CN204905906U - Control circuit , charging device and charging system charge - Google Patents

Abstract

This utility model provides a charging control circuit, including: a charging unit; multiple power output terminals, each connected to and charging multiple rechargeable batteries; and a control unit electrically connected to the charging unit. The control unit controls the charging unit to charge the batteries according to a first charging mode, which includes: sequentially charging the batteries to a first preset value according to their voltage from high to low; and recharging all batteries to a second preset value. This charging control circuit avoids the situation where a high-voltage battery discharges a large current to a low-voltage battery, effectively protecting the rechargeable batteries. This utility model also provides a charging device and a charging system.

Description

Charging control circuit, charging device and charging system

technical field

The utility model relates to the technical field of battery charging, in particular to a charging control circuit, a charging device and a charging system.

Background technique

At present, most electronic devices such as portable mobile terminals, cameras, and photographic equipment have multiple rechargeable batteries. When the power of the batteries is exhausted, the multiple batteries need to be charged by a charger.

At present, a common charging method in the market is to connect multiple rechargeable batteries in parallel to uniformly charge the rechargeable battery packs connected in parallel. However, this method has many disadvantages. For example, after rechargeable batteries with different voltage values are connected in parallel, the high-voltage battery may discharge the low-voltage battery. Usually, the discharge current will be very large, which is likely to cause danger. In addition, after multiple rechargeable batteries are connected in parallel, the charger may charge the low-voltage battery first during the charging process, because once it is fully charged, several batteries will be fully charged at the same time. If you want to use a fully charged battery during charging, you need to wait longer. For a long time, it is not convenient for users to use.

Utility model content

In view of the above, it is necessary to provide a charging control circuit, a charging device and a charging system.

A charging control circuit, comprising:

charging unit;

There are multiple power output terminals, which are respectively used to connect to multiple rechargeable batteries and charge the multiple rechargeable batteries; and

a control unit electrically connected to the charging unit;

Wherein, the control unit controls the charging unit to charge the multiple batteries according to a first charging mode, and the first charging mode is: according to the order of battery voltages of the multiple rechargeable batteries from high to low The plurality of rechargeable batteries are respectively charged to a first preset value, and then all the rechargeable batteries are recharged simultaneously to a second preset value, and the first preset value is smaller than the second preset value.

Further, the control unit is one of a field programmable gate array, a micro-control chip embedded with a control program, or a single-chip microcomputer.

Further, the charging control circuit also includes:

a switch unit, the switch unit is connected between the charging unit and the plurality of power output terminals; and

a mode switching unit electrically connected to the control unit;

Wherein, the control unit switches to the first charging mode or the second charging mode according to the switching signal sent by the mode switching unit, and outputs a corresponding switching signal to the switching unit, and the second charging mode is: Charge the multiple rechargeable batteries sequentially according to the battery voltage of the multiple rechargeable batteries from high to low; the switch unit disconnects or connects the charging unit and the multiple rechargeable batteries according to the switch The electrical connection between the output terminals of the power supply.

Further, the switch unit is a relay switch;

or

The switch unit is a MOS tube, the source of the MOS tube is electrically connected to the charging unit, the drain of the MOS tube is electrically connected to the corresponding power output terminal, and the gate of the MOS tube is electrically connected to the control unit;

or

The switch unit is an NPN triode, the collector of the NPN triode is electrically connected to the charging unit, the emitter is electrically connected to the corresponding power output terminal, and the base is electrically connected to the control unit.

Further, the mode switching unit includes a button, and the switching signal is output by operating the button;

or

The mode switching unit includes an automatic switching circuit for automatically outputting the switching signal after detecting a preset trigger condition.

Further, the charging control circuit also includes a voltage acquisition unit, which is connected between the charging unit and the switch unit, and connected to the control unit; the voltage acquisition unit is used to acquire the The voltage values of the plurality of rechargeable batteries, the control unit controls the conduction or disconnection of the plurality of power output terminals and the charging unit through the switch unit according to the voltage values collected by the voltage acquisition unit.

Further, the control unit controls the plurality of power output terminals to be connected to the charging unit one by one through the switch unit, so as to control the voltage acquisition unit to collect the battery voltage of each rechargeable battery;

Or/and, in the first charging mode, the control unit further controls the power output terminal corresponding to the rechargeable battery with the largest voltage value among the detected battery voltages to be turned on, while the other power output terminals are powered off, so as to making the charging unit charge the rechargeable battery with the highest battery voltage to the first preset value.

Further, the charging unit sequentially charges the plurality of rechargeable batteries to a first preset value by means of constant current charging;

Or/and, the charging unit charges the plurality of rechargeable batteries from the first preset value to a second preset value by means of constant voltage charging.

A charging device, comprising a casing and a charging control circuit installed in the casing, wherein the charging control circuit includes:

charging unit;

There are multiple power output terminals, which are respectively used to connect to multiple rechargeable batteries and charge the multiple rechargeable batteries; and

a control unit electrically connected to the charging unit;

Wherein, the control unit controls the charging unit to charge the multiple batteries according to a first charging mode, and the first charging mode is: according to the order of battery voltages of the multiple rechargeable batteries from high to low The plurality of rechargeable batteries are respectively charged to a first preset value, and then all the rechargeable batteries are recharged simultaneously to a second preset value, and the first preset value is smaller than the second preset value.

Further, the control unit is one of a field programmable gate array, a micro-control chip embedded with a control program, or a single-chip microcomputer.

Further, the charging control circuit also includes:

a switch unit, the switch unit is connected between the charging unit and the plurality of power output terminals; and

a mode switching unit electrically connected to the control unit;

Wherein, the control unit switches to the first charging mode or the second charging mode according to the switching signal sent by the mode switching unit, and outputs a corresponding switching signal to the switching unit, and the second charging mode is: Charge the multiple rechargeable batteries sequentially according to the battery voltage of the multiple rechargeable batteries from high to low; the switch unit disconnects or connects the charging unit and the multiple rechargeable batteries according to the switch The electrical connection between the output terminals of the power supply.

Further, the switch unit is a relay switch;

or

The switch unit is a MOS tube, the source of the MOS tube is electrically connected to the charging unit, the drain of the MOS tube is electrically connected to the corresponding power output terminal, and the gate of the MOS tube is electrically connected to the control unit;

or

The switch unit is an NPN triode, the collector of the NPN triode is electrically connected to the charging unit, the emitter is electrically connected to the corresponding power output terminal, and the base is electrically connected to the control unit.

Further, the mode switching unit includes a button, and the switching signal is output by operating the button;

or

The mode switching unit includes an automatic switching circuit for automatically outputting the switching signal after detecting a preset trigger condition.

Further, the charging control circuit also includes a voltage acquisition unit, which is connected between the charging unit and the switch unit, and connected to the control unit; the voltage acquisition unit is used to acquire the The voltage values of the plurality of rechargeable batteries, the control unit controls the conduction or disconnection of the plurality of power output terminals and the charging unit through the switch unit according to the voltage values collected by the voltage acquisition unit.

Further, the control unit controls the plurality of power output terminals to be connected to the charging unit one by one through the switch unit, so as to control the voltage acquisition unit to collect the battery voltage of each rechargeable battery;

Or/and, in the first charging mode, the control unit further controls the power output terminal corresponding to the rechargeable battery with the largest voltage value among the detected battery voltages to be turned on, while the other power output terminals are powered off, so as to making the charging unit charge the rechargeable battery with the highest battery voltage to the first preset value.

Further, the charging unit sequentially charges the plurality of rechargeable batteries to a first preset value by means of constant current charging;

Or/and, the charging unit charges the plurality of rechargeable batteries from the first preset value to a second preset value by means of constant voltage charging.

A charging system, comprising a plurality of rechargeable batteries and a charging control circuit for charging the plurality of rechargeable batteries, wherein the charging control circuit includes:

charging unit;

There are multiple power output terminals, which are respectively used to connect to the multiple rechargeable batteries and charge the multiple rechargeable batteries; and

a control unit electrically connected to the charging unit;

Wherein, the control unit controls the charging unit to charge the multiple batteries according to a first charging mode, and the first charging mode is: according to the order of battery voltages of the multiple rechargeable batteries from high to low The plurality of rechargeable batteries are respectively charged to a first preset value, and then all the rechargeable batteries are recharged simultaneously to a second preset value, and the first preset value is smaller than the second preset value.

Further, the control unit is one of a field programmable gate array, a micro-control chip embedded with a control program, or a single-chip microcomputer.

Further, the charging control circuit also includes:

a switch unit, the switch unit is connected between the charging unit and the plurality of power output terminals; and

a mode switching unit electrically connected to the control unit;

Wherein, the control unit switches to the first charging mode or the second charging mode according to the switching signal sent by the mode switching unit, and outputs a corresponding switching signal to the switching unit, and the second charging mode is: Charge the multiple rechargeable batteries sequentially according to the battery voltage of the multiple rechargeable batteries from high to low; the switch unit disconnects or connects the charging unit and the multiple rechargeable batteries according to the switch The electrical connection between the output terminals of the power supply.

Further, the switch unit is a relay switch;

or

The switch unit is a MOS tube, the source of the MOS tube is electrically connected to the charging unit, the drain of the MOS tube is electrically connected to the corresponding power output terminal, and the gate of the MOS tube is electrically connected to the control unit;

or

The switch unit is an NPN triode, the collector of the NPN triode is electrically connected to the charging unit, the emitter is electrically connected to the corresponding power output terminal, and the base is electrically connected to the control unit.

Further, the mode switching unit includes a button, and the switching signal is output by operating the button;

or

The mode switching unit includes an automatic switching circuit for automatically outputting the switching signal after detecting a preset trigger condition.

Further, the charging control circuit also includes a voltage acquisition unit, which is connected between the charging unit and the switch unit, and connected to the control unit; the voltage acquisition unit is used to acquire the The voltage values of the plurality of rechargeable batteries, the control unit controls the conduction or disconnection of the plurality of power output terminals and the charging unit through the switch unit according to the voltage values collected by the voltage acquisition unit.

Further, the control unit controls the plurality of power output terminals to be connected to the charging unit one by one through the switch unit, so as to control the voltage acquisition unit to collect the battery voltage of each rechargeable battery;

Or/and, in the first charging mode, the control unit further controls the power output terminal corresponding to the rechargeable battery with the largest voltage value among the detected battery voltages to be turned on, while the other power output terminals are powered off, so as to making the charging unit charge the rechargeable battery with the highest battery voltage to the first preset value.

Further, the charging unit sequentially charges the plurality of rechargeable batteries to a first preset value by means of constant current charging;

Or/and, the charging unit charges the plurality of rechargeable batteries from the first preset value to a second preset value by means of constant voltage charging.

The above-mentioned charging control circuit, charging device and charging system charge all the rechargeable batteries to the first preset value respectively according to the order of battery voltage from high to low, and then charge all the rechargeable batteries at the same time, that is, perform parallel charging. When multiple rechargeable batteries are charged at the same time, the battery voltage values of the rechargeable batteries remain consistent, that is, the first preset value, so there is no high-voltage battery discharging a low-voltage battery with a large current, which can effectively protect The purpose of recharging the battery is also to shorten the charging time of the whole system.

Description of drawings

FIG. 1 is a functional block diagram of a charging control circuit according to an embodiment of the present invention.

FIG. 2 is another functional block diagram of the charging control circuit of the embodiment of the present invention.

FIG. 3 is a schematic diagram of one application of the charging control circuit of the embodiment of the present invention.

FIG. 4 is a schematic diagram of another application of the charging control circuit of the embodiment of the present invention.

Description of main component symbols

charging control circuit 100 Power output 10 charging unit 20 control unit 30 switch unit 40 Voltage Acquisition Unit 50 mode switching unit 70 Rechargeable Battery 200 removable device 300 powerplant 301 ESC 303 motor 305 propeller 307

The following specific embodiments will further illustrate the utility model in conjunction with the above-mentioned accompanying drawings.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

It should be noted that when an element is referred to as being “electrically connected” to another element, it may be directly on the other component or there may be an intervening element. When an element is considered to be "electrically connected" to another element, it may be connected by contact, eg, by a wire connection, or non-contact, eg, by a non-contact coupling.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of this invention. The terminology used in the description of the utility model herein is only for the purpose of describing specific embodiments, and is not intended to limit the utility model. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Below in conjunction with the accompanying drawings, some embodiments of the present utility model will be described in detail. In the case of no conflict, the following embodiments and features in the embodiments can be combined with each other.

Please refer to FIG. 1 , a preferred embodiment of the present invention provides a charging control circuit 100 for charging a plurality of rechargeable batteries 200 . The charging control circuit 100 includes a plurality of power output terminals 10 , a charging unit 20 , a control unit 30 , a plurality of switching units 40 corresponding to the power output terminals 10 , and a voltage acquisition unit 50 .

The plurality of power output ends 10 are connected in parallel with each other and each power output end 10 is electrically connected to the charging unit 20, and a switch unit is also connected between each power output end 10 and the charging unit 20 40.

The charging unit 20 may include circuit modules such as a power input terminal, an AC-DC conversion circuit or/and a DC conversion circuit, etc., to be electrically connected to an external power source, and the external power source is processed into a corresponding charging voltage, and then output to the The output terminal 10 of the power supply.

The control unit 30 may be a Field-Programmable Gate Array (Field-Programmable Gate Array, FPGA), a Micro-Controller Unit (MCU) or a single-chip microcomputer embedded with a control program. The control unit 30 can be electrically connected to a plurality of the switch units 40 through a control bus, for outputting corresponding switch signals to the switch units 40 . The switch unit 40 receives the switch signal sent by the control unit 30, and turns on or off the electrical connection between the charging unit 20 and the corresponding power output terminal 10 according to the switch signal, so that the charging unit 20 charges the rechargeable battery 200 electrically connected to the power output terminal 10 through the turned-on switch unit 40 and the corresponding power output terminal 10 .

The switch unit 40 may be a metal oxide semiconductor field effect transistor (MetalOxideSemiconductorFieldEffectTransistor, MOS transistor), or other electronic switches such as a relay. In this embodiment, the working mode of the switch unit 40 is described by taking the switch unit 40 as an example of a MOS tube. The source of the MOS tube is connected to the charging unit 20, and the drain of the MOS tube is connected to the corresponding power output terminal. 10, and the gate of the MOS transistor is connected to the control unit 30 through the control bus. The control unit 30 sends a corresponding switch signal, for example, a high-level signal or a low-level signal, to the gate of the MOS transistor, so as to control the conduction or disconnection of the MOS transistor. When the MOS transistor is turned on, the charging unit 20 can charge the rechargeable battery 200 through the turned on MOS transistor and the corresponding power output terminal 10 .

It can be understood that, in other implementation manners, the switch unit 40 may also be an electronic switch such as an NPN transistor. For example, when the switch unit 40 is an NPN transistor, the base of the NPN transistor is connected to the control unit 30 through the control bus, the collector is electrically connected to the charging unit 20, and the emitter is connected to the corresponding The power supply output terminal 10 is electrically connected.

The voltage acquisition unit 50 is electrically connected between the charging unit 20 and the switch unit 40 , and is electrically connected to the control unit 30 . The voltage collecting unit 50 is used to collect the voltage of each rechargeable battery 200 , and transmit the collected voltage of each rechargeable battery 200 to the control unit 30 .

Further, when the plurality of switch units 40 are all disconnected to disconnect the electrical connection between the charging unit 20 and the plurality of power output terminals 10, the voltage collected by the voltage acquisition unit 50 is the The output voltage of the charging unit 20. When one of the switch units 40 in the plurality of switch units 40 is turned on and the other switch units 40 are all turned off, the voltage collected by the voltage acquisition unit 50 is corresponding to the switch unit 40 in the conduction state. The battery voltage of the rechargeable battery 200 connected to the power output terminal 10 of the power supply. In this way, the control unit 30 controls the switch units 40 to be turned on one by one, so as to control the voltage acquisition unit 50 to respectively detect the battery voltages of the multiple rechargeable batteries 200 connected to the power output terminals 10 . The control unit 30 further controls the on and off of the switch unit 40 according to the voltage collected by the voltage collection unit 50, and then turns on or off the connection between the charging unit 20 and the corresponding power output terminal 10. electrical connection.

It can be understood that the charging control circuit 100 also includes a mode switching unit 70 . The mode switching unit 70 is electrically connected to the control unit 30 . The mode switching unit 70 is configured to output a switching signal, such as a high level signal or a low level signal, to control the charging control circuit 100 to switch between the first charging mode and the second charging mode. For example, when the control unit 30 receives the high level signal sent by the mode switching unit 70, the control unit 30 works in the first charging mode. When the control unit 30 receives the low level signal sent by the mode switching unit 70, the control unit 30 switches to the second charging mode.

It can be understood that the switching signal output by the mode switching unit 70 can be realized by means of hardware or software. For example, the mode switching unit 70 includes buttons. In this way, when the button is pressed, the mode switch unit 70 outputs a high level signal to the control unit 30 to control the control unit 30 to switch to the first charging mode. When the button is not pressed, the mode switching unit 70 outputs a low level signal to control the control unit 30 to switch to the second charging mode. Of course, in other implementation manners, the mode switching unit 70 may also include an automatic switching circuit, which is used to automatically output corresponding high-level signals and low-level signals after detecting preset trigger conditions to switch The working mode of the charging control circuit 100 .

It should be noted that the relationship between the high and low level signals output by the mode switching unit 70 and the corresponding charging modes can be adjusted as required. For example, in other embodiments, it can be set that when the mode switching unit 70 outputs a high level signal, the control unit 30 switches to the second charging mode, and when the mode switching unit 70 outputs a low level signal , the control unit 30 switches to the first charging mode. Of course, in other embodiments, the charging control circuit 100 can also be configured such that when the mode switching unit 70 does not output any switching signal to the control unit 30, the charging control circuit 100 maintains the current charging mode, For example, the first charging mode or the second charging mode, and once the control unit 30 receives the switching signal output by the mode switching unit 70, then switch the charging mode, such as switching from the first charging mode to the second charging mode or Switching from the second charging mode to the first charging mode.

Further, when the charging control circuit 100 works in the first charging mode, the control unit 30 controls the switch units 40 to be turned on one by one, that is, controls the plurality of power supply output terminals 10 and the charging unit 20 one by one. is turned on, so that the voltage acquisition unit 50 can detect the battery voltages of the multiple rechargeable batteries 200 connected to the output terminals 10 of the power supply one by one. The control unit 30 further controls the switch unit 40 corresponding to the rechargeable battery 200 with the largest voltage value among the detected battery voltages to be turned on, while the other switch units 40 are turned off, so as to control the detected battery voltage. The power output terminal 10 corresponding to the rechargeable battery 200 with the highest voltage value is turned on, while the other power output terminals 10 are powered off, so that the charging unit 20 charges the rechargeable battery 200 with the highest battery voltage value first. When the rechargeable battery 200 with the highest voltage is charged to the first preset value, the voltage acquisition unit 50 detects the battery voltages of the remaining rechargeable batteries 200 one by one. The control unit 30 further controls the switch unit 40 corresponding to the rechargeable battery 200 with the largest voltage value among the remaining rechargeable batteries 200 to be turned on, while the other switch units 40 are turned off, so that the charging unit 20 can control the remaining rechargeable batteries 200. The rechargeable battery 200 with the highest voltage value is charged to the first preset value. By analogy, the control unit 30 controls the charging unit 20 to sequentially charge the plurality of rechargeable batteries 200 to the first preset value in order of the battery voltages of the rechargeable batteries 200 from high to low. Next, the control unit 30 controls all the switch units 40 to be turned on, so that the charging unit 20 recharges all the rechargeable batteries 200 to a second preset value.

In the above-mentioned first charging mode, the charging control circuit 100 charges all the rechargeable batteries 200 to the first preset value respectively according to the order of battery voltage from high to low, and then charges all the rechargeable batteries 200 at the same time, That is, parallel charging is performed. Since multiple rechargeable batteries 200 are charged at the same time, the battery voltage values of the rechargeable batteries 200 remain consistent, that is, the first preset value, so there is no high-voltage battery discharging a low-voltage battery with a large current, which can play a role The purpose of effectively protecting the rechargeable battery 200 is also to shorten the charging time of the entire system. It can be understood that, in the first charging mode, the charging unit 20 can sequentially charge the plurality of rechargeable batteries 200 to the first preset value by means of constant current charging, and then use constant voltage charging. The plurality of rechargeable batteries 200 are charged sequentially from the first preset value to the second preset value.

When the charging control circuit 100 works in the second charging mode, the control unit 30 controls the switch units 40 to be turned on one by one, that is, controls the plurality of power supply output terminals 10 to be turned on with the charging unit 20 one by one, Therefore, the voltage acquisition unit 50 can detect the battery voltages of multiple rechargeable batteries 200 connected to the power supply output terminal 10 one by one. The control unit 30 further controls the switch unit 40 corresponding to the rechargeable battery 200 with the largest voltage value among the detected battery voltages to be turned on, while the other switch units 40 are turned off, so as to control the detected battery voltage. The power output terminal 10 corresponding to the rechargeable battery 200 with the highest voltage value is turned on, while the other power output terminals 10 are powered off, so that the charging unit 20 first charges the rechargeable battery 200 with the highest voltage value, and directly charges to the second rechargeable battery 200. Two default values. When the rechargeable battery 200 with the highest battery voltage is fully charged, the voltage acquisition unit 50 detects the battery voltages of the remaining rechargeable batteries 200 one by one. The control unit 30 further controls the switch unit 40 corresponding to the rechargeable battery 200 with the largest voltage value among the remaining rechargeable batteries 200 to be turned on, while the other switch units 40 are turned off, so that the charging unit 20 can control the remaining rechargeable batteries 200. The rechargeable battery 200 with the highest battery voltage is charged, and is directly charged to the second preset value. By analogy, the control unit 30 detects the battery voltages of the multiple rechargeable batteries 200, and sequentially charges the multiple rechargeable batteries 200 according to the order of the battery voltages from high to low.

In the above-mentioned second charging mode, the charging control circuit 100 can preferentially charge the rechargeable battery 200 with the highest voltage value, so that a rechargeable battery 200 can be fully charged in the shortest time to meet the needs of users.

In this embodiment, the first preset value is smaller than the second preset value, and the second preset value may be the rated output voltage value of the rechargeable battery 200, or slightly greater than the rated output voltage value of the rechargeable battery 200 A voltage value, for example, 1.2 times the rated output voltage value of the rechargeable battery 200 .

Please also refer to FIG. 2 . In other embodiments, the switch unit 40 may also be a switch chip integrated with a multi-way switch, and the power output terminal 10 may be a parallel port. Therefore, the number of the switch unit 40 and the power output terminal 10 can be reduced to one, and it is only necessary to connect each port of the power output terminal 10 to each switch of the switch unit 40 .

It can be understood that the above-mentioned charging control circuit 100 can be installed in a casing (not shown in the figure), and further constitute a charging device together with the casing. In addition, the charging device and the plurality of rechargeable batteries 200 together constitute a charging system.

Please also refer to FIG. 3 , it can be understood that the charging system can be applied to a mobile device 300 . The mobile device 300 may be a vehicle, a ship, or the like. The mobile device 300 also includes a power device 301 . The charging system is electrically connected to the power device 301 to provide electric energy for the power device 301 .

Please also refer to FIG. 4 , in one embodiment, the mobile device 300 is an unmanned aerial vehicle. The power unit 301 includes an electric regulator 303 , a motor 305 and a propeller 307 . The ESC 303 is electrically connected to the motor 305 for controlling the rotation speed of the motor 305 . The propeller 307 is mounted on the motor 305 and used to drive the UAV 300 to fly under the drive of the motor 305 . The charging system is electrically connected to the ESC 303 to provide electric energy for the power device 301 .

The above is only an embodiment of the utility model, and does not limit the patent scope of the utility model. Any equivalent structure or equivalent process conversion made by using the utility model specification and accompanying drawings, or directly or indirectly used in other Related technical fields are all included in the patent protection scope of the present utility model in the same way.

Claims (24)

1. A charge control circuit, characterized in that the charge control circuit comprises: charging unit; There are multiple power output terminals, which are respectively used to connect to multiple rechargeable batteries and charge the multiple rechargeable batteries; and a control unit electrically connected to the charging unit; Wherein, the control unit controls the charging unit to charge the multiple batteries according to a first charging mode, and the first charging mode is: according to the order of battery voltages of the multiple rechargeable batteries from high to low The plurality of rechargeable batteries are respectively charged to a first preset value, and then all the rechargeable batteries are recharged simultaneously to a second preset value, and the first preset value is smaller than the second preset value. 2. The charging control circuit according to claim 1, wherein the control unit is one of a field programmable gate array, a micro-control chip embedded with a control program, or a single-chip microcomputer. 3. The charging control circuit according to claim 1, wherein the charging control circuit further comprises: a switch unit, the switch unit is connected between the charging unit and the plurality of power output terminals; and a mode switching unit electrically connected to the control unit; Wherein, the control unit switches to the first charging mode or the second charging mode according to the switching signal sent by the mode switching unit, and outputs a corresponding switching signal to the switching unit, and the second charging mode is: Charge the multiple rechargeable batteries sequentially according to the battery voltage of the multiple rechargeable batteries from high to low; the switch unit disconnects or connects the charging unit and the multiple rechargeable batteries according to the switch The electrical connection between the output terminals of the power supply. 4. The charging control circuit according to claim 3, wherein the switch unit is a relay switch; or The switch unit is a MOS tube, the source of the MOS tube is electrically connected to the charging unit, the drain of the MOS tube is electrically connected to the corresponding power output terminal, and the gate of the MOS tube is electrically connected to the control unit; or The switch unit is an NPN triode, the collector of the NPN triode is electrically connected to the charging unit, the emitter is electrically connected to the corresponding power output terminal, and the base is electrically connected to the control unit. 5. The charging control circuit according to claim 3, wherein the mode switching unit includes a button, and the switching signal is output by operating the button; or The mode switching unit includes an automatic switching circuit for automatically outputting the switching signal after detecting a preset trigger condition. 6. The charging control circuit according to claim 3, further comprising a voltage acquisition unit, the voltage acquisition unit is connected between the charging unit and the switching unit, and is connected to the The control unit; the voltage acquisition unit is used to acquire the voltage values of the plurality of rechargeable batteries, and the control unit controls the plurality of power supply output terminals and The charging unit is turned on or off. 7. The charging control circuit according to claim 6, wherein the control unit controls the plurality of power supply output terminals to be connected to the charging unit one by one through the switching unit, so as to control the voltage acquisition unit Collect the battery voltage of each rechargeable battery; Or/and, in the first charging mode, the control unit further controls the power output terminal corresponding to the rechargeable battery with the largest voltage value among the detected battery voltages to be turned on, while the other power output terminals are powered off, so as to making the charging unit charge the rechargeable battery with the highest battery voltage to the first preset value. 8. The charging control circuit according to claim 1, wherein the charging unit sequentially charges the plurality of rechargeable batteries to a first preset value by means of constant current charging; Or/and, the charging unit charges the plurality of rechargeable batteries from the first preset value to a second preset value by means of constant voltage charging. 9. A charging device, characterized by comprising a casing and a charging control circuit installed in the casing, wherein the charging control circuit includes: charging unit; There are multiple power output terminals, which are respectively used to connect to multiple rechargeable batteries and charge the multiple rechargeable batteries; and a control unit electrically connected to the charging unit; Wherein, the control unit controls the charging unit to charge the multiple batteries according to a first charging mode, and the first charging mode is: according to the order of battery voltages of the multiple rechargeable batteries from high to low The plurality of rechargeable batteries are respectively charged to a first preset value, and then all the rechargeable batteries are recharged simultaneously to a second preset value, and the first preset value is smaller than the second preset value. 10. The charging device according to claim 9, wherein the control unit is one of a field programmable gate array, a micro-control chip embedded with a control program, or a single-chip microcomputer. 11. The charging device according to claim 9, wherein the charging control circuit further comprises: a switch unit, the switch unit is connected between the charging unit and the plurality of power output terminals; and a mode switching unit electrically connected to the control unit; Wherein, the control unit switches to the first charging mode or the second charging mode according to the switching signal sent by the mode switching unit, and outputs a corresponding switching signal to the switching unit, and the second charging mode is: Charge the multiple rechargeable batteries sequentially according to the battery voltage of the multiple rechargeable batteries from high to low; the switch unit disconnects or connects the charging unit and the multiple rechargeable batteries according to the switch The electrical connection between the output terminals of the power supply. 12. The charging device according to claim 11, wherein the switch unit is a relay switch; or The switch unit is a MOS tube, the source of the MOS tube is electrically connected to the charging unit, the drain of the MOS tube is electrically connected to the corresponding power output terminal, and the gate of the MOS tube is electrically connected to the control unit; or The switch unit is an NPN triode, the collector of the NPN triode is electrically connected to the charging unit, the emitter is electrically connected to the corresponding power output terminal, and the base is electrically connected to the control unit. 13. The charging device according to claim 11, wherein the mode switching unit comprises a button, and the switching signal is output by operating the button; or The mode switching unit includes an automatic switching circuit for automatically outputting the switching signal after detecting a preset trigger condition. 14. The charging device according to claim 11, wherein the charging control circuit further comprises a voltage acquisition unit connected between the charging unit and the switching unit, and connected to the A control unit; the voltage acquisition unit is used to acquire the voltage values of the plurality of rechargeable batteries, and the control unit controls the plurality of power output terminals and the plurality of power supply output terminals through the switch unit according to the voltage values acquired by the voltage acquisition unit The conduction or disconnection of the charging unit. 15. The charging device according to claim 14, wherein the control unit controls the plurality of power supply output terminals to be connected to the charging unit one by one through the switching unit, so as to control the voltage acquisition unit to collect the battery voltage of each rechargeable battery; Or/and, in the first charging mode, the control unit further controls the power output terminal corresponding to the rechargeable battery with the largest voltage value among the detected battery voltages to be turned on, while the other power output terminals are powered off, so as to making the charging unit charge the rechargeable battery with the highest battery voltage to the first preset value. 16. The charging device according to claim 9, wherein the charging unit sequentially charges the plurality of rechargeable batteries to a first preset value by means of constant current charging; Or/and, the charging unit charges the plurality of rechargeable batteries from the first preset value to a second preset value by means of constant voltage charging. 17. A charging system, characterized in that the charging system includes a plurality of rechargeable batteries and a charging control circuit for charging the plurality of rechargeable batteries, wherein the charging control circuit includes: charging unit; There are multiple power output terminals, which are respectively used to connect to the multiple rechargeable batteries and charge the multiple rechargeable batteries; and a control unit electrically connected to the charging unit; Wherein, the control unit controls the charging unit to charge the multiple batteries according to a first charging mode, and the first charging mode is: according to the order of battery voltages of the multiple rechargeable batteries from high to low The plurality of rechargeable batteries are respectively charged to a first preset value, and then all the rechargeable batteries are recharged simultaneously to a second preset value, and the first preset value is smaller than the second preset value. 18. The charging system according to claim 17, wherein the control unit is one of a field programmable gate array, a micro-control chip embedded with a control program, or a single-chip microcomputer. 19. The charging system according to claim 17, wherein the charging control circuit further comprises: a switch unit, the switch unit is connected between the charging unit and the plurality of power output terminals; and a mode switching unit electrically connected to the control unit; Wherein, the control unit switches to the first charging mode or the second charging mode according to the switching signal sent by the mode switching unit, and outputs a corresponding switching signal to the switching unit, and the second charging mode is: Charge the multiple rechargeable batteries sequentially according to the battery voltage of the multiple rechargeable batteries from high to low; the switch unit disconnects or connects the charging unit and the multiple rechargeable batteries according to the switch The electrical connection between the output terminals of the power supply. 20. The charging system according to claim 19, wherein the switch unit is a relay switch; or The switch unit is a MOS tube, the source of the MOS tube is electrically connected to the charging unit, the drain of the MOS tube is electrically connected to the corresponding power output terminal, and the gate of the MOS tube is electrically connected to the control unit; or The switch unit is an NPN triode, the collector of the NPN triode is electrically connected to the charging unit, the emitter is electrically connected to the corresponding power output terminal, and the base is electrically connected to the control unit. 21. The charging system according to claim 19, wherein the mode switching unit comprises a button, and the switching signal is output by operating the button; or The mode switching unit includes an automatic switching circuit for automatically outputting the switching signal after detecting a preset trigger condition. 22. The charging system according to claim 19, wherein the charging control circuit further comprises a voltage acquisition unit connected between the charging unit and the switching unit, and connected to the A control unit; the voltage acquisition unit is used to acquire the voltage values of the plurality of rechargeable batteries, and the control unit controls the plurality of power output terminals and the plurality of power supply output terminals through the switch unit according to the voltage values acquired by the voltage acquisition unit The conduction or disconnection of the charging unit. 23. The charging system according to claim 22, wherein the control unit controls the multiple power supply output terminals to be connected to the charging unit one by one through the switching unit, so as to control the voltage acquisition unit to collect the battery voltage of each rechargeable battery; Or/and, in the first charging mode, the control unit further controls the power output terminal corresponding to the rechargeable battery with the largest voltage value among the detected battery voltages to be turned on, while the other power output terminals are powered off, so as to making the charging unit charge the rechargeable battery with the highest battery voltage to the first preset value. 24. The charging system according to claim 21, wherein the charging unit sequentially charges the plurality of rechargeable batteries to a first preset value by means of constant current charging; Or/and, the charging unit charges the plurality of rechargeable batteries from the first preset value to a second preset value by means of constant voltage charging.