In the lithium battery module, several single cells are connected into a power supply in series and parallel through conductive connectors, and are fixed in the design position through the process and structure to play the function of power charging and storage. It can be said that the basic role of the module is to connect, fix and security protection. The connection mode between the cell and the module mother of the battery not only affects the manufacturing efficiency, but also affects the performance of the battery after loading.

Lithium battery module can be understood as the intermediate product of lithium ion cell and pack formed by combining it in series and parallel mode. Its structure must play a supporting, fixed and protective role in the cell, which can be summarized into three major items: mechanical strength, electrical performance, thermal performance and fault handling ability. Whether the battery can fix the position of the cell and protect it from destructive deformation, how to meet the requirements of current carrying performance, and how to meet the control of the cell temperature, will be the standard to judge the quality of the lithium battery module.

The whole process of lithium battery module design includes the objectives of module design, integrating the details of module design, and having a complete verification process of module design, including structure, electrical and cooling safety.

The first part is divided into several design levels：

To meet the demand characteristics of the vehicle is equivalent to the product, mainly divided into structural design, electrical design, thermal design, safety design, according to the requirements of the cell to give enough pressure, through a certain pressure can effectively prevent the expansion of the cell, in the life to give a certain support.

The second part, the manufacturing process：

The most important is the cell from the single to stacking, welding, sampling line layout, CMU layout, the whole process and equipment assembly have specific requirements.

The third part, maintenance consideration：

The first step is to make the product. In the later stage, with the use of the vehicle, the maintenance of the whole lithium battery module, especially the damage of the sub-parts inside, should be combined with the manufacturing process and maintenance process.

Key points of lithium battery module structure design:

Reliable structure of lithium battery pack: vibration resistance;

Process controllable: no excessive welding, virtual welding, to ensure that the cell is 100% without damage;

Low cost: promote the automation of PACK production line, including production equipment and production loss;

Easy separation: lithium battery module is easy to maintain, repair, low cost, good use of battery cells;

To achieve the necessary heat transfer isolation to avoid the rapid spread of heat runaway, you can also consider this step into pack design.

The unique advantages of the BOSA lithium battery module：

1)  TUV, UL, UN38.3, MSDS, CCS certification;  

2) The module has temperature and voltage sensor pre-welded with wiring to the BMS, connection with BMS is "plug and play" type;

3) The module is of standard design and mature manufacture which has 40K electric vehicle/100Mwh ESS and yachts application experience;

4) It's universal to all BMS, not limited to BMS types;

5) It's flexible in configuration, 8 Pcs cell could be 1P8S 25.6V, 2P4S12.8V;

6) Modules are connected by Busbar and bolts into battery system.

It is understood that at present, the module composition efficiency of cylindrical cells in the industry is about 87%, the system group efficiency is about 65%; the module composition efficiency of soft package cells is about 85%, the system group efficiency is about 60%; the module composition efficiency of square cells is about 89%, and the system group efficiency is about 70%. At present, the square cell module is indeed an optimal choice.