Did you know that lithium batteries need to certified to UN38.3 for transportation?
In today’s society, rechargeable lithium batteries are becoming more and more popular in our lives and the application fields are also expanding, such as mobility vehicles (RVs, Caravan, Motorhome, Camper, Marine, Boat, Golf Carts, E-scooters, E-Bike, etc.), solar energy storage system (solar power system, home energy storage system, UPS, etc.), electronic products (mobile phones, laptops, cameras, remote control toys, etc.), so the transportation demand for lithium batteries or goods containing lithium batteries are also increasing.
The United Nations has specially formulated standards for the transportation of dangerous goods (refer to Clause 38.3 of Part 3 of the “United Nations Manual of Dangerous Goods Transport Tests and Standards”) to ensure transportation safety and meet customer demand for dangerous goods transportation.
The United Nations has specially formulated standards (refer to Clause 38.3 of Part 3 of the “United Nations Manual of Dangerous Goods Transport Tests and Standards”) to ensure transportation safety of dangerous goods and meet customer demand.
The Department of Transportation and other international regulatory parties require lithium batteries or goods containing lithium batteries certified to UN38.3 before transport.
Lithium batteries must undergo eight rigorous tests conducted by an accredited independent testing laboratory to receive UN38.3 certification.
In this blog, we will explain which eight tests the battery will perform and how to perform the tests.
Altitude Simulation, which simulates low pressure (high altitude) transportation.
Lithium batteries should be stored at a pressure below 11.6kPa for at least 6 hours at ambient temperature (20±5°C). The battery should have no leakage, no venting, no disassembly, no rupture, no fire, and the open-circuit voltage of the battery should not be less than 90% of the voltage before this test.
Thermal Test, which evaluates the sealing integrity and internal electrical connections of the battery through rapid and extreme temperature changes.
The lithium batteries are to be stored at high temperature 72±2℃ for at least 6 hours, then stored at low temperature -40±2℃ for at least 6 hours. The maximum interval time for switching between two extreme temperature conditions should be less than 30 minutes. This procedure is to be repeated 10 times, after which the tested batteries are to be stored for 24 hours at ambient temperature (20±5℃). For large batteries, the duration of exposure to the extremes should be at least 12 hours. The battery should have no leakage, no venting, no disassembly, no rupture, no fire, and the open-circuit voltage of the battery should not be less than 90% of the voltage before this test.
Vibration Test, which simulates the vibration generated during transportation.
Lithium batteries are firmly secured to the platform of the vibration machine without distorting the cells in such a manner as to faithfully transmit the vibration. The vibration should be a sinusoidal waveform with a logarithmic sweep between 7Hz and 200Hz, and back to 7Hz traversed in 15 minutes. This cycle should be repeated 12 times for a total of 3 hours for each of the three mutually perpendicular mounting positions of the battery. One of the directions of vibration must be perpendicular to the terminal face. The battery should have no leakage, no venting, no disassembly, no rupture, no fire, and the open-circuit voltage of the battery should not be less than 90% of the voltage before this test.
Shock Test, which assesses cells and battery’s ability to withstand cumulative physical shock during transportation.
Lithium batteries should be secured to the testing machine by means of a rigid mount which will support all mounting surfaces of each test battery. Each cell or battery shall be subjected to a half-sine shock of peak acceleration of 150gn and pulse duration of 6 ms. For larger cell or battery, the peak acceleration shall be 50gn and pulse duration of 11 ms. Each cell or battery shall be subject to three shocks in the positive direction and three shocks in the negative direction in each of three mutually perpendicular mounting positions of the cell or battery for a total of 18 shocks. The battery should have no leakage, no venting, no disassembly, no rupture, no fire, and the open-circuit voltage of the battery should not be less than 90% of the voltage before this test.
External Short Circuit, which assesses the battery’s ability to withstand prolonged external short circuit conditions.
Lithium batteries should be heated for a period of time necessary to reach a homogeneous stabilized temperature of 57±4℃, measure on the external case. Then the batteries should be subjected to a short circuit condition with a total external resistance of less than 0.1Ω. This short circuit lasts at least 1 hour after the cell or battery external case temperature returns to 57±4℃. Within 6 hours after the test is completed, there should be no rupture, no disassembly, no fire, etc., and the batteries external temperature should not exceed 170℃.
Impact / Crush Test, which simulates a battery’s ability to withstand mechanical abuse that could create an internal short circuit.
The sample cell or component cell is to be placed on a flat smooth surface. A type 316 stainless steel bar with a diameter of 15.8±0.1mm and length of 6cm to be placed across the center of the sample cell. Drop a 9.1±0.1kg weight from a height of 61±2.5cm to the intersection of the steel bar and the sample. Use a vertical track or pipe that has almost no friction and has minimal resistance to the falling weight to guide the drop hammer to fall at 90 degrees along the horizontal support surface. Each cell should be subjected to a single impact. Within 6 hours after the test is completed, there should be no rupture, no disassembly, no fire, etc., and the cells and batteries external temperature should not exceed 170℃.
Overcharge Test, which is to evaluate the battery’s ability to withstand overcharge conditions.
The charge current should be twice the manufacturer’s recommended maximum continuous charge current. The charging cut-off voltage is divided into the following two cases:
- When the manufacture’s recommended charge voltage is not more than 18V, the charge cut-off voltage of the test should be 2 times the maximum charging voltage or 22V, whichever is less;
- When the manufacturer’s recommended charge voltage is more than 18V, the charge cut-off voltage of the test should be 1.2 times the maximum charging voltage.
Tests are to be conducted at ambient temperature, the duration of the test should be 24 hours. After the test, there should be no disassembly and no fire within 7 days.
Forced Discharge Test, which tests the battery’s ability to withstand its stated maximum discharge rating.
Each cell should be forced discharged at ambient temperature by connecting it in series with a 12VDC power supply at an initial current equal to the maximum discharge current specified by the manufacturer. The specified discharge current is to be obtained by connecting a resistive load of the appropriate size and rating in series with the test cell. Each cell should be forced discharged for a time interval (in hours) equal to its rated capacity divided by the initial test current (in ampere). After the test, there should be no disassembly and no fire within 7 days.
If the lithium battery is not installed in the device, and each package contains more than 24 battery cells or 12 batteries, an additional 1.2m drop test is required.
1.2m Drop Test
The package must be able to withstand the drop test of 1.2m in any orientation without damaging the battery or cell in the package, without changing the position of the battery in the package, so that the battery and the battery contact each other, and no battery leaks from the package.
The responsibility for ensuring that the battery complies with the United Nations standards rests with the seller. Unfortunately, some products on the market do not meet the standards. The life of lithium batteries may be as long as 15 years or longer, depending on how often it is discharged. UN38.3 is an extremely important safeguard for your customers, and UN38.3 certification should be a primary consideration in your lithium battery purchase.
Polinovel is committed to providing safe and environmentally sustainable lithium battery products. We have invested in UN38.3 certification in our products to ensure that we meet the industry’s quality and safety standards.