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Same type determination

Chapter 9 is new in the 2025 edition. Clause 9.1 defines "same type" as all 17 conditions met simultaneously. If any one condition is not met, the modified pack/system either needs the supplemental tests in Table 7 or, for some changes, a full re-test.

The 17 conditions (9.1)

A battery pack or system is considered to be of the same type if it meets all of the following conditions:

  1. Cell and module identity. The battery cell and module specifications, model, and manufacturing company are the same.
  2. Casing. The casing material (metal/non-metal), external shape, and mechanical structure are the same.
  3. Mounting. The installation method is the same, the number of mounting points is the same or increased, the mounting point positions are the same, and the mounting point structural design is the same.
  4. Energy. The energy of the batteries inside the battery pack is the same or reduced by no more than 20 %.
  5. Cell/module fixation. The method of fixing and installing the battery cells and modules is the same.
  6. Thermal management — primary. The layout, working method, and cooling medium of the battery pack's thermal management system are the same.
  7. Thermal management — flow path and interface. The flow path arrangement of the battery pack's thermal management system is the same, and the specifications and model of the external cooling medium interface of the battery pack are the same.
  8. Insulation material. The insulation material is the same.
  9. Series count. The number of series-connected battery cells and modules is the same, or the number is reduced but the internal structure remains unchanged.
  10. BMS. The hardware specifications, model, and manufacturer of the BMS are the same; the software version is the same (unless it does not affect the safety of the power battery); and the protection parameters and thresholds in the control software are the same (e.g., same thermal protection strategy, same thermal alarm strategy, same thermal event alarm signal). The BMS manufacturer is the same.
  11. Electrical components. The rated voltage and current load capabilities of the electrical components are not reduced.
  12. HV circuits. The number of high-voltage circuits inside the battery pack is the same or reduced.
  13. Switches and connectors. The number, specifications, and arrangement of maintenance switches, high/low-voltage connectors are the same.
  14. Pressure relief. The number, specifications, and arrangement of pressure relief devices are the same.
  15. Length, width, height. The length and width dimensions of the battery pack have a difference from the nominal value within ± 1 %, and the height dimension has a difference from the nominal value within ± 5 %.
  16. Mass. The mass of the battery pack is between 90 % and 103 % of the nominal value.
  17. Mirror symmetry. For battery packs mounted symmetrically on the vehicle, the external structure of the battery pack and the arrangement of the battery modules satisfy the mirror symmetry.

Source: clause 9.1 (PDF page 28).

Non-obvious conditions worth flagging

Engineering note (non-normative):

  • Condition 4 (energy ≤ 20 % reduction): the standard allows a reduction in energy without breaking same-type. An increase in energy breaks same-type — even by 1 %.
  • Condition 9 (series count): likewise, fewer series cells is allowed (with internal structure unchanged); more is not.
  • Condition 10 (BMS software): "unless it does not affect the safety of the power battery" is the only ambiguity in the chapter. In practice, regulators read this narrowly — any change to thresholds, alarm strategy, or protection logic breaks same-type regardless of the version string.
  • Condition 15 (dimensions): the L and W tolerance (± 1 %) is much tighter than the H tolerance (± 5 %). For a 1.8 m pack, this means ± 18 mm in L/W vs ± 90 mm in H. Pack-floor redesigns that gain ground clearance often pass; pack-footprint changes usually do not.
  • Condition 16 (mass): the asymmetric window (90 % – 103 %) tolerates losing weight more than gaining it. Adding a heat-spreader plate that pushes mass past 103 % nominal breaks same-type.

What "not same type" triggers

If one or more conditions in 9.1 are not met, clause 9.2 governs: the manufacturer may run only the supplemental tests in Table 7 for the conditions that failed. Some condition failures (notably condition 1 — cell/module change) trigger all test items per Table 7 row 1.

Source

Clause 9.1 (PDF page 28).