Session agenda for the 100th meeting of the Electric Vehicles and the Environment Informal Working Group on 13 October 2026. The agenda covers status reports and presentations on UN GTR 22, UN GTR 21, and UN GTR 25, with discussion of Euro 7 review clause, readiness monitoring, and regulatory topics including MPRs, energy throughput, and Part C virtual distance verification.

Working draft proposal to:

• Establish harmonized methods to determine in-vehicle battery durability performance of heavy-duty pure electric vehicles and heavy-duty off-vehicle charging hybrid electric vehicles,
• Introduce State-of-Certified-Energy monitors that estimate battery health throughout vehicle lifetime,
• Define minimum performance requirements for battery durability in an optional annex,
• Establish test procedures for usable battery energy determination via test track driving, on-road driving, bidirectional power supply systems, or chassis dynamometer testing,
• Implement a two-part in-use verification process verifying monitor accuracy and battery durability compliance through statistical sampling,
• Collect field data to inform future revisions of performance requirements.

Report of the 99th session of the EVE IWG held September 8-9, 2026, covering discussions on UN GTR 21, UN GTR 22, and UN GTR 25. Topics included Japan’s proposal to revise UBE certified value calculations, China’s proposal to incorporate fuel cell vehicles under GTR 21, China’s proposals for vehicle category modifications and minimum performance requirements under GTR 25, Japan’s proposals for measurement requirements under GTR 21, assessment of alternative test methods for GTR 25, and open items across all three GTRs. The group confirmed target dates of March 2028 for GTR 21 and GTR 25 amendments.

Proposal to establish harmonised methods for determining in-vehicle battery durability performance of heavy duty pure electric vehicles and heavy duty off-vehicle charging hybrid electric vehicles. The GTR introduces a State of Certified Energy monitor to track battery health over time, defines minimum performance requirements as optional provisions by contracting parties, and specifies in-use verification procedures in two parts: Part A verifies monitor accuracy through measurement of usable battery energy using four alternative test methods, and Part B verifies battery durability against minimum performance requirements through remote data collection from vehicle samples. Virtual distance calculations account for energy used in vehicle-to-grid, power take-off, and non-traction applications.

The agenda addresses UN GTR 22, UN GTR 21, and UN GTR 25, with discussions on fuel cell vehicle proposals, open items, verification results, alternative test methods, and battery replacement provisions. A reminder notes that UN GTR 25 amendment 2 must be submitted to GRPE-96 by December 2026.

The 98th EVE IWG session held virtually on July 15, 2026, adopted the agenda and discussed Phase 4 priorities for UN GTR 22, including Minimum Performance Requirements, State of Certified Range, conditioning cycles, and mutual recognition. Japan proposed sharing Part C verification results with all Contracting Parties. The IWG reviewed UN GTR 21 and UN GTR 25 status, covering MPRs, energy throughput, virtual distance verification, and battery replacement provisions. OICA will present their MPR position at EVE 100 and share Part C verification results at EVE 99. Japan will consult on hosting 2027 meetings targeting the week of February 15th.

Japan proposes to add a specific requirement for vehicle speed measurement frequency of 20 Hz in Table A3/1 of Annex 3, consistent with UN R154; revise para. 2.4 to clarify that both constant and transient cycles test methods are permitted; delete redundant text from para. 2.4.1 regarding test cycle requirements; and delete from para. 5.1 the requirement that resolution and method for SOCE availability be determined in agreement with authorities, as these are already specified.

Technical report on the development of Amendment 1 to UN GTR No. 25 on in-vehicle battery durability for electrified heavy-duty vehicles. The GTR provides a harmonised methodology to monitor battery health over time and introduces minimum performance requirements for battery durability. Development involved approximately 29 IWG meetings over three years with 50 to 60 attendees. The framework centres on minimum performance requirements for in-vehicle batteries, readable on-board battery health monitors, in-use verification procedures, and data collection processes. Three test methods were adopted for measuring usable battery energy: discharge by driving on test track, discharge by driving on road, and discharge using bidirectional power supply system, plus an alternative chassis dynamometer method. The GTR includes an optional annex with minimum performance requirements based on state of certified energy.

The document addresses Part C verification of virtual distance for heavy-duty vehicle batteries. OICA reports pilot phase results from Volvo Group and Daimler Truck AG testing measurement procedures and accuracy under driving and stationary conditions. Key findings show measurement accuracy decreases significantly at lower power levels, with deviations of 0.3% to 4% at higher power. PTO system characteristics influence accuracy; internal PTOs performed better than bodybuilder-installed units. The document identifies challenges including formula correction needs, PTO family concept complexity, and proposes further testing before finalizing Part C requirements.

This document proposes establishing a unified global testing method for determining system power and torque of heavy-duty hybrid electric vehicles (HD-HEV) and heavy-duty plug-in electric vehicles (HD-PEV). The proposal addresses the lack of standardized test methods by recommending hub-coupled dynamometer testing for vehicles with central drive systems and chassis dynamometer testing for other configurations. Testing should measure 30-minute continuous maximum power and torque under thermal equilibrium conditions. The document includes technical data from battery energy distribution analysis and recommends China lead formulation of this standard using chassis dynamometer verification.

Under GTR 25, a feasibility assessment proposes introducing a 5-year mid-term performance requirement threshold together with corresponding mileage and energy-throughput limits as an intermediate verification checkpoint for battery degradation. Based on analysis of State-of-Health data from vehicles with 5-year life and mileage ranging from 250,000 km to 350,000 km, the MPR value is set at 75%, which can cover 98% battery-durability performance. Specific mileage and energy-throughput limits are established for vehicle categories M₂, M₃, N₂, and N₃.

GTR 25 establishes alternative test and verification methods for heavy-duty vehicle energy consumption. China released test method GB/T 18386.2-2022 based on chassis dynamometers using continuous cycle and shortened methods. Test conditions include temperature of 25°C ± 5°C, initial battery SOC of 20%, and pre-conditioning soak and charge for minimum 6 hours and maximum 36 hours. The torque meter method measures road load without disabling regenerative braking, achieving resistance matching within 5% error. Test verification includes vehicle selection across mileage groups 0, 200,000, 400,000, and 600,000 km, with on-board data collection and sensor accuracy consistency analysis post-durability.

China introduces an assessment of low State of Charge Energy requirements for M-type vehicles using data from city buses and coaches. At low SOCE levels, available energy is reduced, requiring increased initial battery energy capacity to meet customer driving range expectations, leading to higher purchase costs and vehicle weight. China provides reasons supporting SOCE performance targets at an 8-year timeframe, including significant differences in vehicle types, operating conditions, business models, and battery specifications that vary by vehicle type, making uniform standards inefficient.

Proposal to revise the weight threshold of M₃ vehicle category from 7.5 tonnes to 12 tonnes, split N-type trucks into three categories with light-duty trucks below 5 tonnes, medium-duty trucks above 5 tonnes and N₃ below 18 tonnes, and heavy-duty trucks above 18 tonnes, adjust year and mileage limits for N₂, N₃ medium-duty trucks to 8 years or 500,000 km, and establish energy throughput requirements: M₂ 120,000 kWh, M₃≤12t 300,000 kWh, M₃>12t 500,000 kWh, N₂≤5t 200,000 kWh, N₂>5t, N₃≤18t 400,000 kWh, N₃>18t 1,200,000 kWh.

UN GTR No. 25 on In-vehicle Battery Durability for Electrified Heavy Duty Vehicles provides harmonised methods to determine battery durability performance of HD-PEVs and HD-OVC-HEVs of categories M₁–M₃ and N₁–N₃ exceeding 3,855 kg MPLM. The regulation requires manufacturers to install State of Certified Energy (SOCE) monitors throughout vehicle lifetime. In-use verification consists of Part A verification of monitor accuracy through measured UBE testing using Methods 1a, 1b, Method 2 (bidirectional power supply), or an alternative HDV chassis dynamometer method, with statistical pass/fail criteria. Part B verification assesses battery durability against optional Minimum Performance Requirements (MPRs) through remote SOCE data collection from sample vehicles. Part C verification, reserved for future amendment, will address reported virtual distance accuracy for V2X, PTO and non-traction purpose applications. Optional Annex 4 specifies MPRs by vehicle category and mass, ranging from 45–70% SOCE retention across specified timeframes and distances. The GTR entered into force with Phase 1 covering core durability assessment and data collection to support future refinement of MPR thresholds based on in-service field data relating to HDVs, referencing WP.29-170-31 and GRPE/2026/3.

The agenda for the Electric Vehicles and the Environment Informal Working Group 98th session scheduled for July 15, 2026, includes presentations on battery performance, discussions on UN GTR 21, UN GTR 22, and UN GTR 25 regulatory topics including minimum performance requirements, state of charge reference, readiness monitor and conditioning cycles, mutual recognition, fuel cell electric vehicles, highly integrated systems, energy throughput, normal usage indices, and battery replacement provisions. UN GTR 25 amendment 2 must be submitted to March 2027 GRPE with a December 2026 deadline.

Proposal to establish harmonised methods for in-vehicle battery durability of electrified heavy-duty vehicles:

• Establish harmonised methods for determining in-vehicle battery durability of electrified heavy-duty vehicles (categories 1-2 and 2 with technically permissible maximum laden mass exceeding 3,855 kg) that are pure electric or off-vehicle charging hybrid electric vehicles,
• Require manufacturers to install and maintain State-of-Certified Energy (SOCE) monitors throughout vehicle lifetime at resolution of at least 1 part in 100, making values available via on-board diagnostics port and optionally over-the-air,
• For Contracting Parties electing to enforce minimum performance requirements from optional Annex 4, require manufacturers to ensure compliance through in-use verification comprising Part A (monitor accuracy verification through measured usable battery energy testing via driving on test track/road or bidirectional power supply system, with statistical pass/fail criteria) and Part B (battery durability verification through remote data collection from vehicle sample of minimum 500 vehicles annually, requiring at least 90 per cent of monitored values above applicable minimum performance requirement or declared performance requirement),
• Reserve Part C verification of virtual distance accuracy for future amendment,
• Specify minimum performance requirements with SOCE retention percentages (45–70 per cent) at defined time and distance combinations varying by vehicle category and mass, to be monitored during phase 1 for potential future revision based on energy throughput data.