the charging current to charge the rechargeable battery pack 3 with energy. .

In actual operation, the charging module 14 can be a rectifier (converter), a chopper (chopper) or a combination circuit thereof. For example, if the external power supply 2 is an AC power supply, the charging module 14 will include a A set of AC/DC converters (AC/DC converter) used to change the current waveform and a set of DC choppers used to adjust the charging current, those skilled in the art can according to the actual conditions of the external power supply 2 and the rechargeable battery pack 3 , design a circuit that can correspond to the operation of the charging module 14, and the present invention is not limited here.

In order to illustrate more clearly, the actual operation of the charging device 1 of the present invention when performing the charging program of the rechargeable battery pack 3, the rechargeable battery pack 3 all adopts commercial 18650-2.6Ah batteries, and the rechargeable battery pack 3 of this type is a lithium Ion batteries have a capacity of about 2600 milliamps (mAh). It is worth noting that in the embodiment of the present invention, the charge state of the rechargeable battery pack 3 is used as the cutting interval for executing the charging procedure. More specifically, the charge state of the rechargeable battery pack 3 in the embodiment of the present invention is set every % is taken as a segment, but not limited thereto, those skilled in the art can cut out different proportions of the segment according to the actual situation of the rechargeable battery pack 3 . In addition, the open circuit voltages of different types of rechargeable battery packs 3 are different, and the waveform diagrams in the following figures are for example only, and are not intended to limit the waveform shape of the rechargeable battery in the embodiment of the present invention.

It is worth noting that when the rechargeable battery pack 3 executes the charging procedure for the first time, since the charging device 1 does not generate the current adjustment parameters corresponding to the rechargeable battery pack 3, the charging module 14 initially uses a set of preset current The rechargeable battery pack 3 is charged with a constant current. In addition, the magnitude of the charging current is defined according to the capacity of the rechargeable battery pack 3 , and C (capacity) is used as the measurement unit of the charging current. For example, the electric capacity of the rechargeable battery pack 3 (commercial 18650 battery) of the embodiment of the present invention is 2600 mA/h, that is, if the charging current is 2600 mA, the total charging time of the rechargeable battery pack 3 is only one hour It can be charged to saturation, and C is 2600 mA. In the embodiment of the present invention, constant current charging is carried out with a preset current of 0.7C. In other words, the total charging time of the rechargeable battery pack 3 in the embodiment of the present invention when the charging procedure is executed for the first time is about 90 minutes .

Please refer to FIG. 2 . FIG. 2 is a voltage timing waveform diagram of the rechargeable battery pack when the charging process is performed for the first time according to an embodiment of the present invention. As shown in Figure 2, when the rechargeable battery pack 3 performs the charging procedure for the first time, the detection 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 every 2% section When the power state is in the state, it will pause for a default period of time, so that the detection module 10 can accurately detect the polarization voltage in this section. In the embodiment of the present invention, the preset time is 30 minutes, and those skilled in the art can design a reasonable preset time according to the actual situation, and the present invention does not limit it here.

To be more clear, the X-axis of the voltage timing waveform graph shown in Figure 2 represents time (minutes) and the Y-axis represents voltage (Volts), while the peaks in the voltage timing waveform are the charging voltage per 2% state of charge, the voltage The valley value in the timing waveform is the open circuit voltage of every 2% state of charge, and the difference among them is the polarization voltage (also called voltage drop) of this 2% state of charge. In other words, when the rechargeable battery pack 3 executes the charging procedure for the first time, the interval charging method is used to obtain the internal resistance values of the rechargeable battery pack 3 at each 2% charge state. In actual operation, the above-mentioned technique for measuring the internal resistance value in each charge state is called galvanostatic intermittent titration technique (GITT).

Next, collect the polarization voltages of each 2% state of charge in Figure 2 one by one, and express the above data as a schematic diagram based on the state of charge, as shown in Figure 3, which is according to an embodiment of the present invention Schematic diagram of the polarization voltage, charging current and state of charge of the rechargeable battery pack when the charging procedure is performed for the first time. The X-axis shown in Figure 3 represents the capacitance, and each segment on the X-axis represents the state of every 2% of the state of charge, while the bar graph and line graph on the Y-axis represent the extremes of each 2% of the state of charge. voltage and charging current.

It can be clearly observed from FIG. 3 that when the preset current is charged at a constant current of 0.7C, the polarization voltage will change with the state of charge of the rechargeable battery pack 3 . The section with a higher polarization voltage represents that the internal resistance of the rechargeable battery pack 3 in this state of charge is relatively high, so it is more suitable to charge with a smaller charging current when performing a charging procedure in this state of charge, so as to slow down the charging time of the rechargeable battery. Polarization in group 3. Conversely, the section with a lower polarization voltage represents that the internal resistance of the rechargeable battery pack 3 in this state of charge is relatively low, so when performing the charging procedure in this state of charge, a larger charging current can be used to charge, so as to shorten the Charging time at this state of charge. In addition, the adjusted average value of the charging current per 2% state of charge needs to be set equal to the preset current so that the total charging time remains unchanged.

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

The charging current that should be used in every 2% power state = preset current - (polarization voltage in this power state - average polarization voltage) / (linear ratio of charging current to polarization voltage), and the calculated current The adjustment parameters are used in the next execution of the charging program of the rechargeable battery pack 3 . In the embodiment of the present invention, the charging current that should be used in every 2% state of charge = 0.7-(polarization voltage in this state of charge-0.18)/0.24. In other words, since the state of charge of the rechargeable battery pack 3 has been divided into multiple sections, the processing module 12 can generate a set of current adjustment parameters according to the polarization voltage on each section.

Please refer to FIG. 3 and FIG. 4A together. FIG. 4A is a schematic diagram of the polarization voltage, charging current and power state of the rechargeable battery pack after the first calibration according to an embodiment of the present invention. It can be clearly observed from FIG. 4A that the rechargeable battery pack 3 adjusts parameters by means of correcting the current, so that the charging module 14 can adjust the magnitude of the charging current in each state of charge, thereby making the polarization voltage in each state of charge gradually tend to balance .

Next, the processing module 12 generates the next set of current adjustment parameters according to the polarization voltages in each power state after the first correction, as shown in FIG. 4B . Schematic diagram of the polarization voltage, charging current and state of charge after the second correction. It can be seen more clearly from FIG. 4B that after two corrections, the polarization voltages in each charge state are more convergent to the average polarization voltage, so that the waveform of the polarization voltage is fixed within a voltage range. The subsequent corrections are all in the same way as above (this is the trial-and-error method), so no more details will be given.

In addition, it can be clearly observed from FIG. 3 , FIG. 4A and FIG. 4B that if the waveform of the polarization voltage of the rechargeable battery pack 3 is higher than the preset waveform in the state of charge of a certain section, the charging module 14 When the charging program is executed next time in the state of power of this section, the output charging current will be reduced; The module 14 will increase the output charging current the next time the module 14 executes the charging procedure under the power state of this section, so that the waveform of the polarization voltage can gradually converge to the preset waveform.

Please refer to FIG. 5 . FIG. 5 is a schematic diagram showing the effect comparison between the rechargeable battery pack when using the charging device of the present invention to perform the charging process and the traditional charging process. The X-axis shown in FIG. 5 represents the cycle count of the rechargeable battery, which can also be called the charge-discharge cycle, and the Y-axis represents the percentage of the capacity of the rechargeable battery pack 3 .

As shown in Figure 5, the rechargeable battery pack 3 that uses the charging device of the present invention to carry out the charging program increases the service life of 110 times compared with the rechargeable battery pack 9 that uses traditional constant current-constant voltage charging when the electric capacity is 70% left, while When the remaining 60% of the electric capacity has increased the service life of 300 times, in other words, the rechargeable battery pack 3 using the charging device of the present invention to perform the charging procedure can slow down the deterioration speed of the positive and negative electrode materials, thereby avoiding the deterioration of the rechargeable battery pack 3 Performance dips.

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 cycles, so as to extend the cycle times 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. Please refer to FIG. 6A and FIG. 6B. FIG. 6A is a schematic diagram of the 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 polarization diagram of a rechargeable battery pack according to another embodiment of the present invention Schematic diagram of voltage, charging current and state of charge.

As shown in FIG. 6A, if the preset waveform is desired 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 power state and current adjustment parameters, thereby making the The waveforms of the polarization voltages of the rechargeable battery pack 3 in different states of charge reach trapezoidal waveforms. Similarly, as shown in FIG. 6B , if the preset waveform is intended to be a triangular waveform, the charging device 1 of the present invention can make the waveforms of the polarization voltages of the rechargeable battery pack 3 in different states of charge reach triangular waveforms. Therefore, those skilled in the art can directly set the desired waveform of the polarization voltage of the rechargeable battery pack 3 according to the actual usage.

Embodiment of charging device control method

Please refer to FIG. 1 and FIG. 7 together. FIG. 7 is a flow chart of steps of a charging device control method according to another embodiment of the present invention. The charging device 1 in the charging device control method receives an external power source 2 and adjustably outputs charging currents of different magnitudes to the rechargeable battery pack 3 to perform a charging procedure. As shown in Figure 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 internal resistance of the rechargeable battery pack 3 in different states of charge, wherein the charging The battery pack 3 includes at least one battery unit.

Next, in step S72, the charging device 1 generates a set of current adjustment parameters according to the polarization voltage and the state of charge. Finally, in step S74, the charging device 1 will adjust the charging current output to the rechargeable battery pack 3 according to the state of power and the above-mentioned current adjustment parameters, so that the waveform of the polarization voltage conforms to the default waveform, and return to Step S70, and so on.

It should be noted that the state of charge of the rechargeable battery pack 3 is divided into multiple sections, so that the charging device 1 can generate the above-mentioned current adjustment parameters according to the polarization voltage of each section. In more detail, if the waveform of the polarization voltage of the rechargeable battery pack 3 in a state of charge of a certain section is higher than the preset waveform, the charging device 1 will reduce output charging current, if the waveform of the polarization voltage in the state of power of a certain section is lower than the preset waveform, the charging device 1 will increase the output of the charging current when the next time the charging process is performed in this state of power, by This makes the waveform of the polarization voltage in the state of charge of the section gradually converge to the preset waveform.

In addition, when the rechargeable battery pack 3 executes the charging procedure for the first time, the charging device 1 charges the rechargeable battery pack 3 with a constant current at a default current. In addition, the preset waveform is a waveform fixed within a voltage range. In other words, the waveform of the polarization voltage can be a constant voltage waveform. Of course, those skilled in the art can also change the waveform of the polarization voltage to a trapezoidal waveform, a triangular waveform or a horizontal waveform (also known as a stable waveform) according to actual usage conditions, which is not limited by the present invention.

In actual operation, the charging device control method of the present invention can also be applied to electric bicycles or renewable energy (such as solar or wind power) power generation. Specifically, electric bicycles on the market are already equipped with a device that will recharge and flow to the battery when braking. If it is equipped with the charging device control method of the present invention, the charging device will be based on the current state of the battery when braking. Adjusting the size of the recharging current can effectively improve the endurance of the electric bicycle and prolong the service life of the battery. If applied to renewable energy power generation, the renewable energy power generation device can selectively adjust the peak power generation of the renewable energy power generation device according to the internal resistance of the energy storage battery, thereby effectively improving the energy storage efficiency of the renewable energy and prolonging the energy storage. Battery life.

To sum up, the present invention provides a charging device and its control method, which can determine the polarization voltage between the positive and negative electrodes of the rechargeable battery pack under different power states by means of constant current intermittent titration technology, and according to The above polarization voltage determines the suitable charging current under different power states, 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 present invention can increase the cycle times of the rechargeable battery pack, and further meet the user's requirement that the rechargeable battery pack can be charged quickly and have a longer service life.

The above descriptions are only examples of the present invention, and are not intended to limit the protection scope of the present invention.

Claims (12)

1. A charging device, characterized in that it is electrically connected to an external power source and a rechargeable battery pack to perform a charging procedure for the rechargeable battery pack, wherein the rechargeable battery pack includes at least one battery unit, and the charging device includes : A detection module, used to detect the state of charge of the rechargeable battery during the charging process and a polarization voltage corresponding to the internal resistance of the rechargeable battery under different states of charge; a processing module, electrically connected to the detection module, and generating a current adjustment parameter according to the polarization voltage and the state of charge; and A charging module, electrically connected to the external power supply, the rechargeable battery pack and the processing module, the charging module receives the external power supply, adjusts a charging current output to the rechargeable battery pack according to the state of power and the current adjustment parameter, so that The waveform of the polarization voltage conforms to a preset waveform. 2. The charging device according to claim 1, wherein the state of charge of the rechargeable battery pack is divided into a plurality of sections, and the processing module generates the current adjustment parameter according to the polarization voltage of each section . 3 . The charging device according to claim 1 , wherein when the rechargeable battery pack executes the charging procedure for the first time, the charging module charges the rechargeable battery pack with a constant current at a default current. 4 . 4. The charging device as claimed in claim 1, wherein the default waveform is a waveform fixed within a voltage range. 5. The charging device according to claim 1, wherein the default waveform is a trapezoidal waveform, a triangular waveform or a horizontal waveform. 6. The charging device according to claim 1, wherein if the waveform of the polarization voltage of the rechargeable battery pack in a certain state of charge is higher than the preset waveform, the charging module will When the charging program is executed in the state of electricity, the output of the charging current is reduced. If the waveform of the polarization voltage of the rechargeable battery pack in a certain state of electricity is lower than the preset waveform, the charging module will When the charging program is executed in the power state, the charging current is increased and output. 7. A method for controlling a charging device, comprising: Detecting the state of charge of a rechargeable battery pack in a charging process and a polarization voltage corresponding to the internal resistance of the rechargeable battery pack under different states of charge, wherein the rechargeable battery pack includes at least one battery cell; generating a current adjustment parameter according to the polarization voltage and the state of charge; and According to the state of electricity and the current adjustment parameter, a charging current output to the rechargeable battery pack is adjusted so that the waveform of the polarization voltage conforms to a preset waveform. 8. The charging device control method according to claim 7, wherein the state of charge of the rechargeable battery pack is divided into a plurality of sections, and the charging device generates the current according to the polarization voltage of each section Adjustment parameters. 9. The charging device control method according to claim 7, wherein when the charging program is executed for the first time, the charging device charges the rechargeable battery pack with a constant current at a default current. 10. The charging device control method according to claim 7, wherein the default waveform is a waveform fixed within a voltage range. 11. The charging device control method according to claim 7, wherein the default waveform is a trapezoidal waveform, a triangular waveform or a horizontal waveform. 12. The charging device control method according to claim 7, wherein if the waveform of the polarization voltage of the rechargeable battery pack in a certain state of charge is higher than the preset waveform, then at the next time When the charging program is executed in the state of power, the output of the charging current is reduced. If the waveform of the polarization voltage of the rechargeable battery pack in a state of power is lower than the preset waveform, the next time it is in the state of power When the charging program is executed, the charging current is increased.