Cut off
Standard prerequisites: battery cut off incorporates single short out test and module cut off. The outside short out of single battery is 10 min, and the outside cut off isn’t more noteworthy than 5 m Ω; During the short out trial of the stockpiling battery, there will be no blast or fire.
Examination and exploration of test results: during the short out trial of single power battery, the outside cut off is 2.7 m Ω, the short out current is huge, and a lot of gas is catapulted from the security valve with electrolyte. The module cut off is a few times of the single short out current (100 Ah cut off is almost 4000 A). The power battery responds all the more viciously, delivering a lot of intensity that softens the plastic shell of the power battery, causing serious distortion. Burning frequently happens during the time spent module cut off, because of a few reasons: the protection material of the metal interfacing piece between the single batteries isn’t fire sufficiently resistant, consuming happens at high temperatures, touching off the power battery;
The protection material of the plastic shell of the battery has lacking fire resistant grade, which consumes at high temperature and lights the power battery: the wellbeing valve is set too firmly, and a lot of intensity produced by the battery during short out can’t be delivered in that frame of mind, in warm out of control, prompting blast, shoot and different peculiarities of the battery: the electrolyte is a combustible fluid, which is not difficult to consume at high temperature, and fitting fire resistant is added, It can work on the security of force battery (the exhibition of force battery with fire resistant will be diminished), and the option of fire resistant ought to be proper. In the event that the battery actually experiences fire and blast after the above issues are killed in the test, top to bottom examination will be led on the well established causes like electrolyte, terminal materials and equation.
Existing issues and ideas: It is prescribed to direct equipment over-current assurance (PTC) for each single power battery (chiefly round and hollow little limit battery): in the event of short out, the current is too enormous, the circuit will be consequently cut off, and after the battery temperature recuperates, the circuit will be naturally associated with safeguard the battery. For overlaid power batteries, adding wires between a few batteries is suggested.
As of now, the power battery security test things determined in the worldwide obligatory guidelines are standard test things. Because of the nonstop advancement of force battery innovation, more inside and out examination and investigation are required. Accordingly, a few undertakings set forward higher test necessities for their items in the creation cycle, like submersion, fire, shooting, vibration and other Research and development tests.
Water inundation test
Test strategy: put the completely energized battery module into salt water for release test (the profundity of water, convergence of salt water and release momentum will be proposed by the endeavor). During the test, there will be no blast or fire.
Investigation of experimental outcomes: This test thing predominantly reenacts what is happening of electric vehicle swimming or power battery overflowed because of catastrophic events of flood. As the battery is submerged in water, higher prerequisites are advanced for the security level of the battery. On the off chance that the assurance of the battery is poor, water entering the battery will cause short out of the battery: the security valve and terminal are powerless parts. When the salt water is submerged in the battery, causing a short out, the battery will deliver a ton of intensity and gas, which will cause the salt water to produce a ton of air pockets or even bubble.
Fire test
Test strategy: put a completely energized battery module into a fire and consume it (fire power and consuming time will be proposed by the venture). During the test, there will be no blast or fire.
Examination of experimental outcomes This test thing mostly mimics the ignition of the vehicle because of unusual circumstances, and the power battery is in the fire. In the event that the power battery detonates or bursts into flames, it will additionally strengthen the ignition of the vehicle, representing a more prominent danger to the wellbeing of travelers. In the test, because of the great outer temperature of the power battery, higher prerequisites are advanced for the fire retardancy of the power battery shell, and furthermore for the fire retardancy of the arrangement.
Shooting test
Test strategy: place the completely energized battery module in an upward direction for release test, and fire with a weapon toward the path opposite to the cathode plate (the release current, discharging position and shooting times will be given by the undertaking). During the test, there will be no blast or fire.
Examination of experimental outcomes: This test thing mostly reenacts that the slug raises a ruckus around town battery of the electric vehicle moving under unusual conditions, for example, psychological militant assaults. Projectile taking shots at the power battery will cause inner short out of the battery, delivering a ton of smoke and intensity. In the event that the intensity isn’t delivered in time, it could be joined by ignition, blast and different peculiarities.
Vibration test
Test technique: fix the completely energized battery module on the vibration table according to the genuine vehicle status for release (vibration conditions and release current will be given by the venture). During the test, there will be no blast or fire.
Investigation of experimental outcomes: This test thing fundamentally reenacts the vibration created by vehicles going on various streets. Under the state of vibration, the dynamic substances on the battery shaft piece might tumble off, and the battery terminal, spot welding contact, haul, outer wiring, patch joint, and so on may dampen and tumble off, in this way causing outside or inner short out of the battery.
