The bad thing about the battery system is that its chemical system is affected by the environment. Whether the battery or electric control, as long as the car must be in accordance with the requirements of the automotive core components. A very important point of V model development is the layered design, layered verification, such as management system is a small part, the need to add management system, design and development, wait until the management system test verification, do pack integrated design, and then do the integrated vehicle design, is a layer of very rigorous development design process.
1. Mechanical design. PACK GBT31467.3 has 16 safety tests, as well as fire and squeeze tests. In terms of pack, reduce cost, reduce weight, ensure security and reliability of contradictions, in the security design, not only consider the cost, but also consider the safety, energy density. Pack weight reduction, to consider the mechanical strength, mechanical life, anti-corrosion, to ensure reliability.
The importance of 2.IP67. IP67 is involved in security, not only can use, but also security. Analyze the control of IP67 in several aspects, first look at the box processing, to ensure that the box will not be destroyed; the other is to look at the pressure balance valve, can guarantee different latitude, different temperature, inside and outside of the air pressure to maintain balance; three is the upper and lower cover sealing surface, need to consider whether flame-retardant, sealing good, in addition to material selection, shape selection, There is a fixed compression ratio; Four, the connector is easy to leak, mainly wiring harness, wire and plug relationship, Plug and socket relationship, socket and box relationship. To pay special attention to design, the connector base of the fixed way to use blind holes, if the need for blind holes, and the box inside the design is not blind hole, and then add glue is not used, in the long run is not. In addition, the installation of connectors, the plane of the box is required, when the structural design is unreasonable, connector base and electric box seals will also leak.
3. Battery thermal management design. Battery Thermal management design is divided into three major steps. The first step is to establish a thermal model. After the model, a single battery is specially tested for hot spots, the relationship between the power and the heating model is established, and the second step is the system thermal design. From the layout of the mechanical structure, the heat conduction path, calculate its thermal resistance loop; The third step is thermal management and strategy, one purpose is to prevent heat out of control, to ensure safety, another purpose is to battery long life, control some application power, to prevent the battery at a higher temperature.
4. water-cooled + hot and cold management system. The application of high temperature zone has refrigeration system, cold water, heating system and heating water. There is a switching function between the two. However, at present even to make this product, can only say to use, still imperfect. The solution has two directions: low temperature batteries and fast heat technology.