Do you know the inconsistency mechanism of lipo 6s battery 100c in groups?

This is an article introducing lipo 6s battery 100c group inconsistency, what is lipo 6s battery 100c group inconsistency, and the effect of lipo 6s battery 100c group inconsistency and lipo 6s battery 100c group inconsistency cause.

lipo 6s battery 100c group inconsistency

The inconsistency of the lipo 6s battery 100c group refers to the differences in the capacity, voltage, internal resistance, self-discharge rate and other parameters of the single battery. caused.
After the single lipo 6s battery 100c is grouped, the cycle life will be reduced. Choosing a single lipo 6s battery 100c with a longer service life to combine into a battery pack will increase the cycle times of the lipo 6s battery 100c group, but in order to improve the overall performance of the battery pack and obtain a longer service life, attention should also be paid to the single lipo 6s battery 100c matching consistency, providing suitable working conditions and adopting proper thermal management measures for timely repair and maintenance.

The effect of lipo 6s battery 100c group inconsistency

The inconsistency of the lipo 6s battery 100c will affect the service life of the battery pack and reduce the performance of the battery pack. Next, a professional lipo 6s battery 100c manufacturer will analyze the reasons for the inconsistency of lithium-ion battery packs.

lipo 6s battery 100c group inconsistency mechanism

1 Parameter difference between single lipo 6s battery 100c

The state difference between the single lipo 6s battery 100c mainly includes the initial difference of the single battery and the parameter difference generated during use. There are many uncontrollable factors in the design, manufacture, storage and use of lipo 6s battery 100c, which will affect the consistency of lipo 6s battery 100c. Improving the consistency of the single lipo 6s battery 100c is a prerequisite for improving the performance of the battery pack. The interaction of the parameters of the single battery, the current parameter state is affected by the initial state and the cumulative effect of time.

1) lipo 6s battery 100c capacity, voltage and self-discharge rate

The inconsistency of the 100c capacity of the lipo 6s battery (What is the capacity of 11.1v lipo battery?) will make the depth of discharge of each single cell of the battery pack inconsistent. The lipo 6s battery 100c with smaller capacity and poor performance will reach the fully charged state in advance, resulting in the lipo 6s battery 100c with large capacity and good performance not being able to reach the fully charged state.

The inconsistency of the battery voltage will cause the single cells in the parallel battery pack to charge each other. The lipo 6s battery 100c with higher voltage will charge the battery with lower voltage, which will accelerate the degradation of battery performance and consume the energy of the entire battery pack. A battery with a high self-discharge rate has a large capacity loss, and the inconsistency of the self-discharge rate of the battery will lead to differences in the state of charge and voltage of the battery, which will affect the performance of the battery pack.

2) lipo 6s battery 100c internal resistance

In the series system, the internal resistance difference of the single lipo 6s battery 100c will cause the charging voltage of each battery to be inconsistent. The lipo 6s battery 100c with a large internal resistance reaches the upper voltage limit in advance, and other batteries may not be fully charged at this time.

A battery with a large internal resistance has a large energy loss and generates a high amount of heat, and the temperature difference further increases the internal resistance difference, resulting in a vicious circle.
In a parallel system, the internal resistance difference will lead to inconsistencies in the current of each battery, and the voltage of the lipo 6s battery 100c with a large current changes rapidly, making the charging and discharging depth of each single lipo 6s battery 100c inconsistent, making it difficult for the actual capacity value of the system to reach the design value. . The battery operating current is different, and its performance will vary during use, which will ultimately affect the life of the entire battery pack.

2 lipo 6s battery 100c charging and discharging working condition

The charging method affects the charging efficiency and charging status of the lipo 6s battery 100c group. Overcharging and overdischarging will damage the battery, and the battery pack will show inconsistency after multiple charging and discharging. At present, there are several ways to charge lipo 6s battery 100c , but the common ones are segmented Constant current charging method and constant current and constant voltage charging method.

Constant current charging is an ideal method, which can be fully charged safely and effectively; constant current and constant voltage charging effectively combines the advantages of constant current charging and constant voltage charging, and solves the problem that the general constant current charging method is difficult to fully charge accurately. It avoids the influence of the constant voltage charging method on the lipo 6s battery 100c caused by the excessive current in the early stage of charging, and the operation is simple and convenient.
Regarding the discharge content of lipo 6s battery 100c, the following article has a detailed introduction:
lipo battery 3s self-discharge dry goods!

3 lipo 6s battery 100c temperature

The performance of lipo 6s battery 100c will be significantly reduced at high temperature and high discharge rate. This is because when the lipo 6s battery 100c is used under high temperature conditions and high current, it will cause the decomposition of the positive active material and the electrolyte, which is an exothermic process, and the release of such heat in a short time can cause the temperature of the lipo 6s battery 100c itself to further increase , the temperature rise accelerated the decomposition phenomenon, forming a vicious circle, and the accelerated decomposition further reduced the performance of the lipo 6s battery 100c. Therefore, if the thermal management of the lipo 6s battery 100c group is improper, it will bring irreversible performance loss.

Differences in the design and use environment of the lipo 6s battery 100c group will cause the temperature environment of the single battery to be inconsistent. According to Arrhenius's law, the electrochemical reaction rate constant of lipo 6s battery 100c has an exponential relationship with the degree, and the electrochemical characteristics of lipo 6s battery 100c are different at different temperatures. Temperature will affect the operation, coulombic efficiency, charge and discharge capability, output power, capacity, reliability and cycle life of the lipo 6s battery 100c electrochemical system. At present, the main research is the quantitative research on the effect of temperature on the inconsistency of the lipo 6s battery 100c group.

4 lipo 6s battery 100c external circuit

1) Connection method

In the scale energy storage system, the lipo 6s battery 100c will be combined in series and parallel, so there will be many connection circuits and control elements between the lipo 6s battery 100c and the module. Due to the different performance and aging speed of each structural component or component, as well as the inconsistent energy consumption of each connection point, the impact of different components on the battery is different, resulting in inconsistencies in the lipo 6s battery 100c group system.

Inconsistencies in battery decay rates in parallel circuits can accelerate system deterioration.
The impedance of the connecting piece will also affect the inconsistency of the battery pack. The resistance value of the connecting piece is not the same. The longer the resistance value is, the smaller the current is. The connecting piece will make the single battery connected to the pole reach the cut-off voltage first, which will reduce the energy utilization rate and affect the battery performance. Moreover, the premature aging of the single battery will lead to The battery connected to it is overcharged, causing a safety hazard.
As the number of cycles of the lipo 6s battery 100c increases, the ohmic internal resistance will increase, the capacity will decay, and the ratio of the ohmic internal resistance to the connecting piece resistance will change. In order to ensure the safety of the system, the influence of the resistance value of the connecting piece must be considered.

2) BMS input circuit

The battery management system (BMS)  is the guarantee for the normal operation of the lipo 6s battery 100c group, but the BMS input circuit Will adversely affect the consistency of the lipo 6s battery 100c. The voltage monitoring methods of lipo 6s battery 100c include precision resistor divider, integrated chip sampling, etc. Due to the existence of resistors and circuit board paths, these methods cannot avoid external load leakage current of the sampling line, and the voltage sampling input impedance of the battery management system will increase the battery load. The inconsistency of the state of charge (SOC) affects the performance of the lipo 6s battery 100c group.

5 lipo 6s battery 100cSOC estimation error

SOC (about lipo 6s battery 100cSOC The following article has a detailed introduction, if necessary, you can read it yourself: 6s 6200mah lipo management system and 6s 6200mah lipo SOC The reasons for the inconsistency are the inconsistency of the initial nominal capacity of the single lipo 6s battery 100c and the work The nominal capacity fading speed of medium single cells is inconsistent. For a parallel circuit, the internal resistance difference of the single cells will cause uneven current distribution, which will lead to inconsistency in SOC. SOC algorithms include ampere-hour integration method, open circuit voltage method, Kalman filter method, neural network method, fuzzy logic method, discharge test method, etc.

The ampere-hour integration method has better accuracy when the initial state of charge SOC0 is relatively accurate, but the coulombic efficiency is greatly affected by the state of charge, temperature and current of the lipo 6s battery 100c, and it is difficult to measure accurately. Therefore, the ampere-hour integration method It is difficult for the method to meet the accuracy requirements of the state of charge estimation. Open circuit voltage method After standing for a long time, the open circuit voltage of lipo 6s battery 100c has a definite functional relationship with SOC, and the estimated value of SOC is obtained by measuring the terminal voltage. The open-circuit voltage method has the advantage of high estimation accuracy, but the disadvantage of long standing time also limits its application range.

Well, the above is the whole content of the lipo 6s battery 100c group inconsistency that CNHL brought to you today. The lipo 6s battery 100c group inconsistency refers to the capacity, voltage, internal resistance, self-discharge rate, etc. of the single battery. The difference in parameters is caused by the difference in the combined structure of the battery pack, operating conditions, operating environment, and battery management. The inconsistency of the lipo 6s battery 100c will affect the service life of the battery pack and reduce the performance of the battery pack. If you want to read more lithium-ion battery information, please click below:
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