How to "select" batteries for saic electric cars

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but also neat and beautiful. On the other hand, the battery in the "elderly scooter" is unbearably simple and crude.

It is not easy for new energy car manufacturers to build a good car, which requires excellent performance in every major aspect and no ambiguity in the details of the product.

For example, when it comes to the details of the battery, a good electric car battery is not only safe and reliable, but also neat and beautiful. On the other hand, the battery in the "elderly scooter" is unbearably simple and crude.

So how does a perfect battery come about from a car manufacturer's point of view? Why are there so many differences between battery manufacturers?

Small make up also feels curious to this problem, asked engineer young associate designarily then, talk about this problem briefly below.

What is this big black thing?

Electric cars have nice, neat looking batteries, but when you turn them on and look inside, you'll see clumps of black. What are these black things?

Let me tell you, they are the basic cell - battery module.

Does that sound complicated? No matter, the charm of industrialization lies in the simplification of complex products. Even complex products can be decomposed and then produced and assembled according to unified standards.

Battery modules are no exception and are produced and assembled based on uniform standards. At present, the most popular standard in the world is the VDA standard.

Wait, what is the VDA standard?

VDA

Is the abbreviation of VerbandderAutomobilindustrie, mean the German automotive industry association. They define a series of cell size standards, meet the size of the standard cell module, called the VDA module.

In short, keep in mind that this is a set of industry standards. At present, the standard has been unified.

How has adoption changed the industry?

Before VDA came into being, there were various specifications for power batteries, as shown in the figure below:

Colorful, disorganized...

Under such conditions, it is difficult for manufacturers in the industrial chain to effectively coordinate with each other and form economies of scale.

After the adoption of VDA standard, the cell can be mass produced, and the economic benefits will ultimately benefit the whole industry:

First of all, from the perspective of the vehicle manufacturers, under the unified standard, the vehicle manufacturers can purposefully design battery packs, and can compare the cells produced by different cell manufacturers based on the unified specifications, so as to match the best cell products for the vehicle models. That's the same reason we're familiar with the no. 5 battery for our remote control and the standard battery for our laptop.

Second, from the perspective of the cell supplier, under the condition of unchanged vehicle and battery structure, the cell supplier can concentrate resources to launch better cells and can also iterate and upgrade very quickly. For example, the capacity of a six-core laptop purchased today is 50% higher than that of five years ago.

Two VDA routes and five specifications

The VDA cell is divided into EV and PHEV two routes, a total of 5 specifications. In the case of the ERX5 battery, we use the PHEV2.

With the standard VDA cell module, is it possible to purchase and install it?

Of course not. The vehicle manufacturers also need to be in a variety of, uneven cell selection, this is almost the most important watershed to witness the strength of different automobile manufacturers.

Hold your breath.

Cell selection is like choosing a vegetable

For more vda batteryinformation, please contact us. We will provide professional answers.

It is said that a aspiring chef has strict requirements for ingredients. < / p > < p > ono Erlang every day personally to the wharf to buy fish, rice, vinegar, soy sauce... The producing area of food material, fresh degree, want to pass careful choose, repeatedly research, ability presents the most perfect meal for the customer.

Similarly, a promising new energy vehicle manufacturer has similarly stringent screening criteria for cell modules. Taking saic as an example, in addition to selecting the top suppliers in the industry, saic also strictly selects the modules provided by suppliers.

Saic cell detection indicators include OCV detection, self-discharge, internal resistance, capacity sampling, etc., which are strictly checked by engineers.

Why such a rigorous screening?

We all know the "short board principle" -- the part of the cell where the short board is located determines thespecial effectiveness of the entire battery. A small part of the inadequate capacity of the cell, after a long time of unreasonable use, will greatly accelerate the aging of the cell. It can be said that the 1% difference in capacity at the beginning will continue to increase significantly with the use of time.

After introducing a strict screening process, saic will first conduct consistent screening and grouping according to the time when the modules leave the factory to ensure that the modules of the same batch are combined together, so as to minimize the differences.

Saic will continue to screen and test some cells that are quite different from the modules to ensure the consistency of the cells in the whole battery.

Therefore, when the quality level of battery manufacturers fluctuates, the battery module of saic's own brand can always strictly observe the quality level, ensuring the overall consistency of the product, which is also an important source of confidence in the "8 years 200,000 km" attenuation quality assurance commitment.

Iron bone also has tenderness layers of protection highlights safety

Through the layers of rigorous screening, choose a good cell, is it all right?

That's not enough. For power batteries, it is not only simple to put the battery cell in, how to protect the battery cell, is also a very challenging work.

Saic has a complete battery safety protection mechanism to create a "four-fold protection" of battery safety to ensure the safe use of car owners.

Protection 1: protection of the lower layer aluminum plate and anti-stone impact design

In the running of a car, the position of the car bottom and wheel fender is easy to be impacted and washed by mud, sand, gravel and sewage. In this case, the general coating is easy to damage, so it is easy to lose the protective ability, so that these parts quickly corrosion.

As the battery system is directly arranged under the car, in order to prevent external damage to the aluminum alloy shell, the anti-stone impact coating adopted by saic has the characteristics of anti-sand impact and anti-corrosion.

Protection 2: body side and front frame

The frame on the side and front of the vehicle is mainly made of aluminum alloy, which has a series of characteristics and competitive advantages, such as low density (2.7g/cm3), high strength, good heat dissipation and conductivity, excellent processing and forming performance, corrosion resistance, mature technology, high recovery and regeneration rate.

The 6-series aluminum profile has good plasticity and corrosion resistance, especially no stress corrosion cracking tendency and good welding performance.

Protection 3: lightweight design combined with structural strengthening

The structure design is strengthened, especially the internal structure design, so that the battery box can bear the weight of the battery module, and also match the mechanical requirements of the vehicle.

In terms of structural design, saic considers the modal performance of the lower shell, and through the monitoring of modal frequency and vibration mode, the dynamic stiffness characteristics of the structure can be determined. By means of complete design simulation and experiment, it can meet the requirements of vibration and impact of battery system, and form a perfect combination with the whole vehicle system.

Protection 4: combination of battery system and vehicle system

Through the simulation design of the whole vehicle, the collision safety of the whole vehicle and the battery system is guaranteed when the vehicle encounters emergency and accident.

Through the above careful safety protection design, saic's new energy vehicle battery can finally keep safe in all kinds of harsh scenarios.

Let's take a look at the effects of a real crash test:

For the battery of electric cars, the front and rear parts of the body have more protection, the side of the body protection is very difficult. In the absence of a separate side impact regulation in China, the roewe ERX5 challenges the most stringent European standard for side column impact tests.

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