CN207098704U - The circuit and battery protection system balanced for adjusting two section voltage of serially-connected cells - Google Patents

Abstract

It is used to adjust two section voltage of serially-connected cells balanced circuit and battery protection system the utility model discloses a kind of; the first battery and the second battery including concatenation; first end of the first electronic switch is connected between the positive pole of external-connected port and the first battery; second end of the first electronic switch is connected with the first end of the second electronic switch; the control terminal of first electronic switch and the second electronic switch is connected with controller; one end of first resistor is connected between the first battery and the second battery, another to terminate between the first electronic switch and the second electronic switch；First voltage detection circuit is connected between external-connected port and the first battery, and second voltage detection circuit is connected between the first battery and the second battery, and the output end of first voltage detection circuit and second voltage detection circuit is connected with controller.The utility model can prevent that two section series-connected cells voltage difference value in charge and discharge process is excessive, ensure the operating efficiency of battery, extend the service life of battery, improve security.

Description

A circuit for adjusting the voltage balance of two series batteries and a battery pack protection system

technical field

The utility model particularly relates to a circuit and a battery group protection system for adjusting the voltage balance of two series batteries.

Background technique

During the charging and discharging process of the battery pack, the working voltage of each battery is generally not equal, so it is very easy to overcharge or overdischarge a single or multiple batteries, which will seriously affect the service life of the battery and even cause safety problems.

Contents of the invention

The purpose of this utility model is to provide a circuit and a battery pack protection system for adjusting the voltage balance of two series-connected batteries, which can prevent the voltage difference between the two series-connected batteries during charging and discharging. If it is too large, it will ensure that the charging voltage or discharging voltage of the two batteries connected in series is finally the same, so as to ensure the working efficiency of the battery, prolong the service life of the battery, and improve the safety.

In order to solve the problems of the technologies described above, the technical solution adopted in the utility model is:

A circuit for adjusting the voltage balance of two batteries connected in series, including a first battery and a second battery connected in series to form a battery pack, the negative pole of the first battery is electrically connected to the positive pole of the second battery, and the positive pole of the first battery is connected to the battery The external port of the group is electrically connected, the negative pole of the second battery is connected to the digital ground, and its structural feature is that it also includes a first electronic switch, a second electronic switch, a controller, a first resistor, a first voltage detection circuit and a second voltage detection circuit , the first terminal of the first electronic switch is connected between the external port and the positive pole of the first battery, the second terminal of the first electronic switch is electrically connected with the first terminal of the second electronic switch, and the second terminal of the second electronic switch connected to the analog ground, the control terminal of the first electronic switch and the control terminal of the second electronic switch are both electrically connected to the controller, one terminal of the first resistor is connected between the negative pole of the first battery and the positive pole of the second battery, and the first resistor The other end of the first electronic switch is connected between the second end of the first electronic switch and the first end of the second electronic switch; the detection end of the first voltage detection circuit is connected between the external port and the positive pole of the first battery, and the second voltage detection circuit The detection terminal of the circuit is connected between the negative pole of the first battery and the positive pole of the second battery, and the output terminals of the first voltage detection circuit and the second voltage detection circuit are electrically connected with the controller.

With the above structure, the initial states of the first electronic switch and the second electronic switch are both off. The total voltage of the battery pack is detected by the first voltage detection circuit, the terminal voltage of the second battery is detected by the second voltage detection circuit, and the difference between the total voltage and the terminal voltage is the terminal voltage of the first battery.

When charging, when the difference between the terminal voltage of the first battery and the terminal voltage of the second battery exceeds the preset range, if the terminal voltage of the first battery is greater than the terminal voltage of the second battery, the controller controls the second battery Once the electronic switch is closed, the total charging current I will be divided into two parts (I1 and I2), among which the partial current I1 will charge the first battery, and the partial current I2 will be consumed on the first resistor, while the total current I will charge the second battery. Until the voltage difference between the two batteries is within the prescribed range, the controller controls the first electronic switch to be turned off, and the equalizing circuit stops working. If the terminal voltage of the first battery is lower than the terminal voltage of the second battery, the controller will control the second electronic switch to close, and the total current I will directly charge the first battery, and then the total charging current I will be divided into two parts (I1 and I2) , wherein the divided current I1 is consumed on the first resistor, and the divided current I2 charges the second battery until the voltage difference between the two batteries is within the specified range, the controller controls the second electronic switch to be turned off, and the equalizing circuit stops working.

When discharging, the adjustment process of the terminal voltage difference between the two batteries is similar to the charging process.

Through the above circuit, during the charging and discharging process of the battery pack, any excessive current can be automatically consumed through the first resistor, thereby adjusting the terminal voltage of the two series-connected batteries, which can prevent the voltage of the two series-connected batteries during the charging and discharging process. If the voltage difference is too large, the charging voltage or discharging voltage of the two series-connected batteries is finally consistent, which ensures the working efficiency of the battery, prolongs the service life of the battery, and improves safety.

As a preferred manner, the first voltage detection circuit includes a second resistor and a first sampling circuit, one end of the second resistor is connected between the external port and the positive pole of the first battery, and the other end of the second resistor passes through the first The sampling circuit is electrically connected to the controller; the second voltage detection circuit includes a third resistor and a second sampling circuit, one end of the third resistor is connected between the negative pole of the first battery and the positive pole of the second battery, and the third resistor The other end is electrically connected to the controller through the second sampling circuit.

As a preferred manner, the first electronic switch is a first MOS transistor, the source of the first MOS transistor is the first end of the first electronic switch, and the drain of the first MOS transistor is the second end of the first electronic switch, The gate of the first MOS transistor is the control terminal of the first electronic switch.

As a preferred manner, the second electronic switch is a second MOS transistor, the source of the second MOS transistor is the first end of the second electronic switch, and the drain of the second MOS transistor is the second end of the second electronic switch, The gate of the second MOS transistor is the control terminal of the second electronic switch.

As a preferred manner, the enabling terminal of the controller is grounded and active at low level.

Further, the first electronic switch, the second electronic switch, the controller, the first sampling circuit, and the second sampling circuit are integrated into an integrated chip.

All components are integrated into an integrated chip, which is convenient for connection and use.

Based on the same inventive idea, the utility model also provides a battery pack protection system, including the circuit for adjusting the voltage balance of two series batteries, and a charging and discharging protection integrated circuit electrically connected to the battery pack .

With the above structure, the battery pack can be protected to prevent potential safety hazards: when the battery pack is charged by an external power source, the charge and discharge protection integrated circuit will monitor whether the battery pack voltage is overcharged. If the battery holder voltage exceeds the maximum value, the charging The discharge protection integrated circuit controls the external power supply not to charge the battery pack. When the battery pack is discharged to the outside, if over-current discharge or short circuit occurs, the charge and discharge protection integrated circuit can quickly cut off the discharge circuit to protect the battery pack in series. When the voltage of the battery pack is lower than the minimum value, the charge and discharge protection integrated circuit will block the discharge of the battery pack.

The utility model can prevent the voltage difference between two series batteries from being too large during the charging and discharging process, ensure that the charging voltage or discharge voltage of the two series batteries is finally consistent, and prevent the battery pack from overcharging, overdischarging, overcurrent or short circuit. , to ensure the working efficiency of the battery, prolong the service life of the battery, and improve safety.

Description of drawings

Figure 1 is a circuit structure for adjusting the voltage balance of two series-connected batteries.

Fig. 2 is a schematic structural diagram of the battery pack protection system.

Among them, 1 is the battery pack, 2 is the controller, 3 is the first voltage detection circuit, 31 is the first sampling circuit, 4 is the second voltage detection circuit, 41 is the second sampling circuit, 5 is the integrated chip, 6 is the 7 is a charge-discharge protection integrated circuit, BT1 is the first battery, BT2 is the second battery, B+ is an external port, Q1 is the first electronic switch, and Q2 is the second electronic switch. R1 is the first resistor, R2 is the second resistor, and R3 is the third resistor.

Detailed ways

As shown in Figure 1, the circuit for adjusting the voltage balance of two batteries in series includes a first battery BT1 and a second battery BT2 connected in series to form a battery pack 1, the negative pole of the first battery BT1 is electrically connected to the positive pole of the second battery BT2 , the positive pole of the first battery BT1 is electrically connected to the external port B+ of the battery pack 1, the negative pole of the second battery BT2 is connected to the digital ground, and its structural feature is that it also includes a first electronic switch Q1, a second electronic switch Q2, a controller 2, The first resistor R1, the first voltage detection circuit 3 and the second voltage detection circuit 4, the first terminal of the first electronic switch Q1 is connected between the external port B+ and the positive pole of the first battery BT1, the first terminal of the first electronic switch Q1 The two terminals are electrically connected to the first terminal of the second electronic switch Q2, the second terminal of the second electronic switch Q2 is connected to the analog ground, the control terminal of the first electronic switch Q1 and the control terminal of the second electronic switch Q2 are connected to the controller 2 Electrically connected, one end of the first resistor R1 is connected between the negative pole of the first battery BT1 and the positive pole of the second battery BT2, and the other end of the first resistor R1 is connected between the second end of the first electronic switch Q1 and the second electronic switch Q1. Between the first terminals of Q2; the detection terminal of the first voltage detection circuit 3 is connected between the external port B+ and the positive pole of the first battery BT1, and the detection terminal of the second voltage detection circuit 4 is connected between the negative pole of the first battery BT1 and the positive pole of the first battery BT1. Between the positive poles of the second battery BT2 , the output terminals of the first voltage detection circuit 3 and the second voltage detection circuit 4 are both electrically connected to the controller 2 .

The first voltage detection circuit 3 includes a second resistor R2 and a first sampling circuit 31, one end of the second resistor R2 is connected between the external port B+ and the positive pole of the first battery BT1, and the other end of the second resistor R2 passes through the first A sampling circuit 31 is electrically connected to the controller 2; the second voltage detection circuit 4 includes a third resistor R3 and a second sampling circuit 41, and one end of the third resistor R3 is connected to the negative pole of the first battery BT1 and the second battery BT2 The other end of the third resistor R3 is electrically connected to the controller 2 through the second sampling circuit 41 .

The first electronic switch Q1 is a first MOS transistor, the source of the first MOS transistor is the first end of the first electronic switch Q1, the drain of the first MOS transistor is the second end of the first electronic switch Q1, and the first MOS The gate of the tube is the control terminal of the first electronic switch Q1.

The second electronic switch Q2 is a second MOS transistor, the source of the second MOS transistor is the first end of the second electronic switch Q2, the drain of the second MOS transistor is the second end of the second electronic switch Q2, and the second MOS The gate of the tube is the control terminal of the second electronic switch Q2.

The enabling terminal of the controller 2 is grounded and active at low level. The ground terminal of the controller 2 is connected to the digital ground.

The first electronic switch Q1 , the second electronic switch Q2 , the controller 2 , the first sampling circuit 31 , and the second sampling circuit 41 are integrated into an integrated chip 5 .

The first end of the first electronic switch Q1 is the first pin of the integrated chip 5, the second end of the first electronic switch Q1 leads to the first pin of the integrated chip 5, and the first end of the second electronic switch Q2 leads to the first pin of the integrated chip 5. The third pin, the second end of the second electronic switch Q2 leads to the fourth pin of the integrated chip 5, the input end of the second sampling circuit 41 leads to the fifth pin of the integrated chip 5, and the ground terminal of the controller 2 leads to the integrated chip 5. The sixth pin, the enable end of the controller 2 leads to the seventh pin of the integrated chip 5 , and the input end of the first sampling circuit 31 leads to the eighth pin of the integrated chip 5 .

As shown in FIG. 2 , the battery pack protection system includes the circuit 6 for adjusting the voltage balance of two series-connected batteries, and also includes a charging and discharging protection integrated circuit 7 electrically connected to the battery pack 1 .

Embodiments of the present utility model have been described above in conjunction with the accompanying drawings, but the present utility model is not limited to the above-mentioned specific implementation, and the above-mentioned specific implementation is only illustrative, rather than limiting, and those of ordinary skill in the art Under the enlightenment of the utility model, personnel can also make many forms without departing from the purpose of the utility model and the scope protected by the claims, and these all belong to the protection scope of the utility model.

Claims (7)

1. a kind of be used to adjust the balanced circuit of two section voltage of serially-connected cells, including is concatenated into battery pack（1）The first battery （BT1）With the second battery（BT2）, the first battery（BT1）Negative pole and the second battery（BT2）Positive pole electrical connection, the first battery （BT1）Positive pole and battery pack（1）External-connected port（B+）Electrical connection, the second battery（BT2）Negative pole connect digitally, its feature It is, in addition to the first electronic switch（Q1）, the second electronic switch（Q2）, controller（2）, first resistor（R1）, first voltage Detect circuit（3）Circuit is detected with second voltage（4）, the first electronic switch（Q1）The first end be connected on external-connected port（B+）With One battery（BT1）Positive pole between, the first electronic switch（Q1）The second end and the second electronic switch（Q2）First end be electrically connected Connect, the second electronic switch（Q2）Second termination simulation ground, the first electronic switch（Q1）Control terminal and the second electronic switch （Q2）Control terminal and controller（2）Electrical connection, first resistor（R1）An end be connected on the first battery（BT1）Negative pole and Two batteries（BT2）Positive pole between, first resistor（R1）Another terminate at the first electronic switch（Q1）The second end and second Electronic switch（Q2）First end between；First voltage detects circuit（3）Detection terminate at external-connected port（B+）With the first electricity Pond（BT1）Positive pole between, second voltage detection circuit（4）Detection terminate at the first battery（BT1）Negative pole and second electricity Pond（BT2）Positive pole between, first voltage detection circuit（3）Circuit is detected with second voltage（4）Output end and controller （2）Electrical connection.

2. as claimed in claim 1 be used to adjust the balanced circuit of two section voltage of serially-connected cells, it is characterised in that described first Voltage detecting circuit（3）Including second resistance（R2）With the first sample circuit（31）, second resistance（R2）An end be connected on it is external Port（B+）With the first battery（BT1）Positive pole between, second resistance（R2）The other end pass through the first sample circuit（31）With Controller（2）Electrical connection；The second voltage detects circuit（4）Including 3rd resistor（R3）With the second sample circuit（41）, the Three resistance（R3）An end be connected on the first battery（BT1）Negative pole and the second battery（BT2）Positive pole between, 3rd resistor（R3） The other end pass through the second sample circuit（41）With controller（2）Electrical connection.

3. as claimed in claim 1 or 2 be used to adjust the balanced circuit of two section voltage of serially-connected cells, it is characterised in that described First electronic switch（Q1）For the first metal-oxide-semiconductor, the source electrode of the first metal-oxide-semiconductor is the first electronic switch（Q1）First end, the first MOS The drain electrode of pipe is the first electronic switch（Q1）The second end, the grid of the first metal-oxide-semiconductor is the first electronic switch（Q1）Control terminal.

4. as claimed in claim 1 or 2 be used to adjust the balanced circuit of two section voltage of serially-connected cells, it is characterised in that described Second electronic switch（Q2）For the second metal-oxide-semiconductor, the source electrode of the second metal-oxide-semiconductor is the second electronic switch（Q2）First end, the 2nd MOS The drain electrode of pipe is the second electronic switch（Q2）The second end, the grid of the second metal-oxide-semiconductor is the second electronic switch（Q2）Control terminal.

5. as claimed in claim 1 or 2 be used to adjust the balanced circuit of two section voltage of serially-connected cells, it is characterised in that described Controller（2）Enable Pin ground connection and for low level it is effective.

6. as claimed in claim 2 be used to adjust the balanced circuit of two section voltage of serially-connected cells, it is characterised in that described first Electronic switch（Q1）, the second electronic switch（Q2）, controller（2）, the first sample circuit（31）, the second sample circuit（41）It is integrated For integrated chip（5）.

7. a kind of battery protection system, including it is used to adjust two section series-connected cell electricity as described in any one of claim 1 to 6 Press balanced circuit（6）, it is characterised in that also include and the battery pack（1）The charge and discharge protecting integrated circuit of electrical connection （7）.