The drop test is usually mainly used to simulate the free drop of unpackaged/packaged products that may be subjected to during handling, and to investigate the ability of products to resist unexpected shocks. Generally, the height of the drop is based on the weight of the product and the probability of falling as a reference standard, and the falling surface should be a smooth, hard rigid surface made of concrete or steel. Refer to the relevant test standards and customer product specifications.
For different international or national standards, even if the product is under the same weight but the drop height is not the same. For hand-held products (such as mobile phones, MP3s, etc.) most of the drop height is between 1.0m-1.5m. For example, IEC recommends that hand-held products ≦2kg should meet the drop height of 1.0m and not be damaged; MIL suggests a drop height of 1.22m; Intel recommends a drop height of 1.5m for handheld products (such as mobile phones). The severity of the test depends on the height of the fall, the number of falls, and the direction of the fall.
So how are our lithium-ion battery products regulated? Now let's talk about the standards and test requirements for the drop test of lithium-ion batteries (including cells and battery packs).
1.GB/T 18287-2013 General specification for lithium-ion batteries and battery packs for mobile phones
It can be seen from the above standards that the height of the cell and battery pack used in mobile phones is not the same, and other requirements are the same.
2.GB 31241-2022 Safety requirements for lithium-ion batteries and battery packs for portable electronic products
As can be seen from the above standards, portable electronic products with lithium-ion batteries and battery pack height are the same, but for different types of lithium, such as cylindrical, square, soft bag, button battery drop surface and times will be different.
3.GB 38031-2020 Safety requirements for power batteries for electric vehicles
It can be seen from this national standard that there is no drop test requirement for lithium batteries used in electric vehicles, and there is no drop test requirement for the standard "5.2 battery pack or system safety requirements". In fact, in the previous version of the standard - "GB/T31485-2015 power battery safety requirements and test methods for electric vehicles" in the "drop test" is also required, and is 1.5 meters, the requirements are "no leakage, no fire, no explosion."
4.Iec 62133-2 (2017 edition) Secondary cells and cells (groups) containing alkaline or other non-acidic electrolytes portable sealed secondary cells, cells (groups) consisting of cells and safety requirements for applications in portable equipment - Part 2: Lithium systems
7.3.3 Free fall
a) demand
A battery or battery drop (for example, from the top of a workbench) must not cause a fire or explosion
b) Test
The free fall test is carried out at an ambient temperature of 20 ° C ±5 ° C using a battery or a battery charged to a fully charged state following the first step. In 7.1.1. Each cell or battery is dropped three times from a height of 1.0 meters onto a slab concrete floor or metal floor. Drop the cell or battery in order to get a random direction of impact. After the test, the battery or battery should be stationary for at least 1 hour, and then the appearance of the inspection.
c) Acceptance criteria
No fire, no explosion.
It can be seen from the above standards that the test conditions and methods for lithium-ion cells and battery packs are the same.
5.UL2580 Electric Vehicle Battery Safety Standard (2013 edition)
Translation: 37 drop test
37.1This test is designed to assess whether electrical energy storage components (EESA) present a hazard if accidentally dropped during installation or removal from the vehicle.
37.2After equilibration at room temperature, fall from a minimum height of 1.0 m (3.3 ft) in accordance with 18.1, striking a flat concrete surface at the location most likely to produce adverse results in a manner and height most representative of what happens during maintenance and handling/removal of EESA.
37.3Reference 37.2, if only one drop test has been performed, it must not be a flat fall. If the EESA is intended to be installed or removed horizontally, the drop of the device under test with a tilt of 10° and an impact on the edge of the component should be considered.
37.4Reference 37.2, if a drop test is a plane drop, at least one other test that is not a plane drop should be performed.
37.5Sample falls at least once.
37.6The concrete surface should be at least 76 mm (3 inches) thick and large enough to cover the equipment under test.
37.7Samples should be checked for signs of damage within 6-24 hours after falling
Temperature should be monitored during the test. If the sample is returned or kept near the environment, the insulation resistance test shall be performed in accordance with 19.2 (a).
37.8The spark ignition source outlined in Section 19 should be used to detect the presence of combustible gas concentrations in the sample immediately after descent and repeated at elevated temperatures.
37.9There must be no sign of fire or explosion. No noxious gases as defined in 6.41 shall be released. The minimum insulation resistance should be 100 Ω/V.
This UL2580 standard is mainly for electric vehicles (including electric vehicles and electric bicycles) batteries, applicable to all power cells and electric vehicle batteries. From the content of standard clauses 37.1-37.9, it can be seen that the American standard has higher requirements for drop tests and needs to consider more links.
6.UL2271 Light Electric Vehicle Battery Safety Standard (2010 edition)
翻譯:8.5 Drop test
8.5.1Fall from a height of 1.0 m (3.3 ft), striking a flat concrete surface at the location most likely to produce adverse results.
8.5.2Sample dropped at least 3 times.
8.5.3The surface of the concrete must be at least 19 mm (0.75 in) thick.
8.5.4The soft pack battery should also be tested at -20 ° C ±2 ° C (-4±3F) after at least 3 hours, and the sample should be dropped immediately in the cooling state.
8.5.5Samples should be tested 6 hours after testing. The sample should not ignite or explode. Sample housing should not be damaged and cracked.
This UL2271 standard is mainly for light electric vehicles including electric bicycles/motorcycles, balance vehicles and scooters, golf carts, etc.) battery cells and battery packs, the same conditions.
7.UN38.3,UL1642, etc., do not make clear requirements for single cell drop test. However, UN38.3 does require a drop test of 1.2 m for packages, as specified in special Provision 188 of the United Nations Model Regulations for Recommendations on the Transport of Dangerous Goods (Rev.22).
The above only refers to the domestic and European and American standards to introduce the relevant drop test requirements, the vast majority of which require "no fire, no explosion", but there are also a few standards that require "no leakage (no leakage), no fire, no explosion". Drop test as a measure of product performance indicators, the design and manufacture of products must meet the relevant standards and customer requirements. If you do product certification, refer directly to the standard test of the region or country where the product is sold; If the company does internal monitoring and continuous improvement evaluation and verification, It is recommended that when developing enterprise standards or internal control standards, we should fully consider the specific application of the product, international/national standards, peer standards, customer requirements and other factors to develop standards suitable for their own enterprises. Of course, you can also find professional certification and testing institutions to provide relevant recommendations and references. For example, some domestic standards do not require acupuncture, but some large customers abroad still have clear requirements for the battery. Well-known domestic enterprises such as BYD, Ningde Times, GAC Aean and so on have spent a lot of effort on products through acupuncture experiments. It's important to understand, The national standard is only for the most basic requirements, principles and bottom line of enterprises, so the product only meets the national standard is actually far from enough. In reality, many customers' requirements are much higher than the national standard requirements, especially large foreign customers. In order to have a strong competitiveness in the market, in addition to meeting the national standard, Our company should also continue to innovate and have hard core technology. Enterprise standards or internal control standards can be stricter than and far beyond the requirements of the national standard, and try to meet customer requirements and exceed their expectations. Only in this way can the product be invincible in the market! In addition, our sales staff and R & D technical staff in the pre-sales service docking, To fully understand customer requirements (VOC), such as some special test projects need to be optimized and improved in product design and development, materials and processes, and key breakthroughs.