What Is The Lithium Battery Life? By Year or Cycle Times?
When we talk about lithium battery life, it refers to cycle life and calendar life. Cycle life refers to the number of times the battery can be charged and discharged in cycles. That is, under ideal temperature and humidity, charge and discharge with rated charge and discharge current, and calculate the number of cycles experienced when the battery capacity decays to 80%.
The calendar life refers to the time span for the battery to reach the end of life condition (capacity decays to 80%) under specific operating conditions under the environmental conditions of use. The calendar life is closely combined with specific use requirements, and it is usually necessary to specify specific use conditions, environmental conditions, storage intervals, etc.
Cycle life is a theoretical parameter, and calendar life is more practical. Different charging and discharging methods have different effects on the life of the battery.
Except for the above use condition which would greatly affect battery life, there’s another important factor-consistency of the battery pack. What is it? See Bonnen engineer explaining.
Consistency of The Battery Pack
After the battery cell is manufactured, due to process problems, the internal structure and material are not completely consistent, and there are certain performance differences between battery cells.
The initial inconsistency accumulates with the continuous charge and discharge cycles of the battery during use, and the use environment in the battery pack is also different for every single cell, resulting in greater differences in the status of each single battery cell. Gradually amplify during use, so that in some cases, the performance of certain single cells will be accelerated, and eventually lead to premature failure of the battery pack.
It should be pointed out that the performance of the power battery pack is determined by the performance of the battery cells, but it is by no means a simple accumulation of the performance of the single cells. Due to the inconsistency of the performance of the single cells, when the power battery pack is repeatedly used in an electric vehicle, the life is shortened.
In addition to strictly controlling the process and keeping the consistency of single cells as much as possible in the production and assembly process, the current industry generally uses battery management systems with balancing functions to control the consistency of the batteries in the battery pack to extend the product Service life.