Speaking of the safety test of the car, most people understand that it is limited to collision testing. However, it is actually the component of electric vehicle power lithium batteries. Before designing, there are several different types of tests to ensure safe and reliable in actual use.
. Take BYD as an example, not only should be tested, squeezed, vibrate batteries, but even directly. Not only should I “dive”, but also “naked swim” in my country, there are many rainy days in the southern part of China, and the coastal areas will be hit by typhoon heavy rains from time to time.
. When you encounter the road surface, the power lithium battery of the electric vehicle can ensure safety when the road surface is flooded or the parking lot is flooded. BYD drops from the 30cm of 30cm into the 30cm-deep water, simulates the situation of driving the waterproof road; requires continuous driving for 30 minutes, no leakage, only qualified.
30 minutes did not open the puddle, BYD, are you sure it is not to enter the lake? However, this is not enough, BYD will throw the battery into the salt water, simulate the whole vehicle, soak the water; ask for two hours in the water below the water, the battery can not enter the water. Do you think this level is it? BYD also peels all the charges to 90% of the battery package, turn on the switch, and then throws it into the salt water; requires “protective clothing, directly relying on the body quality hard”, even soaking ends Within one day, electric sparks (arc) can not be displayed, and they can not get fire; ensure that even if the sealing protection of the battery is damaged by the crash, the battery pack is in water, and the driving personnel can also ensure the safety of the driving personnel..
“The opening of the brain hole”, the current market, the electric vehicle power lithium battery is the cause of the electric vehicle, and many of them are caused by the charging exceeding the battery voltage limit.. The safety test of this overcharge problem should be, the difficulty of the lithium-ion battery is relatively large, and BYD also sets the extreme cases of the cerebral holes, adding higher than the threshold: the accuracy of the battery voltage monitoring and collecting signals The frequency, the synchronization is not high enough, can immediately discover immediately when the voltage is abnormal; can not be intelligently differential, different levels of risk, automatically take the corresponding measures, such as alarm, limit current, control relay disconnection circuit, etc.
, block over charge If all monitoring, all of the electronic systems have failed, overcharge has occurred, and there is no other method that does not rely on the electronic system, can abort the charge, thereby reducing the loss, to ensure personal safety? BYD’s original patented security means, pure mechanical protective device CID is the final resort to the last extreme problem. It is driven by the internal pressure of the battery in the over-filled, do not cut the circuit when the electronic signal can be intermittent, ensuring that the battery will not fire because of overtime..
Let the smoke walk the people to prevent over-recharge test is far from the end of BYD extreme hypothesis: in case CID, or because of the fierce collision, it causes thermal out of control in the battery pack, causing a fire risk Woolen cloth? Regardless of this possibility, in case it happens, the battery’s protective measures can guarantee personal safety, minimize the loss? So the test started: from the monomer battery, to the battery module, then to the entire battery pack, all levels of fire resistance isolation, to effectively prevent the spread of sporadic thermostat, limit the damage to the small range; If the cause of a tragic collision, the cause of severe heat is out of control, and it is necessary to effectively delay the spread of heat until the battery; the exhaust passage inside the battery pack, to achieve the design goal, ensure that the battery is damaged, the gas appears Along the design well-oriented channels, it will not spray high-temperature harmful gases or even flames as other types of batteries, thereby ensuring driving by personal safety; thermal out-of-control warning systems must be able to find hazards in the first time , Rapid alarm; fire blankets between batteries and passengers must be able to escape enough time. It’s not just a moment of matter, although the voltage and temperature safety measures have passed the test, but the collision accident will not damage the battery pack structure, causing them to play properly. BYD played a collision, accelerating impact, and squeezed “combined punches”, and test more from home batteries.
. In addition to the performance of battery safety in front, offset, behind, side collision test, BYD also specifically targets the particularity of electric vehicles, added more difficult for professional testing standards such as Chinese inquiry. , Inspection, inspection of double-layer high-strength aluminum alloy battery trays, cellular structures to strengthen the tray border, etc.
Can afford battery safety. In addition to the collision test of the vehicle, BYD also impacts the battery pack with nearly double the international standard, to simulate the emergency stop or urgent acceleration of vehicles in collision accidents, requiring the internal structure of the battery to be intact under impact. The color is not enough, in order to verify that the collision accident occurs, the vehicle is strongly sustained to press the safety, BYD uses 100KN, equivalent to 10 tons of heavy-riding strength to extrud the battery pack, asks the battery The bag will not live in fire, and the person can escape enough time.
. Continue to open 300,000 kilometers bad way? In addition to the safety of the special case, the design, production and assembly of electric vehicle power lithium batteries should also consider the safety of the full life cycle..
For example, BYD continues in the vertical, horizontal and vertical random vibration test of the battery pack in accordance with the vibration frequency of the vehicle on real bad road, and during the period, the charging and discharge cycle is required, and the driving and discharge cycle is simulated from 300,000 kilometers. In the state, the test battery pack leads to the safety risks of the bumps, the safety risks such as components, the housing rupture, etc..
Directly use fire! Even if you have a power lithium battery through all the above tests, BYD still has a more severe test arrangement.. For example, the flame throwing the refining of 500 ¡ã C is burned for 70 seconds.
If there is a flame, if there is a flame, it is necessary to go out within two minutes after the fire source is removed.. For example, let the battery pack at a low temperature of -40 ¡ã C for 8 hours, then increase the ambient temperature to 85 ¡ã C within 30 minutes, then take 8 hours, cycle 5 times, require the battery without leakage, fire phenomenon.
As a mature BYD battery, it is not only possible to express it, the charging is fast, the power is strong, and it is necessary to dive, can fight fire, hit, anti-shake …
Do you feel that BYD’s battery is too difficult? But don’t pass the 1998th difficult test how to be a Buddha guarantee the safety of consumers? So there is only a happy battery safety engineer who wishs B.