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Testing with the vehicle body

For modern CTB / CTC architectures the pack enclosure is the body frame. The standard recognises this in three places: a general allowance in 6.1.3, a compression-specific rule in 8.2.4.1, and an external-fire rule in 8.2.7.1.1.

General allowance (6.1.3)

For battery packs or systems that are enclosed by a body frame and constitute the battery pack enclosure, testing can be performed with the enclosure or body frame.

The "body frame" is defined in 3.20:

The spatial frame structure that ensures the strength and rigidity of the vehicle body. [Source: GB/T 4780—2020, 4.4.3]

Source: clauses 6.1.3, 3.20 (PDF pages 13, 11).

Compression test rule (8.2.4.1)

The test object is a battery pack or system. For battery packs or systems installed inside the vehicle body frame, it is allowed to conduct the test with the body structure components included.

The compression stop condition is then modified:

Stop compression when the compressive force reaches 100 kN or when the deformation in the compression direction reaches 30 % of the overall size in the compression direction. For cases where compression is performed with the body structure components, stop when the compressive force reaches 100 kN.

Configuration Compression stop condition
Pack / system alone 100 kN or 30 % deformation, whichever first
Pack with body structure 100 kN only (no 30 % deformation cutoff)

Source: clauses 8.2.4.1, 8.2.4.2 e (PDF pages 20–21). See pack/system compression.

External fire rule (8.2.7.1.1)

The test object is a battery pack or system. The body structure that protects the battery pack or system may also be included in the fire test.

Source: clause 8.2.7.1.1 (PDF page 24). See external fire.

Why the three clauses differ

Engineering note (non-normative):

  • 6.1.3 is the umbrella permission — if the body frame is the pack enclosure, the body frame can be the test object.
  • 8.2.4.1 is more specific: the body can be included even when it is outside the pack enclosure (i.e., installed-in-frame architectures, not just CTB/CTC). The trade-off is that the deformation-based stop condition is removed, because deformation of the body is no longer a meaningful proxy for cell loading — the test stops at the force ceiling.
  • 8.2.7.1.1 explicitly opts in the protective body structure for the fire test. Manufacturers usually want this — the body acts as a heat shield.

Bottom impact (8.2.16) does not have an analogous "include body structure" clause; the test method specifies the impactor parameters but not the test object scope. In practice, vehicle-level tests on whole vehicles satisfy the body-structure inclusion implicitly.

Cross-reference

Source

Clauses 6.1.3, 3.20, 8.2.4.1, 8.2.7.1.1 (PDF pages 11, 13, 20–21, 24).