Proposal to amend para. 2.2.2.4. to include electric regenerative braking system and electric propulsion system, amend para. 2.21. to define Electric Regenerative Braking (ERB), add para. 2.56. to define e-trailer, amend para. 5.2.2.7. regarding braking surface connection and electrical regenerative braking system disconnection, insert para. 5.2.2.26. establishing special requirements for e-trailers and trailers equipped with ERB of Category O₃ or O₄, insert Annex 4 paras. 1.7.1.3., 3.1.2.6., and 3.1.3.5. requiring ERB system deactivation during brake applications and tests, insert Annex 13 para. 4.7. requiring anti-lock braking system for vehicles with ERB, and amend Annex 16 tables to include trailer regenerative system parameters, based on GRVA/2025/15.

Proposal to add definitions for “e-axle”, “e-axle trailer”, and “dynamo function” for trailers of category O₃ and O₄, amend paragraph 2.2.2.4. to reference electric regenerative braking systems and electric propulsion systems, insert new paragraphs 5.2.2.26.1. through 5.2.2.26.5. establishing special requirements for dynamo function including maximum retardation power of 20kW, wheel locking prevention at speeds above 15 km/h, and assessment according to Annex 18, insert requirements in Annex 4 to switch off electric regenerative braking systems and dynamo function during brake applications and tests, and amend Annex 19 Appendices 5 and 7 to include e-Axles in schematic diagram considerations. This document is based on GRVA/2025/15 and GRVA-21-12.

This document proposes amendments to UN Regulation 13 for trailers with dynamo function, superseding GRVA-22-26, GRVA-2025-15, and GRVA-21-12. The dynamo function converts vehicle kinetic energy into electrical energy without affecting braking system forces and is limited to trailers of category O₂, O₃, and O₄ pending further development. Maximum retardation power limits are 22 kW for O₃/O₄ trailers and 2 kW for O₂ trailers, measured using specified methods. Requirements include wheel locking prevention with braking rate not exceeding 0.04 per wheel, functional safety assessment per Annex 18, and demonstration that anti-lock and stability control systems comply when dynamo function is enabled. The dynamo function shall not be used during brake application testing. Administrative amendments update Annexes 2, 4, 5, 10, 19, 20, and 21 to reference e-axles and dynamo functions.