Proposal to replace the heating rate requirement of ≥15 °C/s with ≥10 °C/s in Annex 9K Appendix 1 Table 1, and insert new Annex 9K Appendix 1bis setting out the Thermal Runaway Trigger Method with a Localized Rapid Heater within the cell casing. The new appendix specifies preparation of the tested-device, selection guide for the heater element with target parameters including material, thickness, area, heating rate, maximum temperature and control method, test procedures for vehicle-based testing, and test procedures for component-based testing.