UN 38.3 Transport Testing Solvent Leakage Requirements
UN 38.3 limits lithium cell solvent leakage during transport through strict mass loss thresholds and zero visual electrolyte loss criteria across T.1-T.8 tests.
T.4 Mechanical Shock
Meaning
Safety certification test that subjects lithium batteries to simulated heavy impacts and sudden deceleration evaluates their structural integrity during transit and handling. This test, designated as T.4 Mechanical Shock, is a mandatory part of the United Nations transport testing suite required for the legal shipping of lithium-ion products. It ensures that the cells and pack assemblies can survive severe shocks without physical damage, venting, or thermal runaway.
Test Procedure
The test protocol subjects the test samples to a half-sine shock wave of peak acceleration and pulse duration that varies depending on cell size. Small cells are exposed to a high peak acceleration of one hundred and fifty times the force of gravity over six milliseconds. Large battery packs are subjected to fifty times gravity over eleven milliseconds, and these forces must be applied in both positive and negative directions across three perpendicular axes.
Sourcing Requirements
Sourcing contracts for automotive and industrial battery packs mandate that all suppliers must provide certificates of compliance with this transport test. Battery cells cannot be shipped to the assembly plant or the customer without passing this certification, making it a gating item for the procurement timeline. This requirement reduces the risk of shipping delays and ensures that all incoming goods are legal to transport.
Transport Simulation
Crash protection validation requires different testing methodologies that use much higher, destructive forces than the deceleration simulated during these transit checks. Compliance with this transport standard does not guarantee crash safety under extreme automotive test conditions.