Pack-level test preparation under UN 38.3 and IEC 62619

UN 38.3 is the section of the UN Manual of Tests and Criteria dealing with the TRANSPORT of lithium cells and batteries. It asks a single question: does this battery safely withstand the stresses of transport?

IEC 62619, meanwhile, addresses a different question: the safety requirements of lithium-ion cells, modules and packs in stationary applications. One covers shipping, the other covers use.

In practice this means: a battery without a UN 38.3 report cannot be shipped, and one without IEC 62619 conformity is not accepted in the target application. Neither substitutes for the other.

The tests under UN 38.3 are commonly called T1–T8 and applied in a defined ORDER. The series comprises altitude simulation, thermal cycling, vibration, shock, external short circuit, crush or impact, overcharge and forced discharge.

The order is not arbitrary: each test is applied to the state left by the previous one. Swapping samples between tests or breaking the sequence therefore invalidates the report.

The most commonly confused point is the difference between cell and pack. Tests T6 (impact/crush) and T8 (forced discharge) are required for lithium-ion cells; they are not required for packs.

This is direct planning information for pack makers: no sample or time need be set aside for these two tests at pack level. But the cell inside the pack must have its own UN 38.3 report — the pack report does not replace the cell report.

The supply-chain consequence: if cells are purchased, the cell's report must be obtained from the supplier and the pack report built on it. Starting pack testing without the cell report is wasted time.

Sample count, test sequence and the configuration in which the pack enters testing (management circuit connected, enclosure fitted or not) must be set in advance. If the configuration changes later, the test is repeated.

Another point is the limit at which a design change affects the report: changing the cell type, enclosure or protection circuit generally requires a new assessment. Without a change-management process, the report silently becomes outdated.

Test conditions, durations and acceptance criteria are in the standard's text; we determine together at the proposal stage which sequence applies to your scope.

These two requirements are often mentioned together but answer different questions and neither replaces the other. Transport requirements ask whether the battery is safe during TRANSPORT: safe behaviour under altitude, thermal, vibration, shock, short-circuit and overcharge conditions.

The product safety standard asks whether the battery is safe during USE: the function of protection circuits, cell balancing, heat spread and behaviour in fault conditions.

A battery that has passed transport testing may therefore not have been assessed for product safety, and the reverse is also true. Transport evidence is mandatory for a shipment but not sufficient for placing on the market.

Pack-level tests are destructive and consume the sample; also, since pack production comes after cell supply, the test schedule gets squeezed to the very end of product development.

The approach that eases this squeeze is a design review before the pack design is finalised: protection-circuit architecture, venting paths, cell layout and connection arrangement are assessed at that stage.

Sample count is a critical planning item: the test series consumes multiple samples, and without a spare, a failure means replanning the programme from scratch.

Shipping lithium batteries is subject to dangerous goods rules, and the evidence is that the test summary document be present in the shipping file. Its form and content are defined.

Packaging, marking and labelling are separate requirements: whether it is a cell or a pack, and whether shipped with equipment or alone, changes the packaging class and label.

There are additional restrictions for air and sea transport; the same battery may be accepted under one transport mode while subject to extra conditions under another. The shipping plan is therefore built together with the transport mode.