Meaning
A standardized thermal evaluation subjects a battery to extreme temperature fluctuations to confirm the integrity of its seals and internal connections. Completing un 38.3 test 2 is a prerequisite for the legal transport of lithium cells by air, sea, or land. The procedure involves storing the units at seventy-two degrees Celsius and then at minus forty degrees Celsius for multiple cycles.
Thermal Stress
Rapid changes in temperature cause the materials inside the cell to expand and contract at different rates. Successfully passing un 38.3 test 2 demonstrates that the battery can survive the harsh environments found in cargo holds without leaking or venting. This durability is necessary for maintaining safety throughout the global supply chain.
A failure in this stage indicates poor mechanical design or weak ultrasonic welds.
Evaluation Criteria
A battery fails the assessment if it shows signs of mass loss, leakage, or a drop in open-circuit voltage. After the cycling in un 38.3 test 2 is finished, the units are inspected for physical deformities or cracked housings. This check ensures that the internal safety features remain functional after exposure to extreme heat and cold.
Compliance Stage
This specific thermal test is the second in a series of eight evaluations. Because un 38.3 test 2 is followed by vibration tests, the batteries must be structurally sound. Achieving this certification allows a manufacturer to ship products.
