CN217508336U

CN217508336U - Battery protection circuit

Info

Publication number: CN217508336U
Application number: CN202221634694.0U
Authority: CN
Inventors: 张新林; 张亮; 高旭; 严寅辉; 李绍金
Original assignee: Wuhan Lanpu Intelligent Technology Co ltd
Current assignee: Wuhan Lanpu Intelligent Technology Co ltd
Priority date: 2022-06-28
Filing date: 2022-06-28
Publication date: 2022-09-27
Anticipated expiration: 2032-06-28

Abstract

The utility model relates to a battery protection circuit, the one end and the battery interface negative pole of current detection resistance are connected, the other end and the source electrode of first current switch MOS pipe of current detection resistance are connected, the drain electrode of first current switch MOS pipe is connected with the drain electrode of second current switch MOS pipe, the source electrode of second current switch MOS pipe is connected with the negative pole of electricity core, the one end and the common port of the drain electrode of first current switch MOS pipe and the drain electrode of second current switch MOS pipe of current limiting resistance are connected, the other end and the drain electrode of pre-charge discharge switch of current limiting resistance are connected, the source electrode of pre-charge discharge switch is connected with the negative pole of electricity core; when the battery is connected to the electric equipment again, the current can pass through the pre-charging discharge switch, the current-limiting resistor, the first current switch MOS tube and the current detection resistor, the current-limiting resistor can reduce the current size, so that sparks cannot be generated at the battery interface, and after the short discharge time, the controller sends a high level to open the second current switch MOS tube again, so that the battery is recovered to be normally used.

Description

Battery protection circuit

Technical Field

The utility model relates to a battery protection equipment technical field, concretely relates to battery protection circuit.

Background

The existing rechargeable battery comprises a battery core and a protection plate. The controller of the engineering truck is internally provided with a capacitor, the capacitor plays the roles of electricity storage and discharge in work, the electric quantity of the capacitor is discharged in the production and transportation process, no residual electric quantity exists, when a battery is connected with circuits with the capacitor, such as the controller, a large amount of charges flow into the capacitor, and at the moment, the battery joint can emit 'sparks' instantly to generate the potential safety hazard of fire catching.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a battery protection circuit is provided to overcome not enough among the above-mentioned prior art.

The utility model provides an above-mentioned technical problem's technical scheme as follows: a battery protection circuit comprises a current detection resistor, a first current switch MOS tube, a second current switch MOS tube, a current limiting resistor and a pre-charging and discharging switch; one end of a current detection resistor is connected with the cathode of the battery interface, the other end of the current detection resistor is connected with the source electrode of a first current switch MOS tube, the drain electrode of the first current switch MOS tube is connected with the drain electrode of a second current switch MOS tube, the source electrode of the second current switch MOS tube is connected with the cathode of the battery cell, one end of a current limiting resistor is connected with the common end of the drain electrode of the first current switch MOS tube and the drain electrode of the second current switch MOS tube, the other end of the current limiting resistor is connected with the drain electrode of the pre-charging and discharging switch, and the source electrode of the pre-charging and discharging switch is connected with the cathode of the battery cell; the device further comprises a controller, and any one end of the current detection resistor, the grid electrode of the first current switch MOS tube, the grid electrode of the second current switch MOS tube and the grid electrode of the pre-charge and discharge switch are connected with the controller.

The beneficial effects of the utility model are that: the circuit is connected between the cathode of the battery core and the cathode of the battery interface, when the battery is normally used, current can pass through the current detection resistor, the first current switch MOS tube and the second current switch MOS tube, the current detection resistor can detect the magnitude of charging and discharging current, and when the current detection resistor detects that the current is overlarge, the controller sends low level to close the first current switch MOS tube and the second current switch MOS tube so as to protect the battery core; when the battery is unplugged, the current detection resistor does not detect that the current passes through, the controller sends a low level to close the second current switch MOS tube, meanwhile, the controller sends a high level to open the pre-charging and discharging switch, when the battery is connected to the electric equipment again, the current can pass through the pre-charging and discharging switch, the current limiting resistor, the first current switch MOS tube and the current detection resistor, the current limiting resistor can reduce the current, so that sparks cannot be generated at the interface of the battery, and after the battery is discharged for a short time, the controller sends a high level to open the second current switch MOS tube again, so that the battery is recovered to be normally used; the circuit can be applied to engineering vehicles.

On the basis of the technical scheme, the utility model discloses can also do following improvement.

Furthermore, the model of the controller is SH367309 front-end chip of the lithium battery.

Further, the current detection resistor includes two resistors R124 and R125 arranged in parallel.

Further, a voltage regulator tube and a resistor R105 are connected in parallel between the grid electrode and the source electrode of the pre-charging and discharging switch; the anode of the voltage-stabilizing tube is electrically connected with the source electrode of the pre-charging switch, and the cathode of the voltage-stabilizing tube is electrically connected with the grid electrode of the pre-charging switch.

And the capacitor is arranged between the source electrode of the first current switch MOS tube and the source electrode of the second current switch MOS tube.

Further, a resistor R58 and a resistor R68 are respectively arranged between the grid of the first current switch MOS tube and the grid of the second current switch MOS tube and the controller.

The anode of the diode is connected with the controller, and the cathode of the diode is connected with the grid of the pre-charging switch and the common end of the cathode of the voltage-stabilizing tube.

Drawings

Fig. 1 is a schematic diagram of the circuit structure of the present invention.

In the drawings, the components represented by the respective reference numerals are listed below:

1. the device comprises a current detection resistor, 2, a first current switch MOS tube, 3, a second current switch MOS tube, 4, a current limiting resistor, 5, a pre-charge and discharge switch, 6, a controller, 7, a voltage regulator tube, 8, a capacitor, 9 and a diode.

Detailed Description

The principles and features of the present invention are described below in conjunction with the following drawings, the examples given are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

Embodiment 1, as shown in fig. 1, a battery protection circuit includes a current detection resistor 1, a first current switch MOS transistor 2, a second current switch MOS transistor 3, and a current limiting resistor 4, which are sequentially connected in series between a negative electrode of a battery cell and a negative electrode of a battery interface; the drains of the first current switch MOS tube 2 and the second current switch MOS tube 3 are electrically connected with the drain of the pre-charge and discharge switch 5; the two poles of the current detection resistor 1, the grid of the first current switch MOS tube 2, the grid of the second current switch MOS tube 3 and the grid of the pre-charge and discharge switch 5 are respectively and electrically connected with the controller 6.

The circuit is connected between the cathode of the battery core and the cathode of the battery interface, when the battery is normally used, current can pass through the current detection resistor 1, the first current switch MOS tube 2 and the second current switch MOS tube 3, the current detection resistor 1 can detect the magnitude of charging and discharging current, and when the current detection resistor 1 detects that the current is too large, the controller 6 sends low level to close the first current switch MOS tube 2 and the second current switch MOS tube 3 so as to protect the battery core; when the battery is unplugged, the current detection resistor 1 does not detect that the current passes through, the controller 6 sends a low level to close the second current switch MOS tube 3, meanwhile, the controller 6 sends a high level to open the pre-charging and discharging switch 5, when the battery is connected to the electric equipment again, the current can pass through the pre-charging and discharging switch 5, the current limiting resistor 4, the first current switch MOS tube 2 and the current detection resistor 1, the current limiting resistor 4 can reduce the current, so that no spark is generated at the interface of the battery, and after the short discharging time, the controller 6 sends a high level to open the second current switch MOS tube 3 again, so that the battery is recovered to be normally used; in a specific implementation process, the circuit can be applied to engineering vehicles; the model of the current-limiting resistor 4 is RK-200-2515-5%, the models of the first current switch MOS tube 2 and the second current switch MOS tube 3 are Q-ZSD67106, and the model of the pre-charging and discharging switch is Q-BSS 123; the common end of the current detection resistor 1 and the negative electrode of the battery interface is grounded.

Example 2, as shown in fig. 1, this example is a further improvement on example 1, and specifically includes the following steps:

the controller 6 is an SH367309 lithium battery front-end chip and can be used for overcharge, overdischarge and overcurrent protection ICs of the lithium ion/lithium polymer rechargeable battery; can detect the overcharge, overdischarge, discharge overcurrent, charge overcurrent and battery pack balance of 3-5 series lithium ion/lithium polymer batteries.

Example 3, as shown in fig. 1, this example is a further improvement on example 1, and specifically includes the following steps:

the current detection resistor 1 comprises two resistors R124 and R125 which are arranged in parallel, and the arrangement of the two resistors avoids the situation that the current is large and the power of a single resistor is insufficient.

Example 4, as shown in fig. 1, this example is a further improvement on example 1, and specifically includes the following steps:

a voltage regulator tube 7 and a resistor R105 are connected in parallel between the grid and the source of the pre-charging and discharging switch 5; the anode of the voltage-regulator tube 7 is electrically connected with the source electrode of the pre-charging switch 5, and the cathode of the voltage-regulator tube 7 is electrically connected with the grid electrode of the pre-charging switch 5 to be used as a matching circuit of the pre-charging switch.

Example 5, as shown in fig. 1, this example is a further improvement on example 1, and specifically includes the following steps:

the circuit further comprises a capacitor 8 arranged between the source electrode of the first current switch MOS tube 2 and the source electrode of the second current switch MOS tube 3, and fluctuation of the level is reduced, wherein in specific implementation, the capacitor 8 adopts two capacitors C42 and C43 which are arranged in series.

Example 6, as shown in fig. 1, this example is a further improvement on example 1, and specifically includes the following steps:

a resistor R58 and a resistor R68 are respectively arranged between the gate of the first current switch MOS transistor 2 and the gate of the second current switch MOS transistor 3 and the controller 6, so as to prevent signal level overshoot.

Example 7, as shown in fig. 1, this example is a further improvement on example 4, and specifically includes the following steps:

the controller also comprises a diode 9, the anode of the diode 9 is connected with the controller 6, and the cathode of the diode 9 is connected with the grid of the pre-charge switch 5 and the common end of the cathode of the voltage regulator tube 7, so that negative voltage is prevented from reversely influencing the controller 6.

Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.

Claims

1. A battery protection circuit is characterized by comprising a current detection resistor (1), a first current switch MOS tube (2), a second current switch MOS tube (3), a current limiting resistor (4) and a pre-charging and discharging switch (5); one end of the current detection resistor (1) is connected with the negative electrode of a battery interface, the other end of the current detection resistor (1) is connected with the source electrode of the first current switch MOS tube (2), the drain electrode of the first current switch MOS tube (2) is connected with the drain electrode of the second current switch MOS tube (3), the source electrode of the second current switch MOS tube (3) is connected with the negative electrode of the battery cell, one end of the current limiting resistor (4) is connected with the common end of the drain electrode of the first current switch MOS tube (2) and the drain electrode of the second current switch MOS tube (3), the other end of the current limiting resistor (4) is connected with the drain electrode of the pre-charging and discharging switch (5), and the source electrode of the pre-charging and discharging switch (5) is connected with the negative electrode of the battery cell; the device is characterized by further comprising a controller (6), wherein any end of the current detection resistor (1), the grid electrode of the first current switch MOS tube (2), the grid electrode of the second current switch MOS tube (3) and the grid electrode of the pre-charge and discharge switch (5) are connected with the controller (6).

2. The battery protection circuit according to claim 1, wherein the controller (6) is of a type SH367309 lithium battery front end chip.

3. A battery protection circuit according to claim 1, characterized in that the current detection resistor (1) comprises two resistors R124 and R125 arranged in parallel.

4. The battery protection circuit according to claim 1, wherein a voltage regulator (7) and a resistor R105 are connected in parallel between the grid and the source of the pre-charge and discharge switch (5); the anode of the voltage-stabilizing tube (7) is electrically connected with the source electrode of the pre-charging switch (5), and the cathode of the voltage-stabilizing tube (7) is electrically connected with the grid electrode of the pre-charging switch (5).

5. The battery protection circuit according to claim 1, further comprising a capacitor (8) disposed between the source of the first current switching MOS transistor (2) and the source of the second current switching MOS transistor (3).

6. The battery protection circuit according to claim 1, wherein a resistor R58 and a resistor R68 are respectively disposed between the gate of the first current switching MOS transistor (2) and the gate of the second current switching MOS transistor (3) and the controller (6).

7. A battery protection circuit according to claim 4, further comprising a diode (9), wherein the anode of the diode (9) is connected to the controller (6), and the cathode of the diode (9) is connected to the common terminal of the gate of the pre-charge switch (5) and the cathode of the regulator tube (7).