Warranty knowledge of electric vehicle battery system

The electric vehicle battery system is at the stage of domestic new energy vehicle warranty. For vehicle companies, how to ensure that key components such as the power lithium-ion battery, motor, and electrical control of new energy vehicles are supplied with a warranty of no less than 5 years or 100,000 kilometers. The reasonable size of the vehicle is a big topic. From the perspective of battery system composition, it can be divided into three parts: 1) Battery module: including battery cells, current motherboard, cooling plate, sampling line, etc., as well as the mechanical part of the module itself. 2) Electronic system: battery processing main unit , Battery processing sub-units, current sensors, battery distribution units, etc. 3) Mechanical parts: battery holders, battery covers, screws, fixtures, etc. If we consider IPTV (warranty conditions per 1,000 cars) according to each component, it assumes that the battery is The scale of the total IPTV system is 1-5 years X1, X2, X3, X4, X5 failure rate curve and ordinary life, the entire battery system is mainly concentrated in the module. The first reason is that electronic systems and mechanical systems can be designed and manufactured with very low failures through robustness tests; regarding a battery system, there are different devices (parallel and series), and various failure conditions, such as capacity If the drop is particularly severe, or the internal resistance rises sharply, the entire battery system must be repaired. In the planning process, although a large number of users are covered, after all, for many automobile companies, due to the cycle life and service life of battery cells, the entire data stack is not rich. Okay, then the problem is coming. A start-up car manufacturer sold 1,000 cars, and gradually sold 10,000 cars, increasing to 100,000 cars. If the continued warranty period is five years, how to guarantee the entire repair process? ? This is actually an extreme example. Let’s take 800 E6 pure electric taxis from Shenzhen Pengcheng Electric Vehicle Leasing Co., Ltd. as an example: the relevant transaction volume in 2013 was 29.75 million yuan (new energy products + 21.64 million charging equipment + labor cost 811 10,000) The annual turnover of 2014 was 36.15 million yuan, all of which were labor costs. This work should not be carried out here, just to protect the cost of 800 vehicles. In 2014, an average of 45,100 yuan was shared. If it is a private car, the cost of the entire protection can be estimated based on the cumulative intensity of 10-30%. In terms of battery system protection, it can also be divided into the following categories: 1) Battery replacement In fact, the plan to replace the battery pack was the most common in the early days. The 4S shop closest to the private customer can handle the customer's problem car as soon as possible after replacing the battery pack or repairing it. The time period for equipment and training personnel is undoubtedly the shortest. The damaged battery pack is transported by land to the original battery pack factory or after-sales battery pack processing factory. Advantages and disadvantages + fast response speed, easy layout of 4S stores, low cost, large scale of protective cover-replacement battery packs must be shipped to the Smyrna plant in the United States-globally, the cost of moving the plant is relatively high 2) Replacement Battery module For example, in the practice of the BMWI series, the after-sales system of electric vehicles is arranged in a special 4S shop, and it is important to have special battery removal tools, such as the battery lifting tool in the picture on the bottom left; some modules are arranged in the 4S shop, each The module is 25kg and can be replaced directly. Advantages and disadvantages analysis of larger-scale cover + short repair time, compared with 5 hours of repair, active E is 25 hours + protection manpower is low, a technician can achieve replacement-the capacity is difficult to match, the battery system software and battery characteristics Higher requirements-higher layout costs, higher personnel training requirements 3) This method is difficult to implement in a 4S shop in a single unit. The important difficulty lies in the welding of the battery unit and the bus bar connection row, which cannot be repaired. Repair the module It also involves technical issues. In the final analysis, with the development of the new energy vehicle business, vehicle companies must have deeper thinking about the in-depth involvement of batteries and battery systems in the future. Let me analyze it for you. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Analysis of new energy vehicle power lithium-ion battery technology