CN211530813U

CN211530813U - Lithium battery ultra-low power consumption protection device based on battery protection circuit

Info

Publication number: CN211530813U
Application number: CN202020475359.5U
Authority: CN
Inventors: 李训
Original assignee: Shenzhen Fengheyuan Technology Co ltd
Current assignee: Shenzhen Fengheyuan Technology Co ltd
Priority date: 2020-04-02
Filing date: 2020-04-02
Publication date: 2020-09-18
Anticipated expiration: 2030-04-02

Abstract

The utility model discloses an ultra-low power consumption protection device of lithium cell based on battery protection circuit, which comprises a battery, the battery protection chip, a load, the master control treater, the triode, first resistance and second resistance, the anodal input port of power of battery protection chip, power negative pole input port is connected with the anodal and negative pole electricity of battery respectively, the voltage detection port of battery protection chip is connected with the one end electricity of load, the other end of load and the anodal input port of power of battery protection chip, power negative pole input port electricity is connected, the GPIO port of master control treater is connected with the base electricity of triode, the collecting electrode of triode is connected with the anodal electricity of battery, first resistance and second resistance are connected to the electricity in proper order between the anodal of battery and the collecting electrode of triode, the projecting pole electricity of triode is connected to the. The utility model provides a pair of lithium cell ultra-low power consumption protection device based on battery protection circuit can realize longer standby time, extension lithium cell life.

Description

Lithium battery ultra-low power consumption protection device based on battery protection circuit

Technical Field

The utility model relates to a lithium battery protection technology field, concretely relates to lithium cell ultra-low power consumption protection device based on battery protection circuit.

Background

In recent years, more and more products such as PDAs, mobile phones, video cameras, portable music devices, game machines, mopeds, electric vehicles, bluetooth devices, etc. have begun to employ lithium batteries as their main power sources. The reasons are not limited to the advantages of small volume, high energy density, no memory effect, long cycle life, high voltage, low self-discharge rate and the like of the lithium battery. Since lithium batteries are different from nickel-cadmium and nickel-hydrogen batteries, it is necessary to prevent deterioration of characteristics in consideration of safety during charging and discharging. However, protection against overcharge, overdischarge, overcurrent, and short-circuit current of the lithium battery is more important. Therefore, protection circuits are usually designed in the battery pack to protect the lithium battery, and thus the importance of protecting the IC by the lithium battery is seen.

Lithium ion batteries have certain risks in terms of battery safety due to high energy density. Specifically, in the overcharged state, the energy becomes excessive as the battery temperature rises, and the electrolyte decomposes to generate gas, so that the internal pressure of the battery rises, which may cause ignition or rupture. On the other hand, in the over-discharged state, the decomposition of the electrolyte solution leads to deterioration of battery characteristics and durability (i.e., a decrease in the number of charges).

The protection circuit of a lithium ion battery is intended to ensure safety when the battery is in an overcharged and discharged state and to prevent deterioration of characteristics.

A conventional lithium ion battery protection circuit is shown in fig. 1, and its functions include: (1) overcharge protection, (2) overdischarge protection, (3) overcurrent/short circuit protection. The protection operations of these three functions will be described below.

1) And (3) overcharging:

when the lithium battery is overcharged, the electrolyte in the battery is decomposed, so that the temperature rises and gas is generated, so that the pressure rises and the danger of spontaneous combustion or explosion is caused, and the lithium battery protection IC is used for preventing the overcharge.

Overcharge protection IC principle:

when an external charger charges a lithium battery, in order to prevent the internal pressure from rising due to the temperature rise, the charging state needs to be stopped, at this time, the protection IC needs to detect the battery voltage, and when the battery voltage reaches 4.25V (assuming that the battery overcharge point is 4.25V) and the overcharge protection is started, the Power MOS is turned from ON to OFF, and then the charging is stopped.

In addition, overcharge detection may be disturbed by noise to cause malfunction, and a delay time needs to be set so as not to determine noise as overcharge protection.

2) Over-discharge:

in the case of over-discharge, the electrolyte is decomposed to deteriorate the battery characteristics and reduce the number of charges, and the lithium battery protection IC protects the over-discharge of the battery, thereby achieving the protection operation.

Over-discharge protection IC principle:

in order to prevent the over-discharge of the lithium battery, if the lithium battery is connected to the load, when the voltage of the lithium battery is lower than the detection point of the over-discharge voltage (assumed to be set to 2.3V), the over-discharge protection is started, the Power MOS is turned from ON to OFF, and the discharge is cut OFF, so as to achieve the protection to avoid the over-discharge of the battery. And the battery is maintained in a low quiescent current state (standby mode).

When the lithium battery is connected with the charger and the voltage of the lithium battery is higher than the overdischarge voltage, the overdischarge protection function can be released.

In addition, in order to prevent such malfunction, the overdischarge detection is also provided with a delay time for the case of pulse discharge.

3) Overcurrent and short-circuit current:

the discharge is stopped for safety because of the occurrence of over-current or short-circuit current caused by unknown reasons (during discharge or by the wrong touch of the positive and negative electrodes by metal objects).

Current protection IC principle:

when the discharge current is too large or short circuit occurs, the protection IC will start the over (short circuit) current protection, and the over current detection uses Rds (on) of the Power MOS as the sensing impedance to monitor the voltage drop, and stops the discharge if the voltage is higher than the set over current detection voltage.

The formula is as follows:

V-＝I×Rds(on)×2

wherein, V-is the overcurrent detection voltage, and if V-is 0.2V and rds (on) is 25m Ω, the magnitude of the protection current is I4A;

similarly, the overcurrent detection must be provided with a delay time to prevent malfunction that may occur when a sudden current flows.

Normally, after the overcurrent occurs, if the cause of the overcurrent is removed (for example, the overcurrent is immediately separated from the load), the normal state is recovered, and the normal charge and discharge operation can be performed again.

Requirements for protection circuits:

A) high-precision overcharge protection:

when the lithium ion battery has an overcharged state, the charged state must be cut off in order to prevent an increase in internal pressure due to an increase in temperature. The protection IC detects the battery voltage, and when detecting overcharge, sets the Power-MOSFET for detecting overcharge to OFF, and stops charging. At this time, attention should be paid to high accuracy of the detection voltage of overcharge. When the battery is charged, the problem that the battery is fully charged is very attentive to a user, meanwhile, the problem of safety is also considered, and the charging state is cut off when the allowable voltage is reached. To meet these two requirements, a very high precision detector is required, which is 25mV at present, but more precision is required in the future.

B) Reduce the current consumption of the protection IC to achieve the over-discharge protection purpose:

the battery voltage of the charged lithium ion battery is gradually reduced along with the service time, and finally, the battery voltage is reduced to be below a standard value of a specification. At this point, recharging is required. If the battery is continuously used without being charged, the battery may not be recharged (overdischarged state). In order to prevent the over-discharge state, the protection IC detects the state of the battery voltage, and once the state of the battery voltage is below the over-discharge detection voltage, the Power-MOSFET on the discharging side is turned OFF to cut OFF the discharge. However, since the battery itself is naturally discharged and the current consumption of the protection IC is present, it is necessary to minimize the current consumption of the protection IC.

C) Overcurrent/short circuit protection requires low detection voltage and high accuracy:

when a large current is consumed due to a short circuit caused by an unknown cause, the discharge is stopped to ensure safety. In the over-current detection, Rds (on) of Power MOS is used as the sensing impedance to monitor the voltage drop, and the discharge is stopped when the voltage is higher than the over-current detection voltage. In order to effectively apply rds (on) of Power MOS to the charging current and the discharging current, the resistance value needs to be as low as possible (about 20m Ω to 30m Ω at present). Thus, the over-current detection voltage can be low.

D) Realizing a withstand voltage value:

since a high voltage is instantaneously generated when the battery pack is connected to the charger, the protection IC has a "high voltage tolerance requirement" (the protection IC of Ricoh can withstand 28V).

E) Low power consumption:

when protection is reached, its quiescent current consumption must be small (0.1 uA).

F) The zero-voltage charging is as follows:

some batteries may be stored for too long or abnormally, resulting in a voltage as low as 0V, so that the protection IC needs to be charged at 0V.

In summary, the main disadvantages of the prior art are: the quiescent current of traditional lithium battery protection chip all is several uA for standby time just must be done the lithium cell for a long time not enough and charge and discharge, and frequent doing the lithium cell, the life of battery will great shortening.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome prior art not enough, provide a lithium cell ultra-low power consumption protection device based on battery protection circuit, can realize longer standby time, extension lithium cell life.

The technical scheme of the utility model as follows:

a lithium battery ultra-low power consumption protection device based on a battery protection circuit comprises a battery, a battery protection chip, a load, a master control processor, a triode, a first resistor and a second resistor, wherein the battery protection chip is provided with a power supply positive input port, a power supply negative input port and a voltage detection port, the power supply positive input port and the power supply negative input port of the battery protection chip are respectively electrically connected with the positive electrode and the negative electrode of the battery, the voltage detection port of the battery protection chip is electrically connected with one end of the load, the other end of the load is electrically connected with the power supply positive input port and the power supply negative input port of the battery protection chip, a GPIO port of the master control processor is electrically connected with the base electrode of the triode, the collector electrode of the triode is electrically connected with the positive electrode of the battery, and the first resistor and the second resistor are sequentially and electrically connected between the positive electrode of the battery and the collector, the emitter of the triode is electrically connected to the load.

Furthermore, a first capacitor is electrically connected between the positive electrode and the negative electrode of the battery.

Furthermore, a second capacitor is electrically connected among the load, the positive electrode of the battery and the negative electrode of the battery.

Furthermore, a third resistor is electrically connected between the GPIO port of the main control processor and the base electrode of the triode.

Furthermore, a third capacitor is electrically connected between the base electrode and the emitter electrode of the triode.

Furthermore, a fourth resistor is electrically connected between the GPIO port of the main control processor and the emitter of the triode.

Further, the chip model of the battery protection chip is XB6092M2 SV.

Compared with the prior art, the beneficial effects of the utility model reside in that: a lithium cell ultra-low power consumption protection device based on battery protection circuit, utilize the undervoltage of battery protection chip to cross to put protect function and get into the low power consumption mode, when battery voltage is less than 3.0V, the battery protection chip can be in the undervoltage protection mode, get into and equal to cut off the power supply network that the battery supplied power load for the rear end behind this kind of mode to reach the low power consumption mode. When the low-power consumption mode, current consumption can reach and be less than 100nA, and traditional lithium battery protection IC's consumption is the uA grade, consequently compares with traditional product, the utility model discloses obviously there is longer standby time's advantage, has solved the problem to the frequent charge-discharge of lithium cell, still can be accurate under the performance of low-power consumption detect the trigger point of various protections. Just the utility model discloses a structure is simple relatively, and production and use low cost, the range of application is also relatively extensive.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is the utility model provides a pair of lithium battery ultra-low power consumption protection device's circuit schematic based on battery protection circuit.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In order to explain the technical solution of the present invention, the following description is made by using specific examples.

Examples

Referring to fig. 1, the utility model provides a lithium BATTERY ultra-low power consumption protection device based on BATTERY protection circuit, which comprises a BATTERY (BATTERY), a BATTERY protection chip (BATTERY protection IC), a Load (Load), a main control processor (MCU), a triode (Q1), a first resistor (R1) and a second resistor (R2), wherein the BATTERY protection chip (BATTERY protection IC) is provided with a power positive input port (B +/VDD), a power negative input port (B-/VDD), and a voltage detection port (GND/VM), the power positive input port (B +/VDD) and the power negative input port (B-/VDD) of the BATTERY protection IC are respectively electrically connected with the positive electrode and the negative electrode of the BATTERY (BATTERY), the voltage detection port (VM/GND) of the BATTERY protection chip (BATTERY protection IC) is electrically connected with one end of the Load (Load), the other end of the Load (Load) is electrically connected with a power supply positive electrode input port (B +/VDD) and a power supply negative electrode input port (B-/VDD) of the Battery protection chip (Battery protection IC), a GPIO port of the master control processor (MCU) is electrically connected with a base electrode of the triode (Q1), a collector electrode of the triode (Q1) is electrically connected with a positive electrode of the Battery (BATTERY), an anode of the Battery (BATTERY) is electrically connected with a collector electrode of the triode (Q1) in sequence, the first resistor (R1) and the second resistor (R2) are electrically connected, an emitter electrode of the triode (Q1) is electrically connected to the Load (Load), a first capacitor (C1) is electrically connected between the anode and the cathode of the Battery (BATTERY), and a second capacitor (C2) is electrically connected between the Load (Load), the anode of the Battery (BATTERY) and the cathode of the Battery (BATTERY), a third resistor (R3) is electrically connected between a GPIO port of the main control processor (MCU) and the base electrode of the triode (Q1), a third capacitor (C3) is electrically connected between the base electrode and the emitter electrode of the triode (Q1), and a fourth resistor (R4) is electrically connected between the GPIO port of the main control processor (MCU) and the emitter electrode of the triode (Q1).

When in work: the triode (Q1) is controlled to be conducted through a GPIO port of a main control processor (MCU), at the moment, the voltage supplied by a Battery protection chip (Battery protection IC) is divided into half by a first resistor (R1) and a second resistor (R2), and at the moment, the Battery protection chip (Battery protection IC) judges that the working voltage is lower than 3.0V, so that the Battery protection IC immediately enters a low-power protection mode.

The model number of the chip adopted by the Battery protection chip (Battery protection IC) is XB6092M2 SV.

The principle is as follows: the Battery protection chip (Battery protection IC) has the advantages that the undervoltage overdischarge protection function of the Battery protection chip (Battery protection IC) is utilized to enter a low power consumption mode, the Battery protection chip is characterized in that the working voltage range of a lithium Battery is 3.0-4.2V, when the Battery voltage is lower than 3.0V, the Battery protection chip (Battery protection IC) can be in the undervoltage protection mode, and after the Battery protection chip enters the protection mode, a power supply network for a rear-end power supply Load (Load) through a Battery (BATTERY) is cut off, so that the low power consumption mode is achieved. When the low-power consumption mode, current consumption can reach and be less than 100nA, and traditional lithium battery protection IC's consumption is the uA grade, consequently compares with traditional product, the utility model discloses obviously there is longer standby time's advantage, has solved the problem to the frequent charge-discharge of lithium cell, still can be accurate under the performance of low-power consumption detect the trigger point of various protections. Just the utility model discloses a structure is simple relatively, and production and use low cost, the range of application is also relatively extensive.

The above description is only exemplary of the present invention and should not be construed as limiting the present invention, and any modifications, equivalents and improvements made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. The utility model provides an ultra-low power consumption protection device of lithium cell based on battery protection circuit which characterized in that: the battery protection chip is provided with a power supply positive input port, a power supply negative input port and a voltage detection port, the power supply positive input port and the power supply negative input port of the battery protection chip are respectively electrically connected with the positive electrode and the negative electrode of the battery, the voltage detection port of the battery protection chip is electrically connected with one end of the load, the other end of the load is electrically connected with the power supply positive input port and the power supply negative input port of the battery protection chip, the GPIO port of the master control processor is electrically connected with the base electrode of the triode, the collector electrode of the triode is electrically connected with the positive electrode of the battery, and the first resistor and the second resistor are electrically connected between the positive electrode of the battery and the collector electrode of the triode in sequence, the emitter of the triode is electrically connected to the load.

2. The ultra-low power consumption protection device for the lithium battery based on the battery protection circuit as claimed in claim 1, wherein: and a first capacitor is electrically connected between the positive electrode and the negative electrode of the battery.

3. The ultra-low power consumption protection device for the lithium battery based on the battery protection circuit as claimed in claim 1, wherein: and a second capacitor is electrically connected among the load, the positive electrode of the battery and the negative electrode of the battery.

4. The ultra-low power consumption protection device for the lithium battery based on the battery protection circuit as claimed in claim 1, wherein: and a third resistor is electrically connected between the GPIO port of the main control processor and the base electrode of the triode.

5. The ultra-low power consumption protection device for the lithium battery based on the battery protection circuit as claimed in claim 1, wherein: and a third capacitor is electrically connected between the base electrode and the emitter electrode of the triode.

6. The ultra-low power consumption protection device for the lithium battery based on the battery protection circuit as claimed in claim 1, wherein: and a fourth resistor is electrically connected between the GPIO port of the main control processor and the emitter of the triode.

7. The ultra-low power consumption protection device for the lithium battery based on the battery protection circuit as claimed in claim 1, wherein: the battery protection chip adopts a chip model of XB6092M2 SV.