CN111337840A - Capacity measuring method in charging process - Google Patents
Capacity measuring method in charging process Download PDFInfo
- Publication number
- CN111337840A CN111337840A CN202010421031.XA CN202010421031A CN111337840A CN 111337840 A CN111337840 A CN 111337840A CN 202010421031 A CN202010421031 A CN 202010421031A CN 111337840 A CN111337840 A CN 111337840A
- Authority
- CN
- China
- Prior art keywords
- charging
- value
- mcu
- voltage
- current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/382—Arrangements for monitoring battery or accumulator variables, e.g. SoC
- G01R31/3842—Arrangements for monitoring battery or accumulator variables, e.g. SoC combining voltage and current measurements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/382—Arrangements for monitoring battery or accumulator variables, e.g. SoC
- G01R31/3828—Arrangements for monitoring battery or accumulator variables, e.g. SoC using current integration
Abstract
The invention relates to a capacity measuring method in a charging process, which comprises the following steps of 1) initializing a charger and setting a matching voltage and a constant voltage current value; 2) visualization of the step 1 operation; 3) detecting the state of a charged lithium battery or a lithium battery pack; 4) inputting a starting instruction; 5) multiplying the charging current value according to a certain time period, and adding the multiplied value; 6) displaying information in turn, and storing the added product value; 7) when the charging current value becomes 0, the final addition integrated value is displayed, and the value, namely the charging amount, is shown.
Description
Technical Field
The invention relates to a charging method for measuring electric quantity, in particular to a capacity measuring method in a charging process.
Background
The lithium battery provides an energy storage scheme with higher capacity for electronic products, so that equipment such as mobile phones and digital cameras can run for a long time in a high-performance state, abundant reserve energy is provided for large-scale equipment such as new energy automobiles, the requirements of daily life can be met, and the life of people is greatly facilitated.
However, since these lithium batteries are chemical energy batteries in nature, as the service time goes by, the battery capacity will be attenuated compared with the factory state, however, the user cannot know detailed and specific battery capacity state information in each charging process, and only can give a more accurate value to the battery detection device for charge and discharge tests.
However, this approach has several significant disadvantages: firstly, the time is long, the battery is always emptied of electric quantity after the capacity value is obtained through discharging, and recharging is needed, so that the operation is very complicated; secondly, although the measuring method at the present stage is based on constant current and carries out simple counting and accumulation values, the whole-process constant current cannot be realized at all under the actual condition, so that errors can occur in the real calculating process; third, most of the schemes for measuring the voltage and current value variables in a short time are calculated according to functions of empirical values, however, the uncertainty factor of the actual battery condition is large, and the capacitance value calculated by the empirical value function has a large error.
Disclosure of Invention
Aiming at the technical defects in the background art, the invention provides a capacity measuring method in a charging process, which precisely measures the charging amount according to the normal charging process, solves the technical problems and meets the actual requirements, and the specific technical scheme is as follows:
a method of capacity measurement for a charging process, comprising the steps of:
step 2, the charging voltage value is transmitted to an MCU arranged in the charger, the charging voltage value is processed by the MCU and then output as a display signal, the display signal is displayed by a display screen, and the step 3 is carried out;
step 3, the charged battery or the battery pack is connected to the charger with correct polarity, the MCU judges the voltage and the polarity of the charged battery or the battery pack, if the polarity is wrong, the MCU alarms and stops charging, if the voltage is too low, the MCU alarms and stops charging, and the MCU enters step 4;
step 4, the MCU enters a state of waiting for a charging instruction until a signal instruction for starting charging is input, and then the MCU enters step 5;
step 5, starting the charging process, converting the acquired analog signal of the charging current into a digital quantity by the MCU, carrying out sampling and digital filtering on the digital quantity every 0.5 second/time, carrying out milliampere-hour multiplication operation of 0.5 second/time to obtain a product value, carrying out addition integration (namely a Fourier-grade integral method) on the product value obtained each time to obtain an addition integration value, and entering step 6;
step 6, the MCU displays the real-time voltage value, the charging current value and the addition integrated value in turn in the charging process according to the sequence, stores the real-time voltage value, the charging current value and the addition integrated value in the MCU, and enters step 7;
and 7, when the charging current value of the charged battery or the battery pack becomes 0, ending the charging process, outputting the finally obtained addition integrated value as a display digital value by the MCU, and displaying the display digital value by the display screen, wherein the display value is the size of the charging quantity.
As a further technical scheme of the invention, the charger further comprises an AC/DC converter, a constant voltage and constant current module, a charging loop, a voltage regulation module, a current and voltage sampling module and an input key.
As a further technical scheme of the invention, an ADC digital-to-analog converter, a digital filter and a calculator are arranged in the MCU.
As a further technical scheme of the invention, the input key comprises a START signal and a RESET signal.
As a further technical solution of the present invention, the unit of the product value and the addition value in the steps 5 and 6 is milliampere hour or ampere hour.
As a further technical solution of the present invention, the unit of the addition integrated value finally obtained in the step 7 is ampere hour.
As a further technical solution of the present invention, the formula of the milliamp-hour multiplication is that the measured current value × unit time value = milliamp-hour value or amp-hour value in the unit time.
The invention has the beneficial effects that:
1. regardless of the state of the lithium battery or the lithium battery pack to be measured, the charging process is the process of measuring the capacity, and when the final measurement result is obtained, the charging is also finished, so that the lithium battery or the lithium battery pack can be used immediately, and the time is saved;
2. the charging value is directly calculated according to the real-time voltage and current value regardless of the influence caused by the constant voltage and the constant current state, and the real measured value is directly obtained by integrating the charging value, but not the calculated value of the average number, so that the calculation mode is simplified;
3. the charging device is not influenced by the charging environment, so that the charging device can be obtained, a user can conveniently know the real charging amount, the charging amount can be regarded as the capacitance, and the charging device is simple to operate and very practical.
Drawings
FIG. 1 is a block diagram of the system architecture of the present invention.
FIG. 2 is a circuit diagram of the main loop circuit of the present invention.
FIG. 3 is a schematic diagram of the MCU control and display screen portion of the present invention.
Detailed Description
Embodiments of the present invention will be described below with reference to the accompanying drawings and related embodiments, wherein the following related embodiments are merely preferred embodiments for better illustrating the present invention itself, and the embodiments of the present invention are not limited to the following embodiments, and the present invention relates to the related essential parts in the technical field, which should be regarded as the known technology in the technical field and can be known and grasped by those skilled in the art.
A method of capacity measurement for a charging process, comprising the steps of:
step 2, the charging voltage value is transmitted to an MCU arranged in the charger, the charging voltage value is processed by the MCU and then output as a display signal, the display signal is displayed by a display screen, and the step 3 is carried out;
step 3, the charged battery or the battery pack is connected to the charger with correct polarity, the MCU judges the voltage and the polarity of the charged battery or the battery pack, if the polarity is wrong, the MCU alarms and stops charging, if the voltage is too low, the MCU alarms and stops charging, and the MCU enters step 4;
step 4, the MCU enters a state of waiting for a charging instruction until a signal instruction for starting charging is input, and then the MCU enters step 5;
step 5, starting the charging process, converting the acquired analog signal of the charging current into a digital quantity by the MCU, carrying out sampling and digital filtering on the digital quantity every 0.5 second/time, carrying out milliampere-hour multiplication for 0.5 second/time to obtain a product value, carrying out addition integration on the product value obtained each time to obtain an addition integration value, namely carrying out Fourier series calculation, and entering step 6;
step 6, the MCU displays the real-time voltage value, the charging current value and the addition integrated value in turn in the charging process according to the sequence, stores the real-time voltage value, the charging current value and the addition integrated value in the MCU, and enters step 7;
and 7, when the charging current value of the charged battery or the battery pack becomes 0, ending the charging process, outputting the finally obtained addition integrated value as a display digital value by the MCU, and displaying the display digital value by the display screen, wherein the display value is the size of the charging quantity.
The circuit principle involved in the logic algorithm of the above steps is further detailed as understood from fig. 1, and as seen in conjunction with fig. 2 and 3.
First, a main circuit, i.e., a main circuit portion, will be described.
The circuit mainly realizes 5 functions of constant voltage, constant current, current sampling, sampling signal linear amplification and charging control.
A constant voltage control module (DC/DC module) which is composed of an Integrated Chip (IC) controlled by PWM and a triode, a capacitor, an inductor and a resistor is used for reducing the voltage of input direct current 15V through PWM pulse width modulation, and stable 4.2V (common charging end voltage), 5V or other corresponding charging voltage values are obtained on an output capacitor. 2 resistors of the DC/DC module form a constant voltage detection feedback sample and send the constant voltage detection feedback sample to the PWM control IC, the output of the voltage value of the DC/DC module is realized through the resistance value setting of the 2 resistors, the resistor in the current sampling part is the sampling resistor of the module output current, and one path of voltage drop signal of the resistor is directly sent back to the PWM control IC, so that the output current of the module is constant. The constant output current can protect the circuit from overlarge current output and also ensure the safe charging current of the charged lithium battery under low voltage; and the other path of current signal is amplified in a linear proportion by a current signal linear amplifier consisting of the other 3 resistors and an OP to be sent to the MCU, and an ADC of the MCU is used for precisely measuring the charging current. The charging controller composed of the triode and the field effect transistor MOS controls the triode through the MCU, the lithium battery charging is controlled by the MCU, and the lithium battery is charged under the condition that the MCU detects and determines that the polarity of the lithium battery is correct and the voltage range is proper.
The following is a principle description of the MCU controller and the display circuit.
The MCU main controller (namely STM 8) mainly realizes 7 functions of voltage measurement display, current and time unit multiplication operation, product accumulation and integration display, key input, display screen display parameter state and charging control.
The voltage sampling circuit's partial pressure signal sends to MCU's voltage measurement ADC passageway, becomes the partial pressure signal digital quantity through the ADC in the MCU, shows the voltage value by the display screen at last, and MCU is through the polarity condition to voltage sampling signal analysis access battery simultaneously, and the voltage range abnormal conditions acquires the exact signal voltage value for MCU output charge control signal.
The linear proportional amplifier composed of OP and peripheral components processes and amplifies the sampled current signal, so that MCU obtains the current signal input quantity corresponding to the current value and sends it to the current measuring ADC channel of MCU, the current signal is converted into digital quantity by ADC in MCU and displayed, meanwhile, the MCU and the measurement algorithm multiply the current digital quantity and the time quantum to obtain a capacity value in unit time, namely milliampere-hour, through the program written in by MCU and memory function, MCU multiplies the current digital quantity measured by each current sampling by time quantity, and temporarily stores the unit time milliampere-hour value, and accumulating and integrating (Fourier series calculation) when the MCU obtains the milliampere-hour value of the next unit time, finally accumulating and integrating the current signal value which is continuously changed in the charging process and the product number of the elapsed time into a total number, and displaying the obtained lithium battery capacity result by a display screen.
The display screen is composed of an LED nixie tube or an LCD (liquid crystal display) screen and an LED sign tube, and the MCU is used for displaying manual interface information such as voltage data, current data, capacity integrating data, lithium battery abnormal information codes, display type indication and the like.
The key input of the MCU is formed by the START key and the RESET key, so that the charge starting and the stop resetting of the charge process are realized.
The whole process is further described below.
1. After the charger is electrified, voltage can be set through the constant voltage and constant current module, or the charging voltage is set by using an external voltage regulator, so that the charging voltage accords with the charging voltage value of a charged lithium battery or a lithium battery pack, and the constant current value is set by the inside of the constant voltage and constant current module;
2. the charging voltage is transmitted to the input end of a digital-to-analog converter (ADC) of the MCU through a voltage sampling circuit, is converted into digital quantity through the ADC in the MCU and is transmitted to the MCU for operation and decoding, and finally, the voltage value is transmitted to a display screen for display;
3. as shown in fig. 2 and 3, after the charged lithium battery or lithium battery pack is connected with the correct polarity, the MCU detects and judges the battery state (battery terminal voltage, polarity) through the voltage sampling signal, and alarms the incorrect reverse polarity connection and the abnormal state of the battery voltage being too low, especially in the case of the reverse polarity connection, the charging process will not be performed;
4. as shown in fig. 2 and 3, when the MCU determines that the state of the lithium battery is normal, the charging control loop is opened to wait for a charging command, and after the charging command is pressed by the START key, an input signal enters the MCU, and charging and capacity metering are started;
5. after the charge capacity measurement is performed by current sampling and digital filtering once every 0.5 seconds, that is, fig. 2 shows that the current analog signal charged in the lithium battery is sent to the ADC port of the MCU, converted into a digital quantity by the ADC in the MCU, and simultaneously subjected to appropriate digital filtering to prevent a measurement error caused by an external interference signal, the MCU performs a maampere-hour multiplication operation once every 0.5 seconds on the current digital quantity, and an error value generated in a period of 0.5 seconds is less than 0.02% to satisfy the measurement requirement, and performs an additive integration on products of each time, thereby realizing the accumulation of the maampere-hour value of the charge capacity measurement, wherein theoretically, the shorter the unit time is, the smaller the error is, the more accurate the result is, but the product cost is increased, so that the period of 0.5 seconds is a value taking into account of the error and the measurement cost, while in the current charge capacity measurement method, the measurement period is long, such as 1 minute records an average value of 1 second, although the sampling is more, the average method is adopted, the number of actual sampling values is reduced, the error factor is increased, and the accuracy of the measured value is influenced;
6. the process of measuring the charging capacity is started by generating an electric signal after a START key is pressed down until the charging current is 0 after the lithium battery is fully charged;
7. the MCU samples the voltage and the current in the charging process, calculates the milliampere hour capacity, displays the voltage and the current on the display screen, memorizes the total charging capacity value after the charging is finished, and displays the total charging capacity value on the display screen.
8. When a charging error or other unknown problems occur, the RESET key is pressed to RESET the system state, and the RESET system state can be determined according to a program preset in the MCU or a program set by an external circuit.
In a preferred embodiment, the charger further includes an AC/DC converter, a constant voltage and constant current module, a charging loop, a voltage regulator, a current and voltage sampling module, and an input button.
Preferably, an ADC digital-to-analog converter, a digital filter and a calculator are arranged in the MCU.
Preferably, the input key includes a START of START signal and a RESET of RESET signal.
Preferably, the product value and the addition value in the steps 5 and 6 are in milliampere hours or ampere hours.
Preferably, the unit of the addition integration value finally obtained in the step 7 is ampere hour.
Preferably, the formula of the milliamp-hour multiplication is that the measured current value × is a unit time value = a milliamp-hour value or an amp-hour value in the unit time.
The invention has the beneficial effects that:
1. regardless of the state of the lithium battery or the lithium battery pack to be measured, the charging process is the process of measuring the capacity, and when the final measurement result is obtained, the charging is also finished, so that the lithium battery or the lithium battery pack can be used immediately, and the time is saved;
2. the charging value is directly calculated according to the real-time voltage and current value regardless of the influence caused by the constant voltage and the constant current state, and the real measured value is directly obtained by integrating the charging value, but not the calculated value of the average number, so that the calculation mode is simplified;
3. the charging device is not influenced by the charging environment, so that the charging device can be obtained, a user can conveniently know the real charging amount, the charging amount can be regarded as the capacitance, and the charging device is simple to operate and very practical.
In addition, the capacity of the battery can be directly charged and measured for the product without disassembling the measured battery in the electronic and electric product, so that the measuring working efficiency is greatly improved, and the method has the advantage that the method can be embodied.
The invention aims to abandon the original discharge mode for measuring the capacity, innovate the capacity precision calculation measurement in the lithium battery charging process, calculate the real capacity of the lithium battery, and control the uncertain factors of the lithium battery to the minimum degree in the whole charging and measuring process, thereby obtaining more accurate results.
However, in the currently known charging method for calculating capacity, for the protection of the lithium battery, charging is often stopped after a set current or voltage value, instead of adaptively controlling to obtain a terminal voltage according to the actual situation of the lithium battery, which may cause the problem that the battery cannot be fully charged, and a phenomenon of inaccurate capacity measurement, especially an aged battery, may occur, because of a voltage drop phenomenon superimposed on internal resistance, the result of measuring the terminal voltage is greatly affected, and the subjective theorization and mechanization of mode switching may occur for the sake of overall consistency in the constant-voltage constant-current switching of such charging methods, resulting in further increase of errors, and this charging capacity measurement method is not favorable for measuring the actual capacity of the lithium battery.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (7)
1. A capacity measurement method for a charging process, comprising the steps of:
step 1, connecting a charger into a circuit, setting a charging voltage value and a constant current charging current value which are in accordance with a charged battery or a battery pack, and entering step 2;
step 2, the charging voltage value is transmitted to an MCU arranged in the charger, the charging voltage value is processed by the MCU and then output as a display signal, the display signal is displayed by a display screen, and the step 3 is carried out;
step 3, the charged battery or the battery pack is connected to the charger with correct polarity, the MCU judges the voltage and the polarity of the charged battery or the battery pack, if the polarity is wrong, the MCU alarms and stops charging, if the voltage is too low, the MCU alarms and stops charging, and the MCU enters step 4;
step 4, the MCU enters a state of waiting for a charging instruction until a signal instruction for starting charging is input, and then the MCU enters step 5;
step 5, starting the charging process, converting the acquired analog signal of the charging current into a digital quantity by the MCU, carrying out sampling and digital filtering on the digital quantity every 0.5 second/time, carrying out milliampere-hour multiplication operation of 0.5 second/time to obtain a product value, carrying out addition integration on the product value obtained each time to obtain an addition integration value, and entering step 6;
step 6, the MCU displays the real-time voltage value, the charging current value and the addition integrated value in turn in the charging process according to the sequence, stores the real-time voltage value, the charging current value and the addition integrated value in the MCU, and enters step 7;
and 7, when the charging current value of the charged battery or the battery pack becomes 0, ending the charging process, outputting the finally obtained addition integrated value as a display digital value by the MCU, and displaying the display digital value by the display screen, wherein the display digital value is the size of the charging amount.
2. The method of claim 1, wherein the charger further comprises an AC/DC converter, a constant voltage and constant current module, a charging loop, a voltage regulator, a current and voltage sampling module, and an input button.
3. The method of claim 1, wherein an ADC digital-to-analog converter, a digital filter and a calculator are disposed in the MCU.
4. The method of claim 2, wherein the input button comprises a START signal and a RESET signal.
5. The method of claim 1, wherein the multiplication value and the addition multiplication value in the steps 5 and 6 are expressed in milliampere hours or ampere hours.
6. The method for measuring capacity during charging according to claim 1, wherein the unit of the additive integrated value finally obtained in step 7 is ampere-hour.
7. The method of claim 1, wherein the milliamp-hour multiplication is formulated as × unit time values of measured current values = milliamp-hour values or amp-hour values in the unit time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010421031.XA CN111337840A (en) | 2020-05-18 | 2020-05-18 | Capacity measuring method in charging process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010421031.XA CN111337840A (en) | 2020-05-18 | 2020-05-18 | Capacity measuring method in charging process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111337840A true CN111337840A (en) | 2020-06-26 |
Family
ID=71184919
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010421031.XA Pending CN111337840A (en) | 2020-05-18 | 2020-05-18 | Capacity measuring method in charging process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111337840A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113809790A (en) * | 2021-08-05 | 2021-12-17 | 惠州市蓝微电子有限公司 | Multi-battery pack charging method, charging monitoring method and device |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1756963A (en) * | 2003-03-03 | 2006-04-05 | 索尼爱立信移动通讯股份有限公司 | Apparatus and method for charging battery cells |
| CN103454509A (en) * | 2012-05-30 | 2013-12-18 | 联芯科技有限公司 | Mobile phone charging detecting system and mobile phone charging detecting method |
| CN105006871A (en) * | 2015-08-26 | 2015-10-28 | 广东欧珀移动通信有限公司 | Method for simulating real battery charging process and device thereof |
| CN110133519A (en) * | 2019-05-28 | 2019-08-16 | 蜂巢能源科技有限公司 | Calculation method, device and the equipment of battery capacity |
-
2020
- 2020-05-18 CN CN202010421031.XA patent/CN111337840A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1756963A (en) * | 2003-03-03 | 2006-04-05 | 索尼爱立信移动通讯股份有限公司 | Apparatus and method for charging battery cells |
| CN103454509A (en) * | 2012-05-30 | 2013-12-18 | 联芯科技有限公司 | Mobile phone charging detecting system and mobile phone charging detecting method |
| CN105006871A (en) * | 2015-08-26 | 2015-10-28 | 广东欧珀移动通信有限公司 | Method for simulating real battery charging process and device thereof |
| CN110133519A (en) * | 2019-05-28 | 2019-08-16 | 蜂巢能源科技有限公司 | Calculation method, device and the equipment of battery capacity |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113809790A (en) * | 2021-08-05 | 2021-12-17 | 惠州市蓝微电子有限公司 | Multi-battery pack charging method, charging monitoring method and device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0225106B1 (en) | Battery state of charge indicator | |
| US7821232B2 (en) | Method of calculating remaining capacity of rechargeable battery | |
| EP2535729A1 (en) | Battery charge determination | |
| CN1228540A (en) | Monitoring technique for accurately determining residual capacity of battery | |
| WO2019140956A1 (en) | Electricity quantity metering accuracy detection method, device and computer storage medium | |
| CN111740464B (en) | Battery power compensation method, device, equipment and readable storage medium | |
| US20080252262A1 (en) | Device And Method For Charging And Controlling The Charge Of A Battery | |
| JPH08278351A (en) | Device for measuring remaining capacity of battery | |
| CN111337840A (en) | Capacity measuring method in charging process | |
| US6049193A (en) | Method and device for executing a battery auto-learning | |
| CN101865959A (en) | Charger detector of electric vehicle | |
| CN108363012B (en) | System and method for detecting faults of key devices of starting power supply of lithium battery for vehicle | |
| CN212808554U (en) | Display device for battery electric quantity | |
| CN112147523B (en) | Button cell allowance measuring method and measuring device | |
| TW201901179A (en) | Battery fuel gauge circuit | |
| JPS61209373A (en) | Circuit for confirming residual power quantity in battery | |
| CN113447830A (en) | Method and device for monitoring electric quantity of lithium battery of wireless intelligent sensor | |
| CN102207517B (en) | Method for testing mean current of circuits by Farad capacitor | |
| CN207473067U (en) | A kind of passive intelligent accumulator capacity detector | |
| JPS63208773A (en) | Monitoring device for remaining capacity of storage battery | |
| CN219777880U (en) | Battery electric quantity detection and display device | |
| JPH11101832A (en) | Capacitance-measuring instrument | |
| CN2064068U (en) | Digital display metering installation for accumulator capacity | |
| JPH04140678A (en) | Method for monitoring amount of remaining power of secondary cell | |
| CN219039318U (en) | Battery electric quantity metering device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200626 |
|
| RJ01 | Rejection of invention patent application after publication |