What is the UN38.3 Test
UN38.3 is a mandatory safety standard for lithium batteries during transport, as specified by the United Nations. This regulation ensures batteries can withstand conditions such as pressure, temperature, shock, and impact without leakage, fire, or explosion.
The Manual of Tests and Criteria contains criteria, test methods and procedures to be used for classification of dangerous goods according to the provisions of the “United Nations Recommendations on the Transport of Dangerous Goods, Model Regulations”
At the time of writing, the document is at Revision 8 which was released in November 2023. We are interested primarily in Part III which covers Class 9 Dangerous Goods, of which Lithium metal and Lithium Ion batteries are a part. Specifically Para 38.3 details the tests that must be passed by battery cells and manufactured batteries to ensure they are as safe as possible for transportation around the world, by road, sea or air.
The document lists 8 different tests (T.1 to T.8) which apply to different batteries and test subjects. For example, Lithium Ion batteries should be tested to T.1 through T.5 and be constructed with battery cells that have previously passed the UN 38.3 cell level tests (which all reputable cell manufacturers ensure is the case). Additionally, if the battery incorporates the protection against over-charging (i.e. a battery management system [BMS]), T.7 test applies. Generally 8 samples of the battery under test are required for test T.1-T.5. Test T.7 can be performed on the same samples, or on a different set of 8 sample batteries (if the original samples are showing signs of deterioration from the initial five tests.
At the end of the (successful) test, the batteries get a report detailing the tests and the results obtained together with a summary certificate which declares the tests have been done and passed. As the tests are design level tests, all batteries to the same design are covered by the certificate. This certificate is required by couriers and carriers for transportation of the batteries.
This is a simplified explanation: different batteries have different requirements depending on the type, weight and dimensions.
Test details
Comprehensive UN38.3 Test Suite Includes:
Test Description
T.1 – Altitude Simulation Ensures battery safety at air transport pressure levels.
T.2 – Thermal Test Cycles between high and low temperatures to test battery integrity.
T.3 – Vibration Simulates transport vibration to evaluate physical durability.
T.4 – Shock Tests resistance to sudden impacts.
T.5 – External Short Circuit Ensures protection against short circuits.
T.6 – Impact / Crush Verifies safety in case of mechanical impact.
T.7 – Overcharge Applies to rechargeable batteries; tests overcharge protection.
T.8 – Forced Discharge Applies to primary batteries; tests if incorrectly charged