Battery series discharging and parallel charging circuit

Abstract

The utility model discloses a battery series discharging and parallel charging circuit, which comprises a main control board, a plurality of batteries and a load, and is characterized in that the main control board is electrically connected with the load through the batteries; the batteries are sequentially connected in series end to end, a series battery pack formed by the batteries is grounded through a load, the positive electrode of each battery is electrically connected with a first switch, the movable end of the first switch is electrically connected with the positive electrode of the battery, the first switch is provided with two fixed ends, and one fixed end is electrically connected with the power output end of the main control board. All the batteries are connected in parallel without distinguishing the number of the batteries; in the parallel connection process of all the batteries, when the control switch is switched off, the voltages of all the batteries can be mutually balanced, and the problem of voltage difference generated in the series discharge process of the batteries can be solved; and overvoltage protection in the charging process of the whole circuit is simplified.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates to a battery series discharge and parallel charge circuit. Background Art

[0002] In the existing battery module, the connection mode of the batteries is relatively single, and series or parallel adjustment cannot be performed. During charging, if the battery pack is in series mode, the charging voltage will increase due to the increase in the number of series-connected batteries, resulting in unstable charging or even too high charging voltage. During discharging, the battery needs to provide a relatively large output voltage to drive electronic components or electrical appliances.

[0003] In summary, a battery series discharge and parallel charge circuit is designed. Summary of the Invention

[0004] The utility model aims to overcome the above deficiencies and provides a battery series discharge and parallel charge circuit.

[0005] The utility model realizes the above object through the following technical solutions:

[0006] A battery series discharge and parallel charge circuit includes a main control board, a plurality of batteries and a load. The main control board is electrically connected to the load through the batteries;

[0007] The batteries are connected in series end to end in sequence. The series battery group composed of the batteries is grounded through the load. A first switch is electrically connected to the positive electrode of each battery. The moving end of the first switch is electrically connected to the positive electrode of the battery. The first switch has two fixed ends. One of the fixed ends is electrically connected to the power output end of the main control board, and the other fixed end is electrically connected to the negative electrode of the serially connected battery. The negative electrodes of the batteries are all grounded to the ground end of the main control board through a second switch. The first switch and the second switch are respectively electrically connected to the output ends of the main control board.

[0008] Preferably, a current adjustment module is electrically connected to the power output end of the main control board. The control end of the current adjustment module is electrically connected to the control end of the main control board through a control switch. The input end of the current adjustment module is electrically connected to the power output end of the main control board. The output end of the current adjustment module is electrically connected to the second contact of each first switch.

[0009] Preferably, a current-limiting voltage-dividing resistor is arranged between the second switch and the ground end of the main control board. The current-limiting voltage-dividing resistor is composed of a plurality of resistors connected in parallel. The battery is electrically connected to the current detection end of the main control board through the second switch.

[0010] Preferably, the main control board is electrically connected to a charging port. The main control board judges whether to enter the charging state or the discharging state by detecting the input voltage of the charging port.

[0011] Preferably, the load is grounded through a load switch. In the discharge state, the load switch controls the operation and stop of the load.

[0012] Preferably, the main control board is electrically connected to a battery cell number selection port. One end of the battery cell number selection port is grounded, and the other ports of the battery cell number selection port are respectively electrically connected to other signal input ends of the main control board. We can set the number of batteries through the battery cell number selection port. For example, if the grounded end GND of the battery cell number selection port is connected to the B1 end of the battery cell number selection port, it means there is only 1 battery. If the grounded end GND of the battery cell number selection port is connected to the B6 end of the grounded end of the battery cell number selection port, it means there are only 6 batteries, and so on. The main control board obtains the number of batteries by detecting the states of the B1~Bn ports. Assume the number of batteries is N.

[0013] The beneficial effects of the present utility model are as follows: In this battery series discharge and parallel charge circuit:

[0014] During charging, since all batteries are in parallel, the adapter voltage can be unified to 4.2V, and there is no need to distinguish the number of battery cells.

[0015] During the process of all batteries being in parallel, when the control switch is disconnected, all batteries can balance the voltage with each other, which is beneficial to solving the problem of voltage difference generated during the series discharge process of the batteries.

[0016] It can simplify the overvoltage protection in the charging process of the entire circuit, thereby improving system safety.

[0017] An additional current regulation module is added. Combining with software algorithms, it can achieve the problem of overcurrent charging prevention, extend the service life of the battery cells, and improve system safety.

[0018] The system can be compatible with the selection of the number of batteries, facilitating compatibility with different product requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present utility model will be described by way of examples with reference to the accompanying drawings, where:

[0020] Figure 1 is a schematic structural diagram of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] Now, the present utility model will be further described in detail with reference to the accompanying drawings. These drawings are all simplified schematic diagrams, only illustrating the basic structure of the present utility model in a schematic manner, so they only show the components related to the present utility model.

[0022] A battery series discharge and parallel charge circuit includes a main control board, a plurality of batteries, and a load. The main control board is electrically connected to the load through the batteries;

[0023] The batteries are connected in series end to end, and the series battery pack composed of each battery is grounded through a load. The positive electrodes of the batteries are all electrically connected to a first switch. The moving end of the first switch is electrically connected to the positive electrode of the battery. The first switch has two fixed ends, one of which is electrically connected to the power output terminal of the main control board, and the other is electrically connected to the negative electrode of the serially connected battery. The negative electrodes of the batteries are all grounded to the ground terminal of the main control board through a second switch. The first switch and the second switch are respectively electrically connected by the output terminals of the main control board.

[0024] Figure 1 As shown, when entering the charging state, the control switch is closed, and the S1~S10 switches (the first switch and the second switch) are connected to the contact 2 (the fixed end for connecting when the batteries are in parallel), achieving the effect of all batteries being in parallel (that is: the positive electrodes of all batteries are connected to each other, and the negative electrodes are connected to each other);

[0025] When entering the discharging state, the control switch is disconnected, and the S1~S10 (the first switch and the second switch) are connected to the contact 1 (the fixed end for connecting when the batteries are in series), achieving the effect of each battery being connected in series with each other (all batteries are connected positive to negative in sequence).

[0026] Specifically, the power output terminal of the main control board is electrically connected to a current adjustment module. The control terminal of the current adjustment module is electrically connected to the control terminal of the main control board through the control switch. The input terminal of the current adjustment module is electrically connected to the power output terminal of the main control board, and the output terminal of the current adjustment module is electrically connected to the second contact of each first switch.

[0027] Specifically, a current-limiting voltage-dividing resistor is provided between the second switch and the ground terminal of the main control board. The current-limiting voltage-dividing resistor is composed of multiple resistors in parallel. The battery is electrically connected to the current detection terminal of the main control board through the second switch.

[0028] Specifically, the main control board is electrically connected to a charging port. The main control board determines whether to enter the charging state or the discharging state by detecting the input voltage of the charging port.

[0029] Specifically, the load is grounded through a load switch. In the discharging state, the load switch controls the operation and stop of the load.

[0030] Specifically, the main control board is electrically connected to a battery cell quantity selection port. One end of the battery cell quantity selection port is grounded, and the other ports of the battery cell quantity selection port are respectively electrically connected to other signal input ends of the main control board. We can set the number of batteries through the battery cell quantity selection port. For example, if the grounded end GND of the battery cell quantity selection port is connected to the B1 end of the battery cell quantity selection port, it means there is only 1 battery. If the grounded end GND of the battery cell quantity selection port is connected to the B6 end of the grounded end of the battery cell quantity selection port, it means there are only 6 batteries, and so on. The main control board obtains the number of batteries by detecting the states of the B1~Bn ports. Assume the number of batteries is N.

[0031] The usage principles of the battery series discharge and parallel charge circuit are as follows:

[0032] The charging current of each battery is limited and cannot exceed the maximum charging current that the battery can withstand, assumed to be Imax. However, the output current of the charger cannot be infinitely large either. Assume the maximum output current is: Iin; the unit is: A.

[0033] In practical applications, the number of batteries in a product is limited. To be compatible with multiple batteries, the main control board has added a battery quantity selection port.

[0034] The current regulation module only works in the charging state, and its main function is: to regulate the magnitude of the current in the charging circuit.

[0035] R1~R4 are current-limiting and voltage-dividing resistors. The purpose is: the main control board detects the voltage Ud at point D1 in the charge / discharge circuit through the ADC_IN port. According to the formula: U = I*R, where U = Ud, R is the parallel total resistance value of R1~R4, and Id is the loop current.

[0036] Thus, we can obtain Formula 1

[0037] Thus, the total loop current Id is obtained;

[0038] The DAC_Vout (i.e., the current detection end) of the main control board can output an analog voltage Ux = 0~5V, and then connect it to the Vin end of the current regulation module. The main control board controls the current regulation module by adjusting the value of the voltage Ux output from the DAC_Vout port, so as to achieve the purpose of adjusting the charging current magnitude;

[0039] The specific control algorithm is as follows:

[0040] Assume that, in the charging state, the current we expect to flow through each battery is , the unit is: A, and its value range is 0 < Ia < Imax;

[0041] Then we can obtain: Iin* = Formula 2

[0042] where N is the total number of batteries, is a function of the variable x, and the value range is: [0, 1]; In practical applications, there are several situations:

[0043] When = this is an ideal state, and at this time, it can be obtained that: = 1;

[0044] When < this is because the maximum output current of the charger is limited, and at this time: = 1 is sufficient, and the adapter charges the battery with the maximum current;

[0045] When > at this time, it is necessary to adjust the value of to make it satisfy the equality relationship of Formula 2;

[0046] It can be known from the system relationship that:

[0047] , where a, b, and c are constants, obtained through testing according to the actual situation;

[0048] The analog voltage value at the current detection end of the main control board is inversely proportional to the charging circuit current and the relationship formula can be obtained;

[0049] .

[0050] Based on the inspiration of the present utility model, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this utility model. The technical scope of this utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A battery series discharge and parallel charge circuit, characterized in that: It includes a main control board, several batteries and a load, and the main control board is electrically connected to the load through the batteries; The batteries are connected in series end to end in sequence. The series battery pack composed of the batteries is grounded through the load. A first switch is electrically connected to the positive electrode of each battery. The moving end of the first switch is electrically connected to the positive electrode of the battery. The first switch has two fixed ends. One of the fixed ends is electrically connected to the power output end of the main control board, and the other fixed end is electrically connected to the negative electrode of the series-connected battery. The negative electrodes of the batteries are all grounded to the ground end of the main control board through a second switch. The first switch and the second switch are respectively electrically connected to the output ends of the main control board.

2. The battery series discharge and parallel charge circuit according to claim 1, wherein: The power output end of the main control board is electrically connected to a current adjustment module. The control end of the current adjustment module is electrically connected to the control end of the main control board through a control switch. The input end of the current adjustment module is electrically connected to the power output end of the main control board. The output end of the current adjustment module is electrically connected to the second contact of each first switch.

3. The battery series discharge and parallel charge circuit according to claim 1, wherein: A current-limiting voltage-dividing resistor is provided between the second switch and the ground end of the main control board. The battery is electrically connected to the current detection end of the main control board through the second switch.

4. The battery series discharge and parallel charge circuit according to claim 1, wherein: The main control board is electrically connected to a charging port.

5. The battery series discharge and parallel charge circuit according to claim 1, characterized in that: The load is grounded through a load switch.

6. The battery series discharge and parallel charge circuit according to claim 1, wherein: The main control board is electrically connected to a cell number selection port. One end of the cell number selection port is grounded, and the other ports of the cell number selection port are respectively electrically connected to the other signal input ends of the main control board.

Images