Model 3 Explosion: Electric Automotive Major Technology "Defect" is revealed!

　　Author ：Iflowpower – Portable Power Station Supplier

Lead: About electric car users, we hope that everyone will pay attention to electric car chassis bumps, don't be nothing, although there is no national standard, but we have to be a tester, responsible for your life. Editor: Little flower reporter: Dazhao produced: WXID-Dianxiaoer01) Evening, a Tesla Model3 spontaneously in the Shanghai, Shanghai, and then several serious explosions. There is a user in Weibo @ 我们, I hope we analyze a wave.

Combined with model3, according to our previous interview with the related battery engineer, and in the discussion of the electric potential fan group, we believe: "This MODEL3 self-ignition explosion, exposes a major technical defect that an electric car has been unresolved. - Battery pack without bottom shell collision warning. "In other words, whether it is Tesla Model3, or any other electric car, as long as the battery pack touches, and triggered the short circuit in the core, the car can't prevent spontaneous combustion.

And, this is the pain point for the industry, there is currently no effective technical means to avoid. In addition, it is to be explained that the battery cover housing collision warning is not a thermal out-of-control warning, the difference is: as long as the thermal out of control, electric cars will warmed; and the battery pack bottom shell is seriously collided, but will not warn the heat loss. 1, "3 cars", the reason that triggered the self-ignition event.

"Note: This is Tesla initial judgment, non-final notification. If you still have memories, such an accident has two. In the past 8 years, a Xiaopeng G3 suddenly splamed in the street.

After the accident, Xiaopeng officially lifted the car, and found that there was a significant serious bump marks at the bottom of the battery case, causing the battery to be seriously damaged, and judging this is the reason for the accident. Look forward. In April 2019, Xi'an Wei came to the service center, an ES8 spontaneous combustion, this is also the first spontaneous combustion accident occurred in Wei Es8.

After that, the official announcement of the official announcement, "The vehicle chassis has suffered severe impact, the battery pack shell and the cooling plate are deformed, the internal structure of the battery pack is squeezed after a period of time and short circuit. "From the time of the owner of the car, the chassis will continue to travel after collision. This is also aware of the above, it can also be seen: short circuit after a period of time.

2, the hot out-of-control warning no matter in GB38031-2020, it is still in the older GB / T31345-2015, that is, "electric vehicle power storage battery safety requirements", clearly defined 5 minutes of thermal out of control, if not, that is unqualified product. As for the above three cars, there is no warning at the time, from the following subsequent feedback: no. Then why didn't you send a warning, is these three cars unqualified? For the market product, these three cars are not bad, they can't seem to say.

So, or the user is lying, or the user didn't pay attention to the warning, or it is really unqualified. In fact, this problem is nothing to discuss, it is very simple, as long as the monitoring background, I know that there is no warning at the time, these manufacturers are understanding, this is also the barrier and user consultation. 3, the controversy of the industrial collision collision these cases truly reflect, why don't you send a warning to the user at the time? If you have a warning in advance, the owner's parking is taken to repair, can you free from a self-ignition? However, the fact is that in the current battery pack design, there is no such as the bottom shell collision, on the one hand, everyone feels unnecessary, and then the national standard has no hard requirements.

In GB38031-2020, 8.2.3 Battery Pack Analog Collision Test, the collision test direction is the X-axis direction of the car travel, and the other perpendicular to the horizontal direction of the traveling direction.

As for the Z-axis direction perpendicular to the ground, it is no collision test. So the problem will appear, why don't you set the bottom case collision warning? There are two points in this, one, one, the hardness of the battery pack is sufficient, enough to resist general collision; two, if the collision is particularly serious, causing thermal failure of the battery bag, or the coolant leak, will issue alarm. The above three vehicles are self-in, the reason is that the degree of collision is between the "intermediate morphism" between the general collisions and the severe collisions, that is, the bottom case is deformed, but the battery is extruded, but there is no short circuit out of control, coolant There is no leak to cause insulation.

Ignore the middle-morphism of the collision, or whether the collision affects the normal operation of the battery, it is the key to the problem, which involves the squeezing test of the battery. 4, the source of sin - the electrical core extrusion carefully analyzes the process of the above three cases, first of all, the battery pack undercar is seriously collisted, followed by thermal out of control spontaneous combustion. So why didn't you send a warning at the time? Because when the bottom shell is deformed, the battery is squeezed, the battery is still unfained, the car continues, and the battery cell is short-circuited after discharge.

From the case of ES8, the car was collided at the bottom shell. After the battery was squeezed, it was carried out normally, and it was charged, and the fire is located next to the charging pile. Xiaopeng G3 and this Tesla Model3, also after the battery is squeezed, the car continues to travel, the battery is continuously discharged, the inside short circuit, the heat is out of control.

Therefore, the cell is squeezed, becoming the key to these three accidents. Does the national standard do not have a cell extrusion test? Yes, not only the battery, but the battery pack extrusion test has. 5.

The defects in the national standard cell test are in GB38031-2020, and there is a squeezed test for the battery and battery packs. The extrusion test of the battery pack is the X-axis and Y-axis, and there is also no Z-axis. However, the most critical place is that the national standard test is completed under the battery cell and the battery pack, and the actual situation is under "dynamic situation".

The so-called static working condition is a moving battery change after the battery extrusion test, and the dynamic situation is the battery in the car, such as the above three patients. According to the national standard, the standard for the battery is not fired after 1 hour, not self-burning, and the standard of the battery pack is not fired after 2 hours, it is not self-burning, this is the battery, battery pack. condition.

For the above 3 cars, I believe that their battery and battery packs are qualified to install the car, and the problem occurs in the bottom shell collision, and then the electrical core is extruded, and the battery core continues to discharge, will be thermal out of control That is, the dynamic situation. A person who is familiar with electric car test revealed to us, "If the national standard continues to make a charge and discharge test after extruding the battery test, then the battery will definitely. "He also said," national standard is the lowest standard, and the thermal out of control of good brands is not only 5 minutes, but not less than half an hour.

"We have confirmed from a battery factory test engineer." After the battery is finished, it will not repeat the 'power-on-discharge' re-test. "6, please pay attention to the battery pack bottom shell! Hsinwang et al.

In the US Oak Ridge National Laboratory, the battery cells have extruded test analysis, and they use low-charge square shell lithium ion batteries to study the battery in squeezing test Structure change. Hsinwang's experimental results show that the internal short circuit will occur when the battery has reached 60% or more in the extrusion direction. However, whether in GB / T31345-2015, or in GB38031-2020, the extruded variable of the battery is only 30%, and the latter has a more extrusion effort to 100KN from 200KN.

Of course, there is also a difference in high and low charge, the amount of charge of the charge is different, and the timing of the heat loss is also different. But no matter what, our new national standard is downgrade, and it is impossible to use it in static testing. This is a very low threshold.

Our people are slightly, should not be questioned again for the national standard. Friends doing time, time will prove everything. Regarding electric car users, we hope that everyone will pay attention to electric car chassis bumps, don't be nothing, although there is no national standard, but we have to be a tester, responsible for your life.

Some people in the group said that they could not drive electric cars to cross-country. He is really wit! In order to solve the hidden situation of the battery pack, it is necessary to add a view project of the battery pack appearance in the electric power supply in the accident, and cooperate with German Sigli Carbon Company to develop hardness higher carbon fiber reinforced plastics (CFRP) Battery housing. .