In the details of battery handling, the battery of a good electric car is not only safe and reliable, but also has a neat and beautiful appearance. In contrast, the battery of the "Early Escalator" is simple and rough, making it impossible for people to look at it.
For new energy car manufacturers, it is not easy to build a good car. Besides demanding outstanding performance in all major aspects, the product details must not be vaguely ambiguous.
For example, in the details of battery handling, the battery of a good electric car is not only safe and reliable, but also has a neat appearance and is pleasing to the eye. In contrast, the battery of the "Early Escalator" is simple and rough, making it impossible for people to look at it.
So, from the car manufacturer's point of view, how did a perfect battery come into being? Why are the battery gaps between different manufacturers so large?
Xiao Bian is also curious about this issue, so he specifically consulted an engineer partner. The following is a brief discussion on this issue.
What is this black thing?
The battery of an electric car has a neat appearance, but if you look at its internal structure, you will find a black thing. What are these black things?
Xiaobian tells you, they are the basic unit consisting of batteries - battery modules.
Very esoteric wood? Indeed, let's first intuitively feel its internal structure:
Is it a bit complicated? It does not matter that the charm of industrialization lies in the fact that it is simple and complex. Even complex products can be decomposed and produced and assembled according to uniform standards.
Battery modules are no exception, and they are also produced and assembled on the basis of uniform standards. At present, the most popular standard in the world is the VDA standard.
Wait, what is the VDA standard?
VDA
It is the abbreviation of Verband der Automobilindustrie, meaning the German Automobile Industry Federation. They defined a series of standards for cell size, and cell modules that meet this size standard are called VDA modules.
In short, keep in mind that this is a set of industry standards. At present, this set of standards has unified the rivers and lakes.
What changes have you made to the industry with this standard?
Before the VDA unified the lake, the monomer of the power battery has a variety of specifications, as shown in the following figure:
Colorful, disorganized...
Under such conditions, the various companies in the industry chain are talking to themselves and it is difficult for them to effectively collaborate with each other and form economies of scale.
With the adoption of the VDA standard, batteries can be mass-produced and the resulting economic benefits ultimately benefit the entire industry:
First of all, from the perspective of vehicle manufacturers, under the unified standard, vehicle manufacturers can design battery packs in a targeted manner, and can compare the batteries produced by different battery manufacturers based on a unified specification and match the best battery products for the models. This is the same reason that we are familiar with the remote control battery 5, laptop 18650 battery with a standard battery size.
Secondly, from the point of view of the battery supplier, cell suppliers can concentrate their resources on introducing better cell batteries under the same conditions of the vehicle and battery structure, and they can also be iteratively upgraded very quickly. For example, the capacity of a 6-core laptop now purchased is 50% higher than that of 5 years ago. This is also the reason.
Two routes and five specifications of VDA
VDA's batteries are divided into EV and PHEV two routes, a total of five kinds of specifications. Take the ERX5 battery as an example, we are using PHEV2.
With the standard VDA cell module, isn't it time to purchase and install it?
Of course not. The vehicle manufacturers also need to carefully select among the numerous, uneven batteries, which is almost the most important watershed to witness the strength of different auto manufacturers.
To zoom in, please hold your breath.
Cell filter is like picking dishes
It is said that a pursuing chef has strict requirements on ingredients. Ono Erlang personally went to the dock every day to buy fish, rice, vinegar and soy sauce. The origin and freshness of ingredients must be carefully selected and researched in order to present the most perfect meal to customers.
Similarly, a pursuing new energy automobile manufacturer has similarly stringent screening standards for the battery module. Take the above steam as an example. In addition to the use of industry-leading suppliers, SAIC will also strictly screen the modules provided by suppliers.
The indicators tested by SAIC batteries include OCV testing, self-discharge, internal resistance, and capacity sampling. Engineers conduct stringent checks and controls.
Why should such a strict screening be carried out?
We all know that "short board principle" - that part of the battery in the short position determines the combat effectiveness of the entire battery. A small part of the battery with insufficient capacity will, after a long period of unreasonable use, greatly accelerate the aging of the battery. It can be said that at the beginning of the 1% capacity difference, as the use of time increases, the difference will continue to increase significantly.
After introducing a rigorous screening process, SAIC will first perform consistent screening and matching according to the time of shipment of the module to ensure that the same batch of modules are combined to minimize differences.
For batteries with large individual differences from the module, SAIC will continue screening and testing to ensure the consistency of the batteries in the entire battery.
Therefore, when the battery manufacturer's quality level fluctuates, SAMSUNG's own brand of electric core module can always adhere to the quality level and ensure the consistency of the product as a whole, which is also an important source of confidence for the “8-year 200,000-km†attenuated warranty commitment. .
Iron bones also have soft layers of protection to highlight safety
After strict selection and selection of good batteries, is it all right?
This is not enough. For a power battery, it is not just a simple matter to put a battery into it. How to protect the batteries is also a very challenging task.
SAIC has a complete battery safety protection mechanism and creates a “four-fold protection†for battery safety to ensure the safe use of car owners.
Protection 1: protection of the lower aluminum plate, stone-resistant design
When the car is running, the position of the vehicle's bottom and wheel fenders are easily impacted and washed by mud sand, gravel, and sewage. In such cases, the general paint is easily damaged, so that it is easy to lose the protective capabilities, so that these parts quickly corroded.
As the battery system is directly arranged under the vehicle, in order to prevent the external force from damaging the aluminum alloy housing, the anti-rock car primer used by SAIC has the characteristics of sand impact resistance and corrosion resistance.
Take Roewe ERX5 as an example, its principle of anti-stone attack is as follows:
Protection 2: Body side and front frame
The side frame and the front frame of the vehicle are mainly made of aluminum alloy. This material has a low density (density of 2.7g/cm3), high strength, good thermal conductivity, excellent processability, corrosion resistance, mature technology, and recycling. Higher rates of a series of features and competitive advantages.
The use of 6-series aluminum profiles has good plasticity and excellent corrosion resistance, in particular no stress corrosion cracking tendency, and good welding performance.
Protection 3: Combination of lightweight design and structural reinforcement
By strengthening the structural design, especially the design of the internal structure, the battery box can withstand the weight of the battery module, and also matches the mechanical requirements of the vehicle.
In terms of structural design, SAIC considers the modal performance of the lower case. By monitoring the modal frequencies and mode shapes, the dynamic stiffness characteristics of the structure can be determined. With complete design simulation and experimentation, it fully meets the vibration requirements of the battery system and forms a perfect combination with the entire vehicle system.
Protection 4: Combination of battery system and vehicle system
Through the vehicle-level simulation design, the collision safety of the vehicle and the battery system is guaranteed when the vehicle encounters an emergency and an accident.
Thanks to the above comprehensive security protection design, the battery of SAIC New Energy Automobile can finally be kept safe and secure in all kinds of harsh scenarios.
Let's take a look at the effect of a real crash test:
For the battery of an electric car, there are more parts and components around the car body, and it is very difficult to protect the side of the car body. In the absence of a separate side collision law in China, the Roewe ERX5 has challenged the most stringent European standard side impact tests.
(As can be seen from the collision diagram, the outer frame of the battery remains intact under great acceleration)
Indoor Outdoor Fiber Optic Cable,Indoor Outdoor Fiber,Indoor Fiber Cable,Indoor Fiber Optic Cable Types
Zhejiang Wanma Tianyi Communication Wire & Cable Co., Ltd. , https://www.zjwmty.com