What Does Battery Consistency Mean?

 

The meaning of battery consistency

Battery consistency is an important concept in the battery field. It is of great significance to many fields such as electric vehicles and energy storage systems. Battery consistency refers to the consistency of the initial performance indicators of the single cells used in the group, including capacity, electrical impedance, electrical characteristics of the electrode, electrical connection, temperature characteristics, decay rate, etc. The smaller the degree of this difference, that is, the better the consistency, the better the overall performance of the battery pack.

The importance of battery consistency

 

1. Affecting the performance of the battery pack.

The capacity of each single cell in the battery pack cannot be exactly the same. The better the consistency, the higher the total energy utilization rate of the battery pack when it is working, and the greater the energy storage density. If the battery consistency is poor and the battery capacity difference is large, the battery with small capacity will become the bottleneck of the battery pack, resulting in a decrease in the total energy utilization rate of the battery pack, a decrease in the energy storage density, and a decrease in the performance of the entire battery system.

 

2. Affecting the life of the battery pack.

If the battery internal resistance error is large, the battery with large internal resistance will generate more heat when working, causing the battery temperature to rise when working, reducing the battery life. In addition, if the internal resistance error of different batteries is large, the battery is prone to inconsistent single cell voltage when overcharged or over-discharged, accelerating the loss of battery life.

 

3. Safety issues.

There are some uncontrollable factors inside the battery, such as uneven distribution of materials and differences in physical structure. Low-consistency batteries are prone to safety hazards during use. Some batteries may be damaged by explosions or fires during fast charging or overload discharge, resulting in serious consequences such as casualties and property losses.

Standards for battery consistency

 

1. Voltage consistency:

Under the same charging or discharging state, the voltage difference of each single cell in the battery pack should be as small as possible. Generally speaking, the smaller the voltage difference, the better the battery consistency.

 

2. Capacity consistency:

The rated capacity of each single cell in the battery pack should be as close as possible. In actual use, a battery pack with a smaller capacity difference can distribute current more evenly and improve overall performance.

 

3. Internal resistance consistency:

Internal resistance is one of the important indicators for measuring battery performance, and the internal resistance difference of each single cell in the battery pack should also be as small as possible.

Battery packs with good internal resistance consistency can reduce energy loss and heat generation during charging and discharging, and improve efficiency and safety.

 

4. Temperature consistency:

The temperature difference of each single cell in the battery pack should be as small as possible to avoid performance differences caused by temperature differences.

Battery packs with good temperature consistency can distribute heat more evenly and extend service life.

 

5. Cycle life consistency:

The cycle life of each single cell in the battery pack should be as close as possible.

Battery packs with good cycle life consistency can maintain overall performance for a longer time and reduce maintenance costs.

 

6. Safety consistency:

The safety of each single cell in the battery pack should be consistent, including protection performance such as overcharge, over discharge, and short circuit.

Battery packs with good safety consistency can reduce the occurrence of safety accidents and improve the safety of use.

 

7. Appearance and size consistency:

The appearance and size of each single cell in the battery pack should be consistent for easy installation and fixation. Battery packs with good appearance and size consistency can improve the overall aesthetics and stability.

In actual applications, the quality of battery consistency may vary depending on the specific application scenario and needs. Therefore, when designing and manufacturing battery packs, it is necessary to formulate corresponding consistency standards and test methods according to actual needs. At the same time, during the use and maintenance of the battery pack, it is also necessary to regularly check the consistency of the battery, find problems in time, and take corresponding measures to repair or replace them.

 

This translation is based on the original work by Battery manufacturing engineer. Translated by Jessie.