3.7v 18650 battery pack

　　Can balanced charging of 3.7v 18650 battery pack the problem of battery consistency?

　　Lithium battery pack charging characteristics

　　In the power battery pack, there is inconsistency between individual cells. The differences caused by continuous charge and discharge cycles will accelerate the capacity decay of some single cells. The capacity of the series battery pack is determined by the minimum capacity of the single cell, so these differences will shorten the service life of the battery pack. The main reasons for this imbalance are:

　　●During the battery production process, due to process and other reasons, there are differences in capacity, internal resistance, etc. of batteries in the same batch;

　　●Differences in battery self-discharge rates, accumulated over a long period of time, result in differences in battery capacity;

　　●During battery use, differences in usage environment such as temperature and circuit boards lead to imbalance in battery capacity.

　　Balanced charging of lithium battery packs effectively improves battery consistency issues

　　As a new power technology, lithium battery packs must be connected in series to meet the voltage requirements. The uneven performance of individual cells is not entirely due to technical issues in battery production. Even if each battery leaves the factory with exactly the same voltage and internal resistance , differences will also occur after being used for a period of time, which makes solving the technical problem of power battery charging an urgent technical issue that needs to be solved.

　　In order to solve the consistency problem in the use of power lithium battery packs, this article proposes an implementation plan for a balanced charging management circuit. First, the characteristics of a single lithium battery are analyzed; then, based on comparing various balanced charging theories, the partial shunt method is selected as the design idea and the specific circuit design is carried out. Multiple lithium battery pack charging and discharging experiments have shown that this balanced charge management circuit can effectively improve the charging consistency of the lithium battery pack, improve the battery pack's working performance, and extend its service life.

　　Due to the problem of inconsistent battery performance, the performance of battery packs in terms of utilization, service life, safety, etc. is far inferior to that of single batteries. The lithium battery management system with efficient balancing management function can greatly improve the overall performance of the power battery pack, effectively extend the service life of the lithium battery pack, and greatly reduce the use and maintenance costs of the entire vehicle. Provide technical support for the promotion of safe, efficient and practical electric vehicles.

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