CN109407013B

CN109407013B - Standby battery electric quantity state monitoring circuit and method

Info

Publication number: CN109407013B
Application number: CN201811151248.2A
Authority: CN
Inventors: 韩亮
Original assignee: Guangzhou Xiaopeng Motors Technology Co Ltd
Current assignee: Guangzhou Xiaopeng Motors Technology Co Ltd
Priority date: 2018-09-29
Filing date: 2018-09-29
Publication date: 2020-12-18
Anticipated expiration: 2038-09-29
Also published as: CN109407013A

Abstract

A backup battery state of charge monitoring circuit and method, wherein the circuit includes: the device comprises a standby battery temperature detection unit, a standby battery voltage and current detection unit, a controller and a memory; the standby battery temperature detection unit detects working temperature parameters of the standby battery; the standby battery voltage and current detection unit detects the discharge parameters of the standby battery; the memory is used for storing the performance parameters and the initial monitoring parameters of the backup battery; the controller is connected with the backup battery temperature detection unit, the backup battery voltage and current detection unit and the memory, selectively monitors the electric quantity state of the backup battery based on the detected working temperature parameter of the backup battery, the detected discharge parameter of the backup battery and the stored performance parameter and initial monitoring parameter, and updates the initial monitoring parameter or updates the initial monitoring parameter and the performance parameter. The technical scheme provided by the embodiment of the invention is simple to realize, can flexibly configure curves such as discharge parameters of various types of batteries and the like, and reduces the cost.

Description

Standby battery electric quantity state monitoring circuit and method

Technical Field

The embodiment of the invention belongs to the technical field of battery power management, and particularly relates to a standby battery power state monitoring circuit and a standby battery power state monitoring method.

Background

In 2016, 10 and 01, GB/T32960.2-2016 electric vehicle remote service and management system technical specification part 2 is enforced on new energy vehicles: specifications of in-vehicle terminal (hereinafter, referred to as "specifications"), and "independent operation" regulations in section 4.2.7 of "specifications: the vehicle-mounted terminal can still independently operate after the external power supply is abnormally disconnected, and data uploading to an enterprise platform 10min before the external power supply is disconnected is at least guaranteed. The data refers to the relevant data specified in GB/T32960.3-2016.

In order to meet the product design requirements of the independent operation in the standard, each vehicle-mounted data acquisition manufacturer adds a built-in standby battery to the vehicle-mounted data acquisition product so as to meet the product requirement that the vehicle-mounted terminal can still operate independently after the external power supply is abnormally disconnected and at least ensure that the data 10min before the external power supply is disconnected is uploaded to an enterprise platform in the standard. In order to ensure that the added built-in backup battery can meet the product requirements, the discharge condition of the built-in backup battery needs to be managed, and most of the existing vehicle-mounted terminal manufacturers realize the charge and discharge management of the built-in backup battery by adding a battery power management chip. The scheme for realizing the charging and discharging management of the standby battery by adding the battery power management chip has the following defects:

1. the system is complex to realize: a special battery management chip is needed, and a large number of peripheral separation and digital devices are matched with the special battery management chip to realize the electric quantity management of the built-in standby battery;

2. the system has poor flexibility: the corresponding special battery management chips need to be selected according to the number of the built-in standby batteries, and different special battery management chips need to be selected for matching design according to the number of different built-in standby batteries, so that the design scheme and parameter selection are not flexible enough;

3. the system has high implementation cost: due to the influence of power supply required by the battery management chip and the design of peripheral circuits of the battery management chip, the circuit cost is higher than the cost of an implementation mode using an analog-to-digital converter (ADC) and a software algorithm.

Disclosure of Invention

In order to solve the technical problems of complex system implementation, poor flexibility and high cost existing in the charge and discharge management mode of the built-in backup battery, the embodiment of the invention provides a backup battery electric quantity state monitoring circuit and a backup battery electric quantity state monitoring method.

A battery backup state of charge monitoring circuit comprising: the device comprises a standby battery temperature detection unit, a standby battery voltage and current detection unit, a controller and a memory;

the standby battery temperature detection unit detects working temperature parameters of the standby battery;

the standby battery voltage and current detection unit detects the discharge parameters of the standby battery;

the memory is used for storing the performance parameters and the initial monitoring parameters of the backup battery;

the controller is connected with the backup battery temperature detection unit, the backup battery voltage and current detection unit and the memory, and selectively monitors the electric quantity state of the backup battery based on the detected working temperature parameter of the backup battery, the detected discharge parameter of the backup battery and the stored performance parameter and initial monitoring parameter, and updates the initial monitoring parameter or updates the initial monitoring parameter and the performance parameter.

Further, the performance parameters include discharge voltages at different temperatures and corresponding calibrated battery capacities, and the electric quantity state of the backup battery includes the service life of the backup battery;

the controller determines the current working temperature of the backup battery based on the detected working temperature parameter of the backup battery; determining the current discharge voltage and current discharge current of the backup battery based on the detected discharge parameters of the backup battery; acquiring corresponding calibrated battery capacity from performance parameters stored in a memory based on the determined current working temperature of the backup battery and the determined current discharge voltage of the backup battery; and determining the service time of the backup battery based on the acquired calibrated battery capacity and the determined current discharge current of the backup battery.

Further, the performance parameters also comprise self-discharge parameters of the backup battery at different temperatures, and the controller also comprehensively determines the service life of the backup battery based on the self-discharge parameters of the backup battery;

and/or the presence of a gas in the gas,

the performance parameters further comprise use decay parameters of the backup battery at different temperatures, and the controller further comprehensively determines the use duration of the backup battery based on the use decay parameters of the backup battery.

Furthermore, the backup battery temperature detection unit comprises a thermistor and a thermistor end voltage detection unit, the thermistor is placed close to the backup battery or installed in the backup battery, the thermistor end voltage detection unit detects end voltages of two ends of the thermistor and is connected with a first analog-to-digital conversion interface of the controller, the thermistor end voltage detection unit provides the detected end voltages of the two ends of the thermistor to the controller through the first analog-to-digital conversion interface, and the end voltages of the two ends of the thermistor and the thermal sensitivity of the thermistor serve as working temperature parameters of the backup battery; the controller determines the current operating temperature of the secondary battery based on the acquired terminal voltage across the thermistor and the thermosensitive characteristics of the thermistor.

Further, the thermistor is a positive temperature coefficient thermistor or a negative temperature coefficient thermistor.

Further, the standby battery voltage and current detection unit comprises a series resistor, a series resistor terminal voltage collector and a standby battery terminal voltage collector; the discharge parameters comprise a load value of a load connected in series with the series resistor and voltage values respectively collected by the series resistor terminal voltage collector and the standby battery terminal voltage collector;

the series resistor is connected in series with the standby battery;

the controller determines the current discharge current of the standby battery based on the acquired terminal voltages at the two ends of the series resistor and the resistance value of the series resistor;

the standby battery terminal voltage collector collects the terminal voltages at the two ends of the standby battery and provides the collected terminal voltages at the two ends of the standby battery to a second analog-to-digital conversion interface of the controller; the controller determines the current discharge voltage of the backup battery based on the acquired terminal voltages of the two ends of the backup battery.

Further, when the number of the standby batteries connected in series is increased, the voltage of a second analog-to-digital conversion interface of the controller is adjusted, and the adaptation of a plurality of standby battery series circuits is realized;

when the number of the standby batteries connected in parallel is increased, the resistance value of the series resistor is adjusted, and the adaptation of the parallel circuit of the plurality of standby batteries is realized.

Further, the memory is an internal memory provided in the controller, or the memory includes an external memory and an internal memory provided in the controller.

Further, the negative electrode of the backup battery is grounded,

the standby battery temperature detection unit comprises a negative temperature coefficient thermistor and a thermistor end voltage detection unit;

the negative temperature coefficient thermistor is arranged close to the standby battery, and one end of the negative temperature coefficient thermistor is grounded;

the thermistor end voltage detection unit comprises a thermistor voltage collector, one end of the thermistor voltage collector is connected with the other end of the negative temperature coefficient thermistor, and the other end of the thermistor voltage collector is connected with a first analog-to-digital conversion interface of the controller;

the standby battery voltage and current detection unit comprises a series resistor, a series resistor terminal voltage collector and a standby battery terminal voltage collector;

one end of the series resistor is connected with the anode of the backup battery, the other end of the series resistor is connected with one end of the load, and the other end of the load is grounded;

the standby battery terminal voltage collector comprises a standby battery voltage collector, one end of the standby battery voltage collector is connected with the anode of the standby battery, and the other end of the standby battery voltage collector is connected with the second analog-to-digital conversion interface of the controller;

the series resistor end voltage collector comprises a series resistor voltage collector, one end of the series resistor end voltage collector is connected with the other end of the series resistor, and the other end of the series resistor end voltage collector is connected with a third analog-to-digital conversion interface of the controller;

the controller is connected with a working power supply through a power supply interface and is grounded through a grounding interface;

the memory comprises an internal memory and an external memory, one end of the external memory is connected with a power supply, and the external memory is grounded.

Furthermore, the backup battery temperature detection unit further comprises a divider resistor, one end of the divider resistor is connected with the other end of the negative temperature coefficient thermistor, and the other end of the divider resistor is connected with a working power supply.

A backup battery state of charge monitoring method, comprising:

acquiring performance parameters of a monitored backup battery;

acquiring initial monitoring parameters of a monitored backup battery;

detecting the working parameters of the monitored backup battery, selectively monitoring the electric quantity state of the monitored backup battery based on the acquired performance parameters, the initial monitoring parameters and the detected working parameters, updating the initial monitoring parameters, taking the updated initial monitoring parameters as the acquired initial monitoring parameters, or updating the initial monitoring parameters and the performance parameters, taking the updated initial monitoring parameters as the acquired initial monitoring parameters, and taking the updated performance parameters as the acquired performance parameters.

Further, the performance parameters include discharge voltages at different temperatures and corresponding calibrated battery capacities, the working parameters include monitored working temperature parameters and discharge parameters of the backup battery, and the electric quantity state of the backup battery includes the service life of the backup battery;

monitoring the monitored usage duration of the backup battery includes:

detecting a working temperature parameter of a monitored backup battery, and determining the current working temperature of the backup battery based on the detected working temperature parameter of the backup battery;

detecting a discharge parameter of a monitored backup battery, and determining a current discharge voltage and a current discharge current of the monitored backup battery based on the discharge parameter of the monitored backup battery;

and acquiring corresponding calibration battery capacity from the performance parameters based on the determined current working temperature and current discharge voltage of the monitored backup battery, and determining the service life of the monitored backup battery based on the acquired calibration battery capacity and the determined current discharge current of the monitored backup battery.

Further, the performance parameters further include: the calibration current and the corresponding calibration voltage under a specific load, the capacity retention rate and the placing time length under different temperatures, and the capacity ratio and the recycling times under different temperatures;

the performance parameters are stored in a memory in a form of a table, the table storing the performance parameters is called a first table, and the updating of the performance parameters comprises updating the performance parameters stored in the first table;

the first table is divided into a first sub-table corresponding to the number of initial recycling times of the monitored backup battery smaller than the set threshold value and a second sub-table corresponding to the number of initial recycling times of the monitored backup battery larger than or equal to the set threshold value according to the set threshold value.

Further, the initial monitoring parameters include: the method comprises the following steps of (1) carrying out initial discharge current, initial discharge voltage, initial calibration battery capacity, initial capacity retention rate, initial placement duration, initial capacity ratio and initial cycle use times;

the initial monitoring parameters are stored in a memory in a table form, and the table for storing the initial monitoring parameters is called a second table;

updating the initial monitoring parameters includes updating the initial monitoring parameters stored in the second table.

Further, the monitoring of the state of charge of the monitored backup battery, updating of the initial monitoring parameters or updating of the initial monitoring parameters and the performance parameters includes:

detecting a working temperature parameter of a monitored backup battery, and determining the current working temperature of the monitored backup battery based on the working temperature parameter of the monitored backup battery;

judging whether the current working temperature of the monitored backup battery is within the normal working temperature range of the monitored backup battery;

if the temperature is not in the normal working temperature range, sending an alarm message of abnormal temperature, and stopping operation;

if the temperature is within the normal working temperature range, judging whether the initial recycling times of the monitored backup battery is smaller than a set threshold value; if the initial cycle use times of the monitored backup battery is smaller than a set threshold value, reading corresponding performance parameters in the first sub-table and initial monitoring parameters in the second table, monitoring the electric quantity state of the monitored backup battery according to the current working temperature, the current discharging voltage and the current discharging current determined by the controller, and updating the initial monitoring parameters in the second table; if the number of times of the initial cycle use of the monitored backup battery is larger than or equal to the set threshold, reading corresponding performance parameters in the second sub-table and initial monitoring parameters in the second sub-table, monitoring the electric quantity state of the monitored backup battery according to the current working temperature, the current discharging voltage and the current discharging current determined by the controller, updating the initial monitoring parameters in the second sub-table, matching the parameters in the second sub-table and the second sub-table, judging whether the monitored backup battery is in a normal working state, and judging whether the monitored backup battery has a situation of needing to be warned;

then, checking the service life of the monitored backup battery, and judging whether the monitored backup battery is completely charged and discharged;

if the monitored backup battery is not completely charged and discharged, indicating that the initial cycle use frequency does not need to be updated, returning to the step if the initial cycle use frequency of the monitored backup battery is smaller than the set threshold value, and continuing to execute the operation; and if the monitored backup battery is completely charged and discharged, performing the updating operation of the first table.

Further, the updating operation of the first table includes:

performing 1 addition processing on the initial recycling times, taking the recycling times subjected to the 1 addition processing as new initial recycling times, then judging whether the new initial recycling times are smaller than a set threshold value, and if the new initial recycling times are smaller than the set threshold value, executing the operation of whether the parameters of the first table are updated; if the new initial cycle usage number is larger than or equal to the set threshold, the first sub-table is updated to the second sub-table, parameters in the second table and the second sub-table are compared, whether the monitored backup battery is in a normal working state or not is judged, whether a situation that an alarm is needed exists in the monitored backup battery or not is judged, and then the operation that whether the parameters of the first table are updated or not is executed.

Further, the operation of whether the parameter of the first table is updated includes: judging whether the calibration voltage and the calibration current in the performance parameters stored in the first table need to be updated or not based on the current working temperature, the current discharge voltage and the current discharge current determined by the controller, and if not, executing the operation of whether the number of times of cyclic use in the performance parameters stored in the first table is updated or not; if the performance parameters need to be updated, updating the calibration voltage and the calibration current in the performance parameters stored in the first table by adopting the parameters of the second sub-table, and then executing the operation of judging whether the cycle use times in the performance parameters stored in the first table are updated or not;

the operation of updating the number of times of cycle use in the performance parameters stored in the first table includes: judging whether the number of times of cyclic use in the performance parameters stored in the first table needs to be updated or not based on whether the monitored backup battery is completely charged and discharged or not, and if not, finishing the updating operation of the first table; and if the updating is needed, after the cycle use times in the performance parameters stored in the first table are updated, the updating operation of the first table is finished.

Further, the method is implemented by using the backup battery state of charge monitoring circuit as described in any one of the previous items.

The embodiment of the invention has the following beneficial effects:

1. the circuit and the method for monitoring the electric quantity state of the standby battery are simple to implement, can flexibly configure discharge parameter curves of various types of batteries, and can monitor the charging and discharging processes of the batteries. In some embodiments, the detection of the battery working environment temperature and the charging and discharging parameters can be realized only by using two circuits and matching the negative temperature coefficient thermistor.

2. The circuit and the method for monitoring the electric quantity state of the standby battery provided by the embodiment of the invention avoid the use of a special battery management chip with complexity and high cost to realize the monitoring of the electric quantity state of the battery, and realize low cost.

3. The standby battery electric quantity state monitoring circuit and the standby battery electric quantity state monitoring method are more flexible in implementation method, and the adaptation of a multi-battery series circuit can be realized only by adjusting the voltage of the analog-to-digital conversion interface. In addition, adaptation can be realized by adjusting the resistance value of the series resistor for the parallel battery pack.

4. The circuit and the method for monitoring the electric quantity state of the standby battery provided by the embodiment of the invention have the advantages that the realization error is low, the voltage/current error precision is only +/-2% compared with a special battery management chip, and the estimated service life error of the battery is +/-2%.

Drawings

Fig. 1 is a schematic structural diagram of a backup battery state of charge monitoring circuit according to an embodiment of the present invention;

fig. 2 is a flowchart of a method for monitoring a state of charge of a backup battery according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a preferred embodiment of a backup battery state of charge monitoring circuit according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments and the accompanying drawings. Those skilled in the art will appreciate that the present invention is not limited to the drawings and the following examples. The words "first", "second", and the like are used herein only for distinguishing technical features and do not limit the technical scope. As used herein, the term "include" and its various variants are to be understood as open-ended terms, which mean "including, but not limited to. The term "based on" or "based on" may be understood as "based, at least in part, on" or "based, at least in part, on". The term "one embodiment" may be understood as "at least one embodiment". The term "another embodiment" may be understood as "at least one other embodiment".

According to the embodiment of the invention, through using volt-ampere curves (a volt-ampere curve: a current I is represented by a common ordinate and a voltage U is represented by an abscissa, an I-U image drawn by the curve is called as a volt-ampere characteristic curve of a conductor), a relation between voltage and battery capacity and the like of different batteries under different working temperature conditions as reference bases, and through combining with a multi-channel analog-to-digital Conversion circuit of a controller, monitoring of electric quantity states such as discharge electric quantity calculation, charge and discharge frequency statistics, battery life early warning and the like of a standby battery system in a CDU (Conversion & Distribution Unit) under different working temperature conditions is realized, and the problem that the product function cannot meet relevant specifications due to the fact that the standby battery is scrapped in advance due to the use temperature, excessive charge and discharge and the like of the standby battery system in the use process is avoided.

The CDU refers to a high-voltage 'electronic control' system integration mode integrating functions of a DC/DC converter, a vehicle-mounted charger, a high-voltage junction box and the like. The integration of the CDU system is divided into a two-in-one assembly (including the integration of a DC/DC converter and a vehicle-mounted charger, the integration of the DC/DC converter and a high-voltage junction box or the integration of the vehicle-mounted charger and the high-voltage junction box) and a three-in-one assembly (namely the integration of the DC/DC converter, the vehicle-mounted charger and the high-voltage junction box), and the integration of the CDU system is selected by more and more host factories at home and abroad and is becoming one of the mainstream technologies all over the.

The embodiment of the invention provides a standby battery electric quantity state monitoring circuit, as shown in fig. 1, comprising: a backup battery temperature detection unit, a backup battery voltage current detection unit, a controller and a memory.

The backup battery may be a nickel-hydrogen battery, a lithium battery, a lead-acid battery, or the like.

The standby battery temperature detection unit detects the working temperature parameter of the standby battery.

The backup battery voltage current detection unit detects a discharge parameter of the backup battery.

The memory is used for storing the performance parameters and the initial monitoring parameters of the backup battery.

The performance parameters comprise discharge voltage and corresponding calibrated battery capacity at different temperatures, and the electric quantity state of the backup battery comprises the service life of the backup battery. The controller determines the current working temperature of the backup battery based on the detected working temperature parameter of the backup battery; determining the current discharge voltage and current discharge current of the backup battery based on the detected discharge parameters of the backup battery; acquiring corresponding calibrated battery capacity from performance parameters stored in a memory based on the determined current working temperature of the backup battery and the determined current discharge voltage of the backup battery; and determining the service time of the backup battery based on the acquired calibrated battery capacity and the determined current discharge current of the backup battery.

The operating temperature parameter may include an operating temperature parameter obtained based on a thermistor.

The discharge parameter may include a discharge current parameter or a discharge voltage parameter.

The controller can also store the current discharge voltage and current discharge current of the backup battery in the memory in real time based on the discharge parameters of the backup battery detected by the backup battery voltage and current detection unit.

The state of charge of the backup battery comprises the current battery capacity and the use duration of the backup battery, and can also comprise the cycle number (cycle) of the backup battery. The embodiment of the invention adopts the use duration to represent the time length that the current battery capacity of the backup battery can maintain the communication function of the system, and can judge whether the backup battery meets the design requirement of the product of independent operation in the specification or not based on the use duration. The embodiment of the invention adopts the cycle use times to represent the charge and discharge cycle times of the backup battery, and can judge the service life of the backup battery by means of the cycle use times; the judgment standard of one-time charge and discharge is executed according to the industrial regulations, for example, in the lithium battery industry, when the lithium battery is fully charged and then discharged to less than 10%, the lithium battery is considered to be subjected to the process of one-time full charge and discharge (or called complete charge and discharge), and is counted as 1-time charge and discharge cycle; further, the number of charge and discharge may be appropriately calculated in consideration of the fact that the lithium battery is not fully charged, and may be, for example, written as 0.5 charge and discharge cycles as appropriate.

In addition, the controller can also judge whether the monitored backup battery is completely charged and discharged based on the calibrated battery capacity obtained in the discharging process, judge whether the monitored backup battery is completely charged based on the calibrated battery capacity obtained in the charging process in one charging and discharging cycle, judge whether the monitored backup battery is completely discharged based on the calibrated battery capacity obtained in the discharging process, and if the monitored backup battery is completely charged and discharged, update the cycle use frequency of the backup battery by adding 1. In the embodiment of the invention, the battery capacity fading condition of the backup battery is represented by adopting the cycle number (cycle) of the backup battery and the corresponding capacity ratio (capacity ratio) as the fading parameters. The number of times of the standby battery is recycled and the corresponding parameters such as the capacity ratio can also be stored in the memory in real time.

Furthermore, the controller can update the placing time of the backup battery based on the monitored actual service time of the backup battery. In the embodiment of the invention, the self-discharge condition of the backup battery is represented by using the storage period (storage period) and the corresponding capacity retention rate (capacity retention) of the backup battery as self-discharge parameters. The storage time of the spare battery, the corresponding capacity retention rate and other parameters can also be stored in the memory in real time.

In one embodiment, the controller further comprehensively determines the state of charge (e.g., the usage duration) of the backup battery based on self-discharge parameters of the backup battery at different temperatures and/or usage decay parameters of the backup battery at different temperatures, so that the monitoring dimension of the state of charge of the backup battery is increased, and the monitoring accuracy is improved.

The electric quantity state monitoring circuit of the standby battery can monitor the electric quantity state of the standby battery, and can be used in the charging process of the standby battery and the discharging process of the standby battery.

The monitoring of the state of charge of the backup battery by the backup battery state of charge monitoring circuit may be performed at predetermined time intervals, for example, every 1 hour, or every 12 hours. Or the next monitoring time interval may also be determined based on the current parameter of the backup battery, for example, when the current remaining battery capacity of the backup battery is much larger than the battery capacity of the backup battery for maintaining the system for 10 minutes communication function, the next monitoring time interval may be determined to be a slightly longer time interval, and when the current remaining battery capacity of the backup battery is close to the battery capacity of the backup battery for maintaining the system for 10 minutes communication function, the next monitoring time interval may be determined to be a slightly shorter time interval.

The standby battery electric quantity state monitoring circuit can further judge whether the standby battery needs to be charged or replaced or not based on the acquired electric quantity state of the standby battery.

In an embodiment, a volt-ampere characteristic curve formed by a calibration voltage and a calibration current of the backup battery under a specific load is further added, so that when a system is initialized, a corresponding calibration voltage is obtained according to an initial current, and in a use process of the backup battery based on the specific load, based on the determined current discharge voltage of the backup battery, the corresponding calibration current is found in the volt-ampere characteristic curve by using the determined current discharge voltage as the calibration voltage, based on the found calibration current and the determined current discharge current of the backup battery, a working error of the backup battery is determined, and an electric quantity state of the backup battery is corrected based on the working error.

The embodiment of the present invention further provides a method for monitoring the state of electric power of a backup battery, as shown in fig. 2, including:

acquiring performance parameters of a monitored backup battery;

acquiring initial monitoring parameters of a monitored backup battery;

The performance parameters comprise discharge voltages at different temperatures and corresponding calibrated battery capacities, and the electric quantity state of the standby battery comprises the service life of the standby battery;

monitoring the monitored usage duration of the backup battery includes:

detecting working temperature parameters of the standby battery, and determining the current working temperature of the standby battery based on the detected working temperature parameters of the standby battery;

and acquiring corresponding calibration battery capacity from the performance parameters based on the determined current working temperature and current discharge voltage of the monitored backup battery, and determining the service life of the monitored backup battery based on the acquired calibration battery capacity and the determined current discharge current of the monitored backup battery. For example, the usage time length is the acquired nominal battery capacity ÷ determined current discharge current of the monitored backup battery.

The method of the embodiment of the present invention has the same contents as the foregoing circuit, and is not described herein again.

According to the circuit and the method for monitoring the electric quantity state of the standby battery, disclosed by the embodiment of the invention, the electric quantity state of the battery, even the number of times of recycling, the service life and the like are judged by referring to the strong correlation between the charging and discharging parameters of the battery and the ambient temperature and referring to the calibrated charging and discharging parameter curve parameters of the battery based on the voltage and the current of the battery in the charging and discharging process, so that the electric quantity state of the battery is monitored, the function is simple to realize, the charging and discharging parameter curves of various types of batteries can be flexibly configured, and the cost is; the compatibility is strong, and almost all vehicle batteries (such as lead-acid batteries, nickel-metal hydride batteries, lithium batteries and the like) are compatible.

The following provides an exemplary description of preferred embodiments of a backup battery state of charge monitoring circuit and method according to embodiments of the present invention.

Example 1:

in this embodiment 1, a preferred embodiment of a backup battery temperature detection unit included in a backup battery state of charge monitoring circuit is exemplarily described.

As shown in fig. 3, the backup battery temperature detecting unit includes a thermistor and a thermistor end voltage detecting unit, the thermistor is placed close to or installed inside the backup battery, the thermistor end voltage detecting unit detects end voltages at two ends of the thermistor and is connected with a first analog-to-digital conversion interface (ADC interface) of the controller, the thermistor end voltage detecting unit provides the detected end voltages at two ends of the thermistor to the controller through the first ADC interface, and the detected end voltages at two ends of the thermistor serve as operating temperature parameters of the backup battery; and the controller calculates the working temperature of the standby battery according to the acquired terminal voltage at the two ends of the thermistor and the thermosensitive characteristics of the thermistor.

The thermistor may be a positive temperature coefficient thermistor or a negative temperature coefficient thermistor.

Those skilled in the art will appreciate that in some embodiments, the thermistor may be integrated within the controller, i.e., the controller is a controller capable of providing internal temperature sampling.

Example 2:

in this embodiment 2, a preferred embodiment of a backup battery voltage and current detection unit included in a backup battery state of charge monitoring circuit is exemplarily described. In this embodiment, the discharge parameter includes a discharge voltage parameter, and the battery backup voltage and current detection unit detects a voltage value associated with the battery backup. Of course, the current value associated with the backup battery may also be detected if conditions permit.

As shown in fig. 3, the backup battery voltage current detection unit includes a series resistor, a series resistor terminal voltage collector, and a backup battery terminal voltage collector.

The series resistor is connected in series with the backup battery.

The method comprises the steps that a series resistor terminal voltage collector collects terminal voltages at two ends of a series resistor when a standby battery is charged and discharged, the collected terminal voltages at the two ends of the series resistor are provided for a controller, and the obtained terminal voltages at the two ends of the series resistor are used as discharging parameters of the standby battery; the controller calculates the current discharge current of the backup battery based on the acquired terminal voltage at both ends of the series resistor and the resistance value of the series resistor.

And the standby battery terminal voltage collector collects the terminal voltages at the two ends of the standby battery during charging and discharging of the standby battery, and provides the collected terminal voltages at the two ends of the standby battery as the determined current discharging voltage of the standby battery to a second analog-to-digital conversion interface of the controller.

When the number of the standby batteries connected in series is increased, the terminal voltages at the two ends of the whole standby battery are correspondingly increased, and at the moment, the adaptation of the series circuits of the plurality of standby batteries can be realized only by adjusting the voltage of the second analog-to-digital conversion interface of the controller.

When the number of the standby batteries connected in parallel is increased, the end current of the whole standby battery is correspondingly increased, and at the moment, the adaptation of the parallel circuits of the plurality of standby batteries can be realized only by adjusting the resistance value of the series resistor.

Example 3:

this embodiment 3 exemplifies a preferred embodiment of the memory included in the backup battery state of charge monitoring circuit.

The memory may be an internal memory provided in the controller, and may also include an external memory and an internal memory provided in the controller (see fig. 3). The external memory is connected with the external memory interface of the controller, and the controller can write data into the memory and also can read data from the memory.

Whether the memory further comprises an external memory can be determined according to the storage space of the internal memory and the actual application requirements, and if the storage space of the internal memory can meet the actual application requirements, the external memory is not required.

Example 4:

in this embodiment 4, a preferred embodiment of the backup battery state of charge monitoring circuit is exemplarily described, and reference may be made to fig. 3.

In this embodiment, the discharge parameter includes a discharge voltage parameter, and the battery backup voltage and current detection unit detects a voltage value associated with the battery backup.

In this embodiment, the negative electrode of the backup battery B1 is grounded.

The backup battery temperature detection unit includes a negative temperature coefficient thermistor RT1 and a thermistor terminal voltage detection unit.

The negative temperature coefficient thermistor RT1 is arranged close to the backup battery B1, and one end of the negative temperature coefficient thermistor RT1 is grounded.

Since one end of the ntt 1 is grounded, the voltage detection unit may only include a thermistor voltage collector V3 for collecting the voltage at the other end of the ntt 1. One end of the thermistor voltage collector V3 is connected with the other end of the negative temperature coefficient thermistor RT1, and the other end of the thermistor voltage collector V3 is connected with a first analog-to-digital conversion interface of the controller U1.

In order to prevent the voltage applied by the working power supply V0 on the negative temperature coefficient thermistor RT1 from being too large, the backup battery temperature detection unit further comprises a voltage division resistor R2, one end of the voltage division resistor R2 is connected with the other end of the negative temperature coefficient thermistor RT1, and the other end of the voltage division resistor R2 is connected with the working power supply V0. In this embodiment, thermistor RT1, voltage divider resistor R2, and operating power supply V0 form a temperature detection circuit, and the terminal voltage of negative temperature coefficient thermistor RT1 during charging and discharging of backup battery B1 is [ V0/(RT1+ R2) ]. t 1. Of course, those skilled in the art will appreciate that the thermistor RT1 may be integrated within the controller U1, in which case the voltage divider resistor R2 may be omitted.

The standby battery voltage and current detection unit comprises a series resistor R1, a series resistor terminal voltage collector and a standby battery terminal voltage collector.

One end of the series resistor R1 is connected to the positive electrode of the backup battery B1, the other end of the series resistor R1 is connected to one end of the load, and the other end of the load is grounded. In the present embodiment, the battery B1, the series resistor R1, and the load form a battery discharge circuit.

Because the negative electrode of the backup battery B1 is grounded, the backup battery terminal voltage collector may only comprise a backup battery voltage collector V2, one end of the backup battery voltage collector V2 is connected with the positive electrode of the backup battery B1, and the other end is connected with the second analog-to-digital conversion interface of the controller. In the present embodiment, the voltage collected by the backup battery voltage collector V2 when the backup battery B1 is charged and discharged is the current discharge voltage of the backup battery B1.

Since the voltage of the one end of the series resistor R1 is equal to the voltage collected by the backup battery voltage collector V2, the voltage collector at the end of the series resistor R1 can obtain the voltage at the junction between the one end of the series resistor R1 and the positive electrode of the backup battery B1 by means of the backup battery voltage collector V2, and the voltage collector at the end of the series resistor R1 needs a series resistor voltage collector V1 to obtain the voltage at the other end of the series resistor R1. One end of the series resistor end voltage collector V1 is connected with the other end of the series resistor R1, and the other end of the series resistor end voltage collector V1 is connected with the third analog-to-digital conversion interface of the controller U1. In the embodiment, when the backup battery B1 discharges, the discharge current of the backup battery flows from the one end to the other end of the series resistor R1, and the current discharge current of the backup battery is (V2-V1)/R1; when the backup battery B1 is charged, the charging current of the backup battery flows from the other end to the one end of the series resistor R1, and the current charging current of the backup battery is (V1-V2)/R1.

The internal resistances of the series resistor voltage collector V1, the backup battery voltage collector V2 and the thermistor voltage collector V3 are large, so that the current in the backup battery discharging loop and the temperature detecting loop hardly flows into the controller U1.

The controller is connected with a working power supply V0 through a power supply interface VCC and is grounded through a ground interface GND.

In this embodiment, the memory includes an internal memory and an external memory, one end of the external memory is connected to the power supply V0, and the external memory performs grounding processing. The external memory is communicated with the controller U1 through an external memory interface of the controller U1.

Example 5:

in this embodiment, an exemplary description is given of parameters used for monitoring the state of charge of the backup battery in the backup battery state of charge monitoring circuit and method provided in the embodiments of the present invention.

Because the battery products are chemicals, the electrochemistry of the battery products is strongly related to the temperature, so the discharge parameters of the battery are calibrated according to the actual working temperature of the battery, such as the working range of-20 ℃ to +85 ℃ (for example, the battery capacity of the nickel-hydrogen battery is 100% under the condition of +20 ℃).

And aiming at different heat dissipation conditions, different parameters are set only according to the requirements of the working temperature of the battery. The calibrated parameters can be stored in a fixed storage space of the built-in memory.

And during calibration, actually measuring a charge-discharge parameter characteristic curve formed by the charge-discharge voltage and the battery capacity of the backup battery at different temperatures, and acquiring the charge-discharge voltage and the calibrated battery capacity corresponding to partial nodes on the charge-discharge parameter characteristic curve at each temperature. The corresponding relationship between the temperature, the charge and discharge voltage and the calibrated battery capacity can be recorded in a table form. The first table shows the corresponding calibrated cell capacity values (calibrated cell capacity is in milliampere hours) of the spare cell at-20 ℃, 10 ℃, 0 ℃, 20 ℃ and 85 ℃ and at the charging and discharging voltages of 1400mV, 1300mV, 1250mV, 1200mV, 1100mV and 1000mV, respectively.

TABLE-relationship between temperature, Charge and discharge Voltage and Battery Capacity (example)

As shown in Table I, no current energy was discharged when the voltage of the backup battery was discharged from 1200mV to 1000mV at 85 deg.C, indicating that the backup battery was fully discharged.

When the electric quantity state of the backup battery is monitored, the corresponding calibrated battery capacity can be found according to the current working temperature and the current discharge voltage of the backup battery, and the service life of the backup battery can be obtained based on the found calibrated battery capacity and the current discharge current of the backup battery. For example, the current working temperature of the obtained backup battery is determined to be-20 ℃, the current discharge voltage of the obtained backup battery is determined to be 1100mV, and the current discharge current is 20mA, then according to the temperature of-20 ℃ and the voltage of 1100mV, the corresponding calibrated battery capacity can be found to be 180mAh, and therefore the service life of the obtained backup battery is 9 hours.

Besides monitoring the electric quantity state of the backup battery from the temperature, the voltage and the battery capacity of the backup battery, the dimension of battery self-discharge parameters can be increased to comprehensively monitor the electric quantity state of the backup battery, the residual electric quantity of the backup battery is monitored according to a self-discharge curve, and the monitoring accuracy is improved.

Actually measuring a self-discharge curve consisting of capacity retention rate (capacity retention) and storage period (storage period) of the spare battery at different temperatures, and acquiring the capacity retention rate and the storage period corresponding to partial nodes on the self-discharge curve at each temperature. The relationship between the temperature, the capacity retention rate and the standing time is recorded in the form of a table. Table II shows the storage time (in months) when the spare battery has capacity retention rates of 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30% and 20% at-20 ℃, 45 ℃ and 60 ℃, respectively.

TABLE II relationship between temperature, Capacity Retention and standing time (examples)

When the electric quantity state of the backup battery is monitored, the corresponding battery capacity can be found according to the current working temperature and the charging and discharging voltage of the backup battery, the battery capacity is adjusted according to the capacity retention rate by combining the relationship among the temperature, the placing time and the capacity retention rate in the table II, and the adjusted service time of the backup battery can be obtained according to the adjusted battery capacity and the current discharging current of the backup battery, which is obtained through determination. Therefore, the accuracy of monitoring the electric quantity state of the standby battery can be effectively improved. Similarly, taking the temperature as-20 ℃, the discharge voltage as 1100mV and the discharge current as 20mA as an example, if the spare battery is left for 0.3 month, the capacity retention rate is 90% according to the second table, and the service life of the spare battery after adjustment is 8.1 hours.

In addition, since the battery is a chemical, the stability of the link structure between the corresponding current collector and the active materials of the positive and negative electrodes is reduced along with the change of the density, temperature and active materials of the electrolyte during the charging and discharging processes, so that a loose structure occurs. This will result in an increase in the internal resistance of the battery, which will directly affect the operating voltage, operating current, output energy and power of the battery. Therefore, in this embodiment, the number of battery cycles (cycle) may also be used as an index for measuring the remaining battery capacity, so as to further increase the dimension of monitoring the state of charge of the backup battery.

And measuring a use attenuation curve formed by taking the capacity ratio (capacity ratio) and the cycle number (cycle) of the spare battery at different temperatures as use attenuation parameters, and recording the relationship among the temperature, the capacity ratio and the cycle number in a form of a table. The third table shows the number of times of recycling of the backup battery at 20 ℃ corresponding to 100%, 90%, 80%, 70%, and 60%, respectively.

TABLE III relationship between temperature, Capacity ratio and number of cycles (examples)

When the electric quantity state of the backup battery is monitored, the corresponding battery capacity can be found according to the current working temperature and the discharge voltage of the backup battery, the battery capacity is adjusted twice according to the capacity retention rate and the capacity ratio by combining the relationship among the temperature, the placing time and the capacity retention rate in the second table and combining the relationship among the temperature, the capacity ratio and the cycle use frequency in the third table, and the use time of the backup battery after twice adjustment can be obtained according to the battery capacity after twice adjustment and the current discharge current of the backup battery obtained through determination. Thus, the accuracy of monitoring the electric quantity state of the standby battery can be effectively improved. Similarly, if the temperature is minus 20 ℃, the charge-discharge voltage is 1100mV, and the discharge current is 20mA, and the spare battery is placed for 0.3 month, the capacity retention rate is 90% according to the second table; and if the backup battery has been recycled 900 times, which can be found by a table three (not shown), the capacity ratio at this time is assumed to be 70%, and the service time of the backup battery after two adjustments is 5.67 hours.

Therefore, in the embodiment of the invention, the current working temperature, voltage and current of the backup battery, and the self-discharge parameters and/or the cycle use times can be integrated to determine the electric quantity state of the backup battery. Through the comprehensive consideration of multiple dimensions, the monitoring accuracy of the electric quantity state of the standby battery is improved.

In some embodiments, for convenience of query, the first table, the second table and the third table may be organized into a table, and the table is stored in the internal memory or the external memory.

In addition, a volt-ampere characteristic curve formed by the calibration voltage and the calibration current of the backup battery under a specific load can be added, according to the volt-ampere characteristic curve, not only is a working parameter initialized, but also the performance parameter change condition of the backup battery can be known, and the monitoring result of the electric quantity state of the backup battery can be adaptively corrected, for example, the current discharge voltage of the backup battery is taken as the calibration voltage, the corresponding calibration current is obtained from the volt-ampere characteristic curve, the obtained calibration current is compared with the current discharge current of the backup battery, whether the volt-ampere characteristic curve of the backup battery changes or not can be known, and if the current discharge voltage of the backup battery changes, the electric quantity state (for example, the use duration) of the backup battery can be corrected according to the change rate. For convenience of query, the first table, the second table, the third table and the volt-ampere characteristic curve relation can be organized into a table, and the table is stored in an internal memory or an external memory.

Example 6:

the following describes an exemplary procedure of the backup battery state of charge monitoring method according to an embodiment of the present invention.

The performance parameters comprise calibration current and calibration voltage of the monitored backup battery under a specific load, charge and discharge voltages and corresponding calibration battery capacity at different temperatures, a corresponding relation between capacity retention rate and standing time, and a corresponding relation between capacity ratio and recycling times;

firstly, acquiring performance parameters of a monitored backup battery, wherein the performance parameters comprise:

based on the model or type of the monitored backup battery, acquiring the calibration current and the corresponding calibration voltage of the monitored backup battery under a specific load, the charging and discharging voltages and the corresponding calibration battery capacity under different temperatures;

acquiring the corresponding relation between the capacity retention rate of the monitored backup battery and the standing time; and the corresponding relation between the capacity ratio and the number of times of recycling;

the performance parameters may be stored in the memory in the form of a table, the table storing the performance parameters being referred to as a first table, and updating the performance parameters includes updating the performance parameters stored in the first table. In one embodiment, the first table is divided into a first sub-table corresponding to the number of initial recycling times of the monitored backup battery being less than the set threshold and a second sub-table corresponding to the number of initial recycling times of the monitored backup battery being greater than or equal to the set threshold according to the set threshold; the parameters stored in the first sub-table and the parameters stored in the second sub-table may be the same or different.

Secondly, obtain the initial monitoring parameter of backup battery monitored, include:

estimating initial discharge current of the monitored backup battery based on the model or type of the monitored backup battery; taking the initial discharge current as a calibration current, and acquiring a calibration voltage corresponding to the calibration current as an initial discharge voltage; acquiring initial calibration battery capacity corresponding to the initial discharge voltage based on the initial discharge voltage;

acquiring an initial capacity retention rate and an initial placing time of a monitored backup battery, an initial capacity ratio and initial recycling times;

the initial monitoring parameters may also be stored in the memory in the form of a table, the table storing the initial monitoring parameters is referred to as a second table, and the updating the initial monitoring parameters includes updating the initial monitoring parameters stored in the second table.

Then, the monitoring of the state of charge of the monitored backup battery, the updating of the initial monitoring parameters or the updating of the initial monitoring parameters and the performance parameters includes:

judging whether the current working temperature of the monitored backup battery is within the normal working temperature range of the monitored backup battery, for example, whether the current working temperature of the monitored backup battery is within the temperature range of 20-65 ℃;

and if the temperature is not in the normal working temperature range, sending out a warning message of abnormal temperature, and stopping operation.

If the temperature is within the normal working temperature range, judging whether the initial cycle use frequency of the monitored backup battery is smaller than a set threshold value, for example, the set threshold value is 900 times; if the initial cycle use times of the monitored backup battery is smaller than a set threshold value, reading corresponding performance parameters in the first sub-table and initial monitoring parameters in the second table, monitoring the electric quantity state of the monitored backup battery according to the current working temperature, the current discharging voltage and the current discharging current determined by the controller, and updating the initial monitoring parameters in the second table; if the number of times of the initial cycle use of the monitored backup battery is larger than or equal to the set threshold, reading corresponding performance parameters in the second sub-table and initial monitoring parameters in the second sub-table, monitoring the electric quantity state of the monitored backup battery according to the current working temperature, the current discharging voltage and the current discharging current determined by the controller, updating the initial monitoring parameters in the second sub-table, matching the parameters in the second sub-table and the second sub-table, judging whether the monitored backup battery is in a normal working state, and judging whether the monitored backup battery has a situation (such as service life alarm) needing to be alarmed;

if the monitored backup battery is not completely charged and discharged, indicating that the initial cycle use frequency does not need to be updated, returning to the operation that if the initial cycle use frequency of the monitored backup battery is smaller than the set threshold value, and continuing to execute the operation;

and if the charging and discharging are completed and the number of times of the initial cycle use needs to be updated, executing the updating operation of the first table.

The update operation of the first table comprises: performing 1 addition processing on the initial recycling times, taking the recycling times subjected to the 1 addition processing as new initial recycling times, then judging whether the new initial recycling times are smaller than a set threshold value, and if the new initial recycling times are smaller than the set threshold value, executing the operation of whether the parameters of the first table are updated; if the new initial cycle usage number is larger than or equal to the set threshold, the first sub-table is updated to the second sub-table, parameters in the second table and the second sub-table are compared, whether the monitored backup battery is in a normal working state or not is judged, whether a situation (such as service life alarm) needing alarm exists in the monitored backup battery or not is judged, and then whether the parameters of the first table are updated or not is executed.

The operation of whether the parameter of the first table is updated comprises the following steps: judging whether the calibration voltage and the calibration current in the performance parameters stored in the first table need to be updated or not based on the current working temperature, the current discharge voltage and the current discharge current determined by the controller, and if not, executing the operation of whether the number of times of cyclic use in the performance parameters stored in the first table is updated or not; and if the updating is needed, updating the calibration voltage and the calibration current in the performance parameters stored in the first table by using the parameters of the second sub-table, and then executing the operation of judging whether the cyclic use times in the performance parameters stored in the first table are updated or not.

Wherein monitoring the monitored service life of the backup battery comprises:

and determining the service duration of the monitored backup battery based on the obtained calibrated battery capacity, the initial capacity retention rate and the initial capacity ratio obtained from the second table and the determined current discharge current of the monitored backup battery, for example, the initial capacity retention rate obtained when the service duration is equal to the obtained calibrated battery capacity, the initial capacity ratio and the initial capacity ratio divided by the determined current discharge current of the monitored backup battery.

For another example, based on the obtained calibrated battery capacity, the initial capacity retention rate and the initial capacity ratio of the monitored backup battery and the determined current discharge current, the service life of the monitored backup battery is determined, and whether the monitored backup battery needs to be charged is determined according to the service life so as to avoid the situation that the monitored backup battery is over-discharged. For another example, whether the monitored backup battery is completely charged and discharged is judged based on the acquired calibrated battery capacity of the monitored backup battery, if the monitored backup battery is completely charged and discharged, the number of initial recycling times of the monitored backup battery is added by 1 to be used as a new number of initial recycling times, the number of initial recycling times stored in the memory is updated, and the initial capacity ratio is updated correspondingly. For another example, the initial placement period and the initial capacity ratio are updated according to the monitored actual usage period of the backup battery. For another example, the service life of the monitored backup battery is determined according to the acquired number of times of recycling of the monitored backup battery, so as to determine whether the monitored backup battery needs to be replaced, for example, if the number of times of recycling exceeds the rated service life of the monitored backup battery, the monitored backup battery needs to be replaced. For another example, it is determined whether the charging operation of the monitored backup battery needs to be stopped according to the acquired calibrated battery capacity of the monitored backup battery, so as to avoid the situation that the monitored backup battery is overcharged.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A backup battery state of charge monitoring circuit, comprising: the device comprises a standby battery temperature detection unit, a standby battery voltage and current detection unit, a controller and a memory;

the controller is connected with the backup battery temperature detection unit, the backup battery voltage and current detection unit and the memory, and selectively monitors the electric quantity state of the backup battery based on the detected working temperature parameter of the backup battery, the detected discharge parameter of the backup battery and the stored performance parameter and initial monitoring parameter, and updates the initial monitoring parameter or updates the initial monitoring parameter and the performance parameter;

the controller monitoring the service life of the backup battery comprises:

detecting discharge parameters of the backup battery, and determining the current discharge voltage and current discharge current of the backup battery based on the detected discharge parameters of the backup battery;

acquiring corresponding calibrated battery capacity from performance parameters based on the determined current working temperature and current discharge voltage of the backup battery, and determining the service life of the backup battery based on the acquired calibrated battery capacity and the determined current discharge current of the backup battery;

the performance parameters further include: the calibration current and the corresponding calibration voltage under a specific load, the capacity retention rate and the placing time length under different temperatures, and the capacity ratio and the recycling times under different temperatures;

the first table is divided into a first sub-table and a second sub-table according to a set threshold, wherein the initial recycling times corresponding to the standby battery are smaller than the set threshold, and the initial recycling times corresponding to the standby battery are larger than or equal to the set threshold;

the initial monitoring parameters include: the method comprises the following steps of (1) carrying out initial discharge current, initial discharge voltage, initial calibration battery capacity, initial capacity retention rate, initial placement duration, initial capacity ratio and initial cycle use times;

the controller updating the initial monitoring parameters includes updating the initial monitoring parameters stored in the second table;

the controller monitors the electric quantity state of the backup battery, updates the initial monitoring parameters or updates the initial monitoring parameters and the performance parameters, and comprises the following steps:

detecting working temperature parameters of a standby battery, and determining the current working temperature of the standby battery based on the working temperature parameters of the standby battery;

judging whether the current working temperature of the standby battery is within the normal working temperature range of the standby battery;

if the temperature is within the normal working temperature range, judging whether the initial cycle use frequency of the backup battery is less than a set threshold value; if the initial cycle use times of the standby battery is smaller than the set threshold, reading corresponding performance parameters in the first sub-table and initial monitoring parameters in the second table, monitoring the electric quantity state of the standby battery according to the current working temperature, the current discharging voltage and the current discharging current determined by the controller, and updating the initial monitoring parameters in the second table; if the initial cycle use frequency of the standby battery is larger than or equal to the set threshold value, reading corresponding performance parameters in the second sub-table and initial monitoring parameters in the second sub-table, monitoring the electric quantity state of the standby battery according to the current working temperature, the current discharging voltage and the current discharging current determined by the controller, updating the initial monitoring parameters in the second sub-table, matching the parameters in the second sub-table and the second sub-table, judging whether the standby battery is in a normal working state, and judging whether the standby battery has a condition needing to be warned;

then, checking the service life of the backup battery, and judging whether the backup battery is completely charged and discharged;

if the backup battery is not completely charged and discharged, indicating that the initial cycle use times do not need to be updated, returning to the step if the initial cycle use times of the backup battery are smaller than the set threshold value, and continuing to execute the operation; if the backup battery is fully charged and discharged, the update operation of the first table is performed.

2. The battery state of charge monitoring circuit of claim 1, wherein the operation of updating the first table comprises:

performing 1 addition processing on the initial recycling times, taking the recycling times subjected to the 1 addition processing as new initial recycling times, then judging whether the new initial recycling times are smaller than a set threshold value, and if the new initial recycling times are smaller than the set threshold value, executing the operation of whether the parameters of the first table are updated; if the new initial cycle use times is larger than or equal to the set threshold, the first sub-table is updated to the second sub-table, parameters in the second table and the second sub-table are compared, whether the standby battery is in a normal working state or not is judged, whether a situation that an alarm is needed exists in the standby battery or not is judged, and then the operation that whether the parameters of the first table are updated or not is executed.

3. The battery state of charge monitoring circuit of claim 1, wherein the performance parameters further include self-discharge parameters of the battery backup at different temperatures, and the controller further determines the usage duration of the battery backup based additionally on the self-discharge parameters of the battery backup;

and/or the presence of a gas in the gas,

4. The backup battery state of charge monitoring circuit of any one of claims 1 to 3, wherein the backup battery temperature detection unit comprises a thermistor and a thermistor terminal voltage detection unit, the thermistor is placed close to the backup battery or installed inside the backup battery, the thermistor terminal voltage detection unit detects the terminal voltage across the thermistor and is connected with the first analog-to-digital conversion interface of the controller, the thermistor terminal voltage detection unit provides the detected terminal voltage across the thermistor to the controller through the first analog-to-digital conversion interface, the terminal voltage across the thermistor and the thermosensitive characteristic of the thermistor serve as the operating temperature parameter of the backup battery; the controller determines the current operating temperature of the secondary battery based on the acquired terminal voltage across the thermistor and the thermosensitive characteristics of the thermistor.

5. The backup battery state of charge monitoring circuit of claim 4, wherein the thermistor is a positive temperature coefficient thermistor or a negative temperature coefficient thermistor.

6. The backup battery state of charge monitoring circuit of any one of claims 1 to 3, wherein the backup battery voltage current detection unit comprises a series resistor, a series resistor terminal voltage collector and a backup battery terminal voltage collector; the discharge parameters comprise a load value of a load connected in series with the series resistor and voltage values respectively collected by the series resistor terminal voltage collector and the standby battery terminal voltage collector;

the series resistor is connected in series with the standby battery;

7. The battery state of charge monitoring circuit of claim 6, wherein when the number of the backup batteries connected in series is increased, the voltage of the second analog-to-digital conversion interface of the controller is adjusted to realize the adaptation of the plurality of backup battery series circuits;

8. The backup battery state of charge monitoring circuit of any of claims 1 through 3, wherein said memory is an internal memory provided in the controller, or said memory comprises an external memory and an internal memory provided in the controller.

9. The battery state of charge monitoring circuit of any of claims 1-3, wherein the negative pole of the battery backup is connected to ground,

10. The battery state of charge monitoring circuit of claim 9, wherein the backup battery temperature detection unit further comprises a voltage divider resistor, one end of the voltage divider resistor is connected to the other end of the ntc thermistor, and the other end of the voltage divider resistor is connected to the operating power supply.

11. A method for monitoring the state of charge of a backup battery is characterized by comprising the following steps:

acquiring performance parameters of a monitored backup battery;

acquiring initial monitoring parameters of a monitored backup battery;

detecting working parameters of the monitored backup battery, selectively monitoring the electric quantity state of the monitored backup battery on the basis of the acquired performance parameters, the initial monitoring parameters and the detected working parameters, and updating the initial monitoring parameters, wherein the updated initial monitoring parameters are used as the acquired initial monitoring parameters, or updating the initial monitoring parameters and the performance parameters, the updated initial monitoring parameters are used as the acquired initial monitoring parameters, and the updated performance parameters are used as the acquired performance parameters;

the performance parameters comprise discharge voltages at different temperatures and corresponding calibrated battery capacities, the working parameters comprise working temperature parameters and discharge parameters of the monitored backup battery, and the electric quantity state of the monitored backup battery comprises the service life of the monitored backup battery;

monitoring the monitored usage duration of the backup battery includes:

acquiring corresponding calibration battery capacity from performance parameters based on the determined current working temperature and current discharge voltage of the monitored backup battery, and determining the service life of the monitored backup battery based on the acquired calibration battery capacity and the determined current discharge current of the monitored backup battery;

the first table is divided into a first sub-table and a second sub-table according to a set threshold, wherein the initial recycling times of the monitored backup battery are smaller than the set threshold, and the initial recycling times of the monitored backup battery are larger than or equal to the set threshold;

updating the initial monitoring parameters comprises updating the initial monitoring parameters stored in the second table;

monitoring the electric quantity state of the monitored backup battery, updating initial monitoring parameters or updating initial monitoring parameters and performance parameters, and comprising the following steps:

if the temperature is within the normal working temperature range, judging whether the initial recycling times of the monitored backup battery is smaller than a set threshold value; if the initial cycle use times of the monitored backup battery is smaller than a set threshold value, reading corresponding performance parameters in the first sub-table and initial monitoring parameters in the second table, monitoring the electric quantity state of the monitored backup battery according to the current working temperature, the current discharging voltage and the current discharging current determined by the controller, and updating the initial monitoring parameters in the second table; if the initial cycle use times of the monitored backup battery is larger than or equal to the set threshold, reading corresponding performance parameters in a second sub-table and initial monitoring parameters in the second sub-table, monitoring the electric quantity state of the monitored backup battery according to the current working temperature, the current discharging voltage and the current discharging current determined by the controller, updating the initial monitoring parameters in the second sub-table, matching the parameters in the second sub-table and the second sub-table, judging whether the monitored backup battery is in a normal working state, and judging whether the monitored backup battery has a situation of needing warning;

12. The method of claim 11, wherein the performance parameters further include self-discharge parameters of the monitored battery backup at different temperatures, and wherein the controller additionally determines a duration of use of the monitored battery backup based on the self-discharge parameters of the monitored battery backup;

and/or the presence of a gas in the gas,

the performance parameters further include usage decay parameters of the monitored backup battery at different temperatures, and the controller further synthetically determines a usage duration of the monitored backup battery based additionally on the usage decay parameters of the monitored backup battery.

13. The method of claim 11, wherein the operation of updating the first table comprises:

14. The method of claim 13, wherein the operation of whether the parameter of the first table is updated comprises: judging whether the calibration voltage and the calibration current in the performance parameters stored in the first table need to be updated or not based on the current working temperature, the current discharge voltage and the current discharge current determined by the controller, and if not, executing the operation of whether the number of times of cyclic use in the performance parameters stored in the first table is updated or not; if the performance parameters need to be updated, updating the calibration voltage and the calibration current in the performance parameters stored in the first table by adopting the parameters of the second sub-table, and then executing the operation of judging whether the cycle use times in the performance parameters stored in the first table are updated or not;

15. The method according to any one of claims 11 to 14, wherein the method is implemented using a battery backup state of charge monitoring circuit according to any one of claims 1 to 10.