阅读说明：本技术 一种智能反馈电池健康状态的系统和方法 (System and method for intelligently feeding back battery health state ) 是由 周建惠 于 2021-08-13 设计创作，主要内容包括：本发明涉及电动车充电技术领域,提供一种智能反馈电池健康状态的系统,包括充电器、电池,其特征在于,包括充电中转设备,用于监测电池的充电状态；所述充电器连接所述充电中转设备,所述充电中转设备连接所述电池；所述充电中转设备包括MCU控制芯片、温度检测模块、电压检测模块、电流检测模块、DC-DC模块和继电器,所述MCU控制芯片分别连接有温度检测模块、电压检测模块、电流检测模块、DC-DC模块和继电器；所述继电器分别与所述充电器和所述电池连接。本发明提出一种智能反馈电池健康状态的系统和方法,不对电池循环多次进行完全充放电,能够识别电池的健康状态,控制电池的充电,避免电池鼓包。(The invention relates to the technical field of electric vehicle charging, and provides a system for intelligently feeding back the state of health of a battery, which comprises a charger and the battery and is characterized by comprising charging transfer equipment for monitoring the charging state of the battery; the charger is connected with the charging transfer equipment, and the charging transfer equipment is connected with the battery; the charging transfer equipment comprises an MCU control chip, a temperature detection module, a voltage detection module, a current detection module, a DC-DC module and a relay, wherein the MCU control chip is respectively connected with the temperature detection module, the voltage detection module, the current detection module, the DC-DC module and the relay; the relay is connected with the charger and the battery respectively. The invention provides a system and a method for intelligently feeding back the health state of a battery, which do not perform complete charging and discharging on the battery repeatedly, can identify the health state of the battery, control the charging of the battery and avoid the bulge of the battery.)

1. A system for intelligently feeding back the state of health of a battery comprises a charger and the battery, and is characterized by comprising a charging transfer device, a feedback device and a feedback device, wherein the charging transfer device is used for monitoring the charging state of the battery; the charger is connected with the charging transfer equipment, and the charging transfer equipment is connected with the battery;

the charging transfer equipment comprises an MCU control chip, a temperature detection module, a voltage detection module, a current detection module, a DC-DC module and a relay, wherein the MCU control chip is respectively connected with the temperature detection module, the voltage detection module, the current detection module, the DC-DC module and the relay; the relay is connected with the charger and the battery respectively.

The temperature detection module is used for detecting the internal temperature and the external environment temperature of the charging transfer equipment;

the voltage detection module is used for detecting the voltage of the battery;

the current detection module is used for detecting the current when the battery is charged;

the DC-DC module is used for converting the voltage of the battery and providing a power supply for the charging transfer equipment;

the MCU control chip can estimate the health state of the battery according to the data of the battery during charging and control the relay to cut off the charging current.

2. The system according to claim 1, wherein the charging relay device further comprises an NB-IOT module, the NB-IOT module is connected to the MCU control chip, and the DC-DC module is connected to the NB-IOT module through a voltage regulator module.

3. The system for intelligently feeding back the state of health of a battery according to claim 2, wherein the NB-IOT module is wirelessly connected with an operator IOT platform, the operator IOT platform is wirelessly connected with a cloud server, and the cloud server is wirelessly connected with a user-side applet and a production tool respectively.

4. The system according to claim 1, wherein the charging relay device further comprises an LED lamp.

5. A method for intelligently feeding back the state of health of a battery is characterized by comprising the following steps:

1, dividing a charging process of a battery into 3 large stages, wherein the voltages of the large stages are 0-V1, V1-V2 and V2-V3 respectively, and each large stage is divided into a plurality of small stages;

step 2, connecting the charging transfer equipment with the battery, monitoring the initial voltage of the battery by a voltage detection module, judging which charging stage the initial voltage belongs to by an MCU control chip, if the initial voltage belongs to the first stage, entering step 3, and if the initial voltage belongs to the second stage, entering step 5; if the initial voltage belongs to the third stage, entering the step 7;

step 3, connecting the charger with the charging transfer equipment, and starting to perform first-stage charging and calculation of preset allowable charging quantity C1 on the battery;

step 4, when the battery charging time reaches the preset allowable charging quantity C1 of the first stage, judging whether the battery voltage reaches the end point voltage V1 of the first stage, if the battery voltage does not reach the end point voltage V1 of the first stage, judging that the battery has serious faults, and directly entering the step 11, if the battery reaches the end point voltage V1 of the first stage, entering the step 5;

step 5, calculating the constant current charging and the preset allowable charging quantity C2 of the battery at the second stage;

step 6, when the battery charging time reaches the preset allowable charging amount C2 of the second stage, judging whether the battery voltage reaches the end point voltage V2 of the second stage, if the battery voltage does not reach the end point voltage V2 of the second stage, judging that the battery has serious faults, directly entering the step 11, if the end point voltage V2 of the second stage is reached, judging whether the battery is healthy in the charging process of the second stage by the MCU control chip, if so, entering the step 7, and if not, similarly entering the step 7;

step 7, calculating the constant voltage charging and preset allowable charging quantity C3 of the battery in the third stage;

step 8, when the charging time of the battery reaches the preset allowable charging amount C3 of the third stage, the current detection circuit detects the charging current of the battery, the MCU control chip judges whether the battery of the third stage is healthy, if yes, the step 9 is entered, and if not, the step 11 is directly entered;

step 9, charging the battery by pulse voltage until the battery is fully charged;

step 10, ending charging, and feeding back the health condition of the battery to a user;

and 11, controlling a relay to cut off a power supply by the MCU control chip and reminding a user.

6. The method according to claim 5, wherein in the step 4, the MCU control chip further determines the health condition of the battery during the first-stage charging process according to a comparison between a slope of a linear relationship between a rising voltage and time and a slope of a linear relationship between a voltage of a healthy battery and time stored inside the MCU control chip during the first-stage charging of the battery to the constant-amount of electricity C1.

7. The method according to claim 5, wherein in the step 6, the MCU control chip determines the health condition of the battery during the second stage charging process according to a comparison between a slope of a linear relationship between a rising voltage and time and a slope of a linear relationship between a voltage and time of a healthy battery stored inside the MCU control chip during the second stage charging process of the battery to the constant electric quantity C2.

8. The method as claimed in claim 5, wherein in the step 8, the MCU control chip determines the health condition of the battery during the charging process in the third stage according to a comparison between a slope of a linear relationship between a falling current of the battery and time and a slope of a linear relationship between a current of a healthy battery and time stored inside the MCU control chip during the constant voltage charging of the battery into the constant-capacity C3 in the third stage.

9. The method of claim 5, wherein the battery is a lead-acid battery or a lithium battery.

10. The method of claim 9, wherein the lithium battery is a ternary lithium battery, a lithium iron phosphate battery, or a lithium ion polymer battery.

Technical Field

The invention relates to the technical field of electric vehicle charging, in particular to a system and a method for intelligently feeding back the health state of a battery.

Background

It is known that with the development of economy, automobiles in cities are more and more, and the number of automobiles which is increased sharply directly causes abnormal congestion of roads in the cities, so that more and more people select more portable electric vehicles as transportation means. However, the health of the battery of the electric vehicle has not received sufficient attention. The battery thermal runaway can be caused by not controlling the charging process on the premise of unhealthy batteries or battery faults, so that fire disasters are easily caused, and personal safety and social and property safety are seriously threatened.

In addition to the above, when the battery is charged to a constant voltage stage, due to the conditions of too high temperature of the charging environment or water loss of the battery, thermal runaway of the battery causes abnormal reduction of the charging current, further aggravates battery scalding, and causes a rapid rise of the battery temperature, so that the percentage of the capacity cannot completely represent the health state of the battery. The battery capacity detection needs to perform complete charging and discharging on the battery repeatedly, and when an actual user uses the battery, the battery does not have complete charging and discharging conditions, and the battery is damaged due to complete charging and discharging.

Disclosure of Invention

Therefore, in order to solve the above problems, the present invention provides a system and a method for intelligently feeding back a battery health status, which can identify the battery health status, control the charging of the battery, and avoid the battery swelling without performing complete charging and discharging on the battery for multiple cycles.

In order to solve the technical problem, the invention adopts the following scheme: a system for intelligently feeding back the state of health of a battery comprises a charger, the battery, a charging transfer device and a feedback device, wherein the charging transfer device is used for monitoring the charging state of the battery; the charger is connected with the charging transfer equipment, and the charging transfer equipment is connected with the battery;

the charging transfer equipment comprises an MCU control chip, a temperature detection module, a voltage detection module, a current detection module, a DC-DC module and a relay, wherein the MCU control chip is respectively connected with the temperature detection module, the voltage detection module, the current detection module, the DC-DC module and the relay; the relay is connected with the charger and the battery respectively.

The temperature detection module is used for detecting the internal temperature and the external environment temperature of the charging transfer equipment;

the voltage detection module is used for detecting the voltage of the battery;

the current detection module is used for detecting the current when the battery is charged;

the DC-DC module is used for converting the voltage of the battery and providing a power supply for the charging transfer equipment;

the MCU control chip can estimate the health state of the battery according to the data of the battery during charging and control the relay to cut off the charging current.

Further, the charging transfer equipment further comprises an NB-IOT module, the NB-IOT module is connected with the MCU control chip, and the DC-DC module is connected with the NB-IOT module through a voltage stabilizing module.

Further, the NB-IOT module is in wireless connection with an operator IOT platform, the operator IOT platform is in wireless connection with a cloud server, and the cloud server is in wireless connection with a user side applet and a production tool respectively.

Further, the charging transfer equipment further comprises an LED lamp.

The invention also provides a method for intelligently feeding back the health state of the battery, which comprises the following steps:

1, dividing a charging process of a battery into 3 large stages, wherein the voltages of the large stages are 0-V1, V1-V2 and V2-V3 respectively, and each large stage is divided into a plurality of small stages;

step 2, connecting the charging transfer equipment with the battery, monitoring the initial voltage of the battery by a voltage detection module, judging which charging stage the initial voltage belongs to by an MCU control chip, if the initial voltage belongs to the first stage, entering step 3, and if the initial voltage belongs to the second stage, entering step 5; if the initial voltage belongs to the third stage, entering the step 7;

step 3, connecting the charger with the charging transfer equipment, and starting to perform first-stage charging and calculation of preset allowable charging quantity C1 on the battery;

step 4, when the battery charging time reaches the preset allowable charging quantity C1 of the first stage, judging whether the battery voltage reaches the end point voltage V1 of the first stage, if the battery voltage does not reach the end point voltage V1 of the first stage, judging that the battery has serious faults, and directly entering the step 11, if the battery reaches the end point voltage V1 of the first stage, entering the step 5;

step 5, calculating the constant current charging and the preset allowable charging quantity C2 of the battery at the second stage;

step 6, when the battery charging time reaches the preset allowable charging amount C2 of the second stage, judging whether the battery voltage reaches the end point voltage V2 of the second stage, if the battery voltage does not reach the end point voltage V2 of the second stage, judging that the battery has serious faults, directly entering the step 11, if the end point voltage V2 of the second stage is reached, judging whether the battery is healthy in the charging process of the second stage by the MCU control chip, if so, entering the step 7, and if not, similarly entering the step 7;

step 7, calculating the constant voltage charging and preset allowable charging quantity C3 of the battery in the third stage;

step 8, when the charging time of the battery reaches the preset allowable charging amount C3 of the third stage, the current detection circuit detects the charging current of the battery, the MCU control chip judges whether the battery of the third stage is healthy, if yes, the step 9 is entered, and if not, the step 11 is directly entered;

step 9, charging the battery by pulse voltage until the battery is fully charged;

step 10, ending charging, and feeding back the health condition of the battery to a user;

and 11, controlling a relay to cut off a power supply by the MCU control chip and reminding a user.

Further, in the step 4, the MCU control chip may also determine the health condition of the battery during the first-stage charging process according to a comparison between a slope of a linear relationship between a rising voltage and time and a slope of a linear relationship between a voltage of a healthy battery stored in the MCU control chip and time during the first-stage charging of the battery to the quantitative electric quantity C1.

Further, in the step 6, the MCU control chip determines the health condition of the battery during the second stage charging process according to a comparison between a slope of a linear relationship between a rising voltage and time and a slope of a linear relationship between a voltage of a healthy battery stored in the MCU control chip and time during the second stage charging of the battery into the quantitative electric quantity C2.

Further, in the step 8, the MCU control chip determines the health condition of the battery during the third-stage charging process according to a comparison between a slope of a linear relationship between a falling current of the battery and time and a slope of a linear relationship between a current of a healthy battery stored in the MCU control chip and time during the constant-voltage charging of the battery into the quantitative electric quantity C3 in the third stage.

Further, the battery is a lead-acid battery or a lithium battery.

Further, the lithium battery may be a ternary material lithium battery, a lithium iron phosphate battery, or a lithium ion polymer battery.

By adopting the technical scheme, the invention has the beneficial effects that: the invention adopts the charging transfer equipment to detect and feed back the health state of the battery in real time, and charges the battery through the control relay. The invention not only expresses the health condition of the battery by the percentage of the capacity, but also divides the charging process of the battery into 3 stages to judge which charging stage the battery is in according to the initial voltage detected after the charging transfer equipment is connected into the battery, thereby judging various health conditions of the battery according to different conditions of each charging stage and one or more of the charged electric quantity, the terminal voltage, the charging current, the linear relation between the voltage and the time or the linear relation between the current and the time. When the linear relation between voltage and time or the linear relation between current and time is adopted for judgment, the MCU control chip compares the slope of the MCU control chip with the slope of the linear relation between the voltage and the time of the healthy battery stored in the chip or the cloud database or the slope of the linear relation between the current and the time to judge the health degree of the battery, and sends a signal to a user end small program through the NB-IOT module to remind a user of the health problem of the battery so as to prevent the battery from being out of control due to heat and cause potential safety hazards. The invention can set the closing time of the relay, control the charging of the battery, avoid the bulge of the battery and avoid the short circuit ignition caused by over-charging.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention.

Fig. 2 is a flow chart of a method for intelligently feeding back the state of health of a battery according to the invention.

FIG. 3 is a linear voltage versus time graph for the second stage charging process of the present invention.

Fig. 4 is a linear plot of current versus time for the third stage charging process of the present invention.

Detailed Description

The invention will now be further described with reference to the accompanying drawings and detailed description.

Referring to fig. 1, preferably, the present invention takes the following scheme: a system for intelligently feeding back the state of health of a battery comprises a charger and the battery, and comprises a charging transfer device and a feedback device, wherein the charging transfer device is used for monitoring the charging state of the battery; the charger is connected with the charging transfer equipment, and the charging transfer equipment is connected with the battery;

the charging transfer equipment comprises an MCU control chip temperature detection module, a voltage detection module, a current detection module, a DC-DC module and a relay, wherein the MCU control chip is respectively connected with the temperature detection module, the voltage detection module, the current detection module, the DC-DC module and the relay; the relay is connected with the charger and the battery respectively.

The temperature detection module is used for detecting the internal temperature and the external environment temperature of the charging transfer equipment; in this embodiment, the temperature detection module uses the thermistor to perform temperature acquisition and analog-to-digital conversion on the working environment of the charging transfer device.

The voltage detection module is used for detecting the voltage of the battery; in this embodiment, the detection voltage range of the voltage detection module is 0-100V.

The current detection module is used for detecting the current when the battery is charged; in this embodiment, the detection current range of the current detection module is 0 to 10A.

It should be noted that, in this embodiment, the signals output by the temperature detection module, the voltage detection module, and the current detection module are all subjected to analog-to-digital conversion, and digital signals are output and are respectively input to the AD port of the MCU control chip.

The DC-DC module is used for converting the voltage of the battery and providing a power supply for the charging transfer equipment. In this embodiment, the charger provides an input voltage to the battery through the relay to charge the battery. The output voltage of the battery is converted into 5V voltage through the DC-DC module to supply power for the MCU control chip.

The MCU control chip can estimate the health state of the battery according to the data of the battery during charging and control the relay to cut off the charging current.

In the embodiment of the invention, the relay is used for controlling the on-off of the charging current; MCU control chip control relay's break-make can realize the circuit protection to the transfer device that charges as follows specifically:

the MCU control chip judges that the current detected by the current detection module is higher than a value set by a user, and if the set value is y xAh, the relay is switched off to realize overcurrent protection of battery charging; and when the MCU control chip judges that the voltage monitored by the voltage detection module is abnormal and is higher than a voltage value set by a user, the set value is c × dV, and the relay is disconnected, so that the overvoltage protection of battery charging is realized. It should be noted that y is a charge coefficient, which represents the maximum value of the safe charging range, and in practical application, y of the lead-acid battery is 0.2, and the current setting value is 0.2 × xAh; the lithium battery has y equal to 1, and the current set value is 1 × xAh times, wherein x refers to the total capacity of the battery. And c represents the number of batteries in series, and d represents the maximum voltage of a single battery. For example, when y is 0.2, the maximum chargeable current is 0.2 × 12 — 2.4A current of a 48V12AH lead-acid battery of a common electric vehicle; when d is 14.8V and the number of battery strings c of the electric vehicle is 4, the maximum chargeable voltage of the battery is 59.2V.

Further, the charging transfer equipment further comprises an NB-IOT module, the NB-IOT module is connected with the MCU control chip, and the DC-DC module is connected with the NB-IOT module through a voltage stabilizing module. In this embodiment, the 5V voltage output by the DC-DC module is converted into 3.3V voltage by the voltage stabilizing module to supply power to the NB-IOT module. The charging transfer equipment realizes communication with external equipment through the NB-IOT module. It should be noted that the serial port of the NB-IOT module and the serial port of the MCU control chip need to be connected through a level shifter circuit to achieve serial port communication.

Further, the NB-IOT module is in wireless connection with an operator IOT platform, the operator IOT platform is in wireless connection with a cloud server, and the cloud server is in wireless connection with a user side applet and a production tool respectively. The production tool is used for registering equipment to an IOT platform of an operator during production, generating an ID code and an IMEI of the equipment, associating a user card number and storing the user card number to a cloud server. The charging transfer equipment collects current and voltage data of the battery and information such as the health condition of the battery, reports the data to the operator IOT platform through the NB-IOT module, and then the data are pushed to the cloud server and the user side applet through the API of the operator IOT platform, and the instruction of the user side applet is also transmitted to the charging transfer equipment through the operator IOT platform. In order to keep long connection during charging, a port is not aged, the real-time performance of an instruction is improved, a heartbeat packet needs to be sent regularly to keep alive with an IOT (input/output) platform of an operator, and the balance between the heartbeat packet and flow is considered.

Further, the charging transfer equipment further comprises an LED lamp. The LED lamp is used for indicating the working state of the charging transfer equipment. The charging transfer equipment further comprises a buzzer and a key module, wherein the buzzer is used for alarming the abnormal condition of the battery charging. The key module is used for activating NB-IOT module communication.

The invention also provides a method for intelligently feeding back the health state of the battery, which comprises the following steps:

1, dividing a charging process of a battery into 3 large stages, wherein the voltages of the large stages are 0-V1, V1-V2 and V2-V3 respectively, and each large stage is divided into a plurality of small stages;

step 2, connecting the charging transfer equipment with the battery, monitoring the initial voltage of the battery by a voltage detection module, judging which charging stage the initial voltage belongs to by an MCU control chip, if the initial voltage belongs to the first stage, entering step 3, and if the initial voltage belongs to the second stage, entering step 5; if the initial voltage belongs to the third stage, entering the step 7;

step 3, connecting the charger with the charging transfer equipment, and starting to perform first-stage charging and calculation of preset allowable charging quantity C1 on the battery;

step 4, when the charging time of the battery reaches the preset allowable charging quantity C1 of the first stage, judging whether the voltage of the battery reaches the end point voltage of the first stage, if the voltage of the battery does not reach the end point voltage of the first stage, judging that the battery has serious faults, and directly entering step 11, if the voltage of the battery reaches the end point voltage of the first stage, entering step 5;

step 5, calculating the constant current charging and the preset allowable charging quantity C2 of the battery at the second stage;

step 6, when the battery charging time reaches the preset allowable charging quantity C2 of the second stage, judging whether the battery voltage reaches the end point voltage of the second stage, if the battery voltage does not reach the end point voltage of the second stage, judging that the battery has serious faults, directly entering step 11, if the end point voltage of the second stage is reached, judging whether the battery is healthy in the charging process of the second stage by the MCU control chip, if so, entering step 7, and if not, entering step 7;

step 7, calculating the constant voltage charging and preset allowable charging quantity C3 of the battery in the third stage;

step 8, when the charging time of the battery reaches the preset allowable constant voltage charging quantity C3 of the third stage, the current detection circuit detects the current of the battery, the MCU control chip judges whether the battery of the third stage is healthy, if yes, the step 9 is carried out, otherwise, the step 11 is directly carried out;

step 9, charging the battery by pulse voltage until the battery is fully charged;

step 10, ending charging, feeding back the battery health condition to a user, specifically, sending the battery health condition to a user side applet by the MCU control chip through the NB-IOT module;

and 11, controlling a relay to cut off a power supply by the MCU control chip and reminding a user.

Further, in the step 4, the MCU control chip may also determine the health condition of the battery during the first-stage charging process according to a comparison between a slope of a linear relationship between a rising voltage and time and a slope of a linear relationship between a voltage of a healthy battery stored in the MCU control chip and time during the first-stage charging of the battery to the quantitative electric quantity C1.

Further, in the step 6, the MCU control chip determines whether the battery is healthy in the second stage charging process according to a comparison between a slope of a linear relationship between a rising voltage and time and a slope of a linear relationship between a voltage of a healthy battery and time stored in the MCU control chip during the second stage charging of the battery to the quantitative electric quantity C2.

Further, in the step 8, the MCU control chip determines whether the battery is healthy in the third stage charging process according to a comparison between a slope of a linear relationship between a falling current of the battery and time and a slope of a linear relationship between a current of a healthy battery stored in the MCU control chip and time during the constant voltage charging of the battery into the quantitative electric quantity C3 in the third stage.

Specifically, in the embodiment of the present invention, taking a single lead-acid battery with 12V20Ah as an example, the charging stages are divided into three charging stages, namely, voltage 0-V1, voltage V1-V2, and voltage greater than V2-V3, where V1 is 12V, V2 is 14.4V, and V3 is 14.8V:

a first stage charging stage, which is a pre-charging stage, wherein the charging transfer equipment detects that the initial voltage of the battery is less than 12V, the initial voltage of the battery is judged to be in the first stage at the moment, the charging is started after a user connects a charger, the charging transfer equipment performs charging monitoring control in the first stage and performs calculation of preset allowable charging quantity C1, when the voltage reaches 12V when the battery is charged into the charging quantity C1, the battery is judged to be healthy in the charging process in the first stage, and the charging enters a second stage; otherwise, the battery is judged to be in serious fault, the charging is cut off, and the user is reminded. In this example, C1 is 0.1C, and C is the battery rated capacity.

In practical application, in order to more accurately judge the charging condition of the battery in the first stage, the MCU control chip judges the health condition of the battery according to the linear relation between the real-time voltage and the time in the stage, and in order to improve the judging accuracy of the voltage-time relation curve, the charging process in the first stage is divided into a plurality of small stages, in the embodiment, the charging process in the first stage is divided into 100 stages, the MCU control chip respectively compares the slopes of the linear relation between the voltages in different voltage stages and the time with the slopes of the linear relation between the voltages of the healthy battery and the time stored in the MCU control chip, the MCU control chip can more accurately judge whether the relation curve between the voltages in the first stage and the time is abnormal, thereby early warning the abnormal state of the battery and judging whether the battery fault exists, on one hand, judging whether the battery voltage is wrong or not, on the other hand, judging whether the battery is stored too long to cause serious power loss or not, and sends a signal to the user side applet through the NB-IOT module to remind the user.

And in the second stage of charging, the voltage of the battery reaches 12V, the battery is charged by adopting a constant current 3A, and the charging transfer equipment calculates the second stage preset allowable charging quantity C2 of the battery. Where C2 is equal to 1C in this embodiment, and C is the battery rated capacity. When the charging capacity reaches 1C in the stage, if the voltage reaches 14.4v, the MCU control chip carries out further health judgment on the battery through the linear relation between the voltage and the time; if the voltage does not reach 14.4V, the battery is judged to be a high-risk dangerous battery and belongs to a serious fault battery, and the MCU control chip controls the relay to be switched off to stop charging the battery.

When the voltage reaches 14.4v, the following health judgment needs to be performed at the same time, specifically, in the charging process, the voltage detection circuit detects the voltage of the battery at all times to form a linear relation between a rising voltage and time, the MCU control chip judges the health condition of the battery in the second stage charging process according to the comparison between the slope of the linear relation between the rising voltage and the time and the slope of the linear relation between the voltage of the healthy battery stored in the MCU control chip or in the cloud database and the slope of the linear relation between the time and the voltage of the healthy battery, as shown in fig. 3, the rising voltage and the time of the battery in the stage are in a certain linear relation, and the slopes of the linear relation between unhealthy 1 and unhealthy 2 deviate from the slope of the linear relation between healthy battery in a certain range. If the battery is healthy, the battery enters a third-stage charging stage for judgment; otherwise, judging that the battery is unhealthy, and at the moment, judging the current of the battery by adopting constant voltage charging in the next step to judge whether the unhealthy battery needs to be fully restored.

In practical application, in order to improve the judgment accuracy of the voltage-time relation curve, the frequency of the battery voltage can be detected by improving the voltage detection circuit, the second-stage charging process can be divided into a plurality of small stages, in the embodiment, the second-stage charging process is divided into 500 sections, the slopes of the linear relations between the voltages of different voltage sections and the time are respectively compared with the slopes of the linear relations between the voltages of the healthy batteries and the time stored in the MCU control chip, so that the judgment of the MCU control chip is more accurate, the problems are found in time, the health state of the batteries is early warned in advance, and a signal is sent to a user side small program through the NB-IOT module to remind a user.

The MCU control chip judges whether the battery has a fault according to whether the battery can reach the end point voltage V2 of the second stage, and simultaneously judges whether the capacity of the battery at the moment meets the normal requirement according to the relation curve of the voltage and the time.

When the battery voltage does not reach V1 in the first stage or the battery voltage does not reach V2 in the second stage, the MCU control chip judges that the battery has high-risk potential safety hazards and belongs to a battery with serious faults, and sends a signal to a user side small program through the NB-IOT module to remind a user. When the battery voltage reaches the end point voltage V2 in the second stage, but the slope of the linear relation between the voltage and the time deviates from the linear relation between the normal battery voltage and the time by a certain slope, the battery capacity does not reach the normal requirement at the moment, and a signal is sent to the user end small program through the NB-IOT module to remind the user.

And in the third stage of charging, the MCU control chip judges whether the battery has the danger of thermal runaway or not according to the current and the judgment on the current-time relation curve in the increase process of the battery capacity. Specifically, the battery voltage reaches V2(V2 is 14.4V), the battery is charged at a constant voltage by using V3(V3 is 14.8V), the current is detected, and the charge relay device calculates the preset allowable charge amount C3 at the third stage, where C3 is 0.3C and C is the rated capacity of the battery. The charging current decreases as the capacity of the battery increases at this stage. If the battery is charged with 0.3C electricity, if the current is larger than 0.03C, the battery is judged to be unhealthy, if the current is larger than 0.1C, the battery is judged to have serious faults, and the MCU control chip controls the relay to stop continuously charging the battery. If the current is less than or equal to 0.03C, judging that the battery is healthy, and continuously charging the battery for one hour by adopting the gap pulse voltage which is less than 0.03C and stops for 1.36 seconds and 0.64 seconds so as to fully charge the battery and repair and reduce the voltage difference between the batteries connected in series; if the current is greater than 0.03C and less than or equal to 0.1C, the battery is judged to be unhealthy, and the MCU control chip controls the relay to cut off the charging to remind a user. In the charging process of the stage, the MCU control chip compares the slope of the linear relationship between the falling current and the time of the battery in the third stage with the slope of the linear relationship between the current and the time of the healthy battery stored in the MCU control chip at the same time to judge the health condition of the battery in the charging process of the third stage, as shown in fig. 4, the falling current and the time of the battery in the stage are in a certain linear relationship, the slopes of the linear relationships of unhealthy 1 are all smaller than the slopes of the linear relationships of healthy within a certain range, and then the battery is judged to be unhealthy, the MCU control chip controls the relay to cut off the charging, and information is sent to the user side small program to remind the user. The trickle charge, in which the current can be reduced to 0.03C, is one of criteria for the present system to determine that the battery is fully charged.

It should be noted that, in the present invention, the unhealthy battery and the serious failure of the battery are two different concepts, and specifically, the unhealthy battery can be fully charged for continuous use. The serious failure is a safety hazard, for example, the first stage and the second stage do not reach the preset voltage, and the trickle of the third stage is larger than 0.1C.

Also in practical application, in order to improve the judgment accuracy of the current-time relationship curve, the frequency of the battery current can be detected by improving the current detection circuit, the third-stage charging process can be divided into a plurality of sub-stages, in this embodiment, the third-stage charging process is divided into 300 sections, the slopes of the linear relationships between the currents and the times in different sub-stages are respectively compared with the slope of the linear relationship between the currents and the times of the healthy battery stored in the MCU control chip, and the MCU control chip can more accurately judge whether the third-stage current-time relationship curve is abnormal, so as to warn the abnormal state of the battery, judge the battery fault, judge whether the battery has the fire risk, and send a signal to a user-side small program through the NB-IOT module to remind a user.

According to the characteristics of the battery, when the temperature rises, the bearable maximum charging voltage threshold value of the battery can be reduced in the first charging process and the second charging process, when the temperature of the battery is reduced, the bearable maximum charging voltage threshold value is increased, and in the third stage charging process, the temperature of the battery is increased, and the charging current of the battery can not be reduced or can be reduced slowly. Utilize temperature detection circuit to detect the inside temperature and the outside ambient temperature of transfer equipment that charges, the inside temperature or the outside ambient temperature of transfer equipment that charge lead to charging voltage or electric current unusual when charging, and transfer equipment automatically regulated charging voltage and electric current charge, carry out temperature compensation, prevent that the battery from influencing its and charge because ambient temperature reason.

The invention is universal for all electric vehicle batteries and can be lead-acid batteries or lithium batteries. The lithium battery may be a ternary material lithium battery, a lithium iron phosphate battery, or a lithium ion polymer battery. The battery can be a single battery or a plurality of batteries connected in series. For different batteries and the number of strings of batteries, the MCU control chip needs to perform different parameter settings on V1, V2, V3, C1, C2 and C3 according to the voltage and the battery capacity of the batteries.

The user can select the battery model and the charging rate of the user according to the user side applet and send the battery model and the charging rate to the MCU control chip, and the MCU control chip controls the charging transfer equipment to output current, voltage and time suitable for the battery model to charge the battery according to the user selection. The user can monitor the health state of the battery in real time through the user side small program, and can inquire the charging record of the user.

The invention can set the closing time of the relay, when the user sends the total timing time through the small program of the user terminal, the MCU control chip starts the relay to start timing, and detects the voltage, when the voltage reaches a saturation voltage of the battery (calculated according to 14.8V of a single battery in the embodiment), and the total timing set by the user is not reached, the relay is cut off after timing for 3 hours, if the total timing set by the user is short, the battery can not be fully charged, the relay is also cut off when the timing is reached.

The invention adopts the charging transfer equipment to detect and feed back the health state of the battery in real time, and charges the battery through the control relay. The invention not only expresses the health condition of the battery by the percentage of the capacity, but also divides the charging process of the battery into 3 stages to judge which charging stage the battery is in according to the initial voltage detected after the charging transfer equipment is connected into the battery, thereby judging various health conditions of the battery according to different charging conditions and one or more of the charged electric quantity, the terminal voltage, the charging current, the linear relation between the voltage and the time or the linear relation between the current and the time. When the linear relation between voltage and time or the linear relation between current and time is adopted for judgment, the MCU control chip compares the slope of the MCU control chip with the slope of the linear relation between the voltage and the time of the healthy battery stored in the chip or the cloud database or the slope of the linear relation between the current and the time to judge the health degree of the battery, and sends a signal to a user end small program through the NB-IOT module to remind a user of the health problem of the battery so as to prevent the battery from being out of control due to heat and cause potential safety hazards. The invention can set the closing time of the relay, control the charging of the battery, avoid the bulge of the battery and avoid the short circuit ignition caused by over-charging.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.