The Informal Working Group on EV/HFCV Retrofit Systems held its ninth meeting on 11th June 2026. The group discussed electrical safety, cybersecurity, braking, EMC, power determination, battery range, and the overall approval concept for retrofit systems. Discussions covered UN Regulations 100, 155, 13/13-H, 10, 85, 177, 154, and 138. The group agreed to approve retrofit systems together with compatible vehicle families and to exclude hydrogen fuel cell provisions pending further technical input. RME agreed to coordinate benchmarking exercises on power thresholds and range/durability requirements. Future meetings were scheduled for 2 July 2026, 9 September 2026, and 8-9 October 2026.