With the rapid development of the global electric mobility industry, the dynamic evolution of technical regulations in the EU—a pivotal market—remains a focal point for the sector. The ECE R136 regulation, issued by the United Nations Economic Commission for Europe (UNECE), serves as the mandatory safety benchmark for electric two/three-wheelers (L-category vehicles) and their Rechargeable Energy Storage Systems (REESS) to enter the European market. Its latest revised version—Revision 01—has officially entered into force. This update is not a minor tweak but introduces more forward-looking and stringent technical requirements for lithium battery system safety. All vehicle manufacturers, battery system suppliers, and export enterprises targeting the EU and relevant contracting parties must fully understand these changes and complete product upgrades and certification transitions by the deadline of September 1, 2025.

I. Core Regulatory Update: Introduction of the Mandatory Overcurrent Test

The most prominent and critical technical change in Revision 01 is the addition of a new mandatory test item—Overcurrent Protection Test—to the existing suite of rigorous tests.

1. Test Purpose & Background

This test aims to evaluate the safety protection capabilities of the REESS (battery pack) and its Battery Management System (BMS) when subjected to abnormal high-current impacts. It simulates sudden overcurrent conditions that may occur during actual vehicle operation due to controller malfunctions, motor lock-up, or other electrical anomalies. The inclusion of this test reflects regulators’ heightened focus on the full-scenario operational safety of electric vehicles, particularly risk prevention under electrical abuse conditions.

2. Test Requirement Interpretation

According to Revision 01, the test requirements can be summarized as follows:

• Test Object: Complete REESS or its subsystems.
• Test Method: Under specified ambient test temperatures, apply an overcurrent value to the test sample that is higher than the manufacturer’s stated maximum operating current but lower than its external short-circuit current.
• Pass Criteria: The system must trigger effective protective measures (e.g., fuse disconnection, contactor tripping) within the specified timeframe (usually requiring immediate action). It must also ensure no hazards such as fire, explosion, or leakage occur during and for a period after the test.

3. Comparison with Previous Revision 00 Requirements

The previously enforced Revision 00 already included tests such as external short-circuit, overcharge, overdischarge, and over-temperature protection. The newly added overcurrent test fills the grey area between "external short-circuit" and "normal operation", forming a more continuous and comprehensive electrical abuse test spectrum. It imposes higher requirements on the BMS’s current monitoring accuracy, protection logic response speed, and the coordination of the vehicle’s overall electrical architecture.

II. Key Timelines & Transition Period Arrangements

The regulatory transition features clear timelines, and enterprises must strictly adhere to the following schedule:

Special Reminder: Considering the certification testing cycle, potential rectification work, and certification body review timelines, it is strongly recommended that enterprises initiate Revision 01 certification projects for new products at least 6–9 months in advance. This avoids last-minute application backlogs and delays to market access plans.

III. Industry Chain Challenges & Response Strategies

1. Challenges for REESS & BMS Suppliers

The overcurrent test directly challenges the BMS’s hardware sampling accuracy and software protection strategies. Suppliers need to:

• Re-evaluate and verify the reliability of existing BMS overcurrent detection thresholds, response delays, and protective actions.
• Upgrade necessary hardware components, such as higher-precision current sensors and more reliable actuators (contactors, fuses).
• Collaborate closely with vehicle manufacturers to clarify key parameters at the vehicle level, including maximum operating current and fault current definitions.

2. Challenges for Vehicle Manufacturers

As the responsible entities for certification, vehicle manufacturers must:

• Immediately launch product compliance reviews to identify adjustments required for in-production and under-development models.
• Update technical documentation, including revised technical specifications, BMS protection strategy descriptions, and electrical safety design reports.
• Coordinate the supply chain to ensure that battery packs, BMS, motor controllers, and other components meet the new regulations and have supporting compliance evidence.

3. Response Strategy: Partner with Professional Testing & Certification Bodies

Faced with these strict and specialized regulatory updates, collaborating with testing and certification institutions with profound technical expertise and official qualifications is the most efficient and reliable path to compliance. Professional institutions can:

• Provide precise gap analysis to help quickly identify discrepancies between existing designs and Revision 01 requirements.
• Offer pre-testing and rectification guidance to detect and resolve issues before formal certification, saving time and costs.
• Complete full-project formal testing and issue authoritative reports, laying the foundation for obtaining E-mark certificates.

IV. Conclusion & Call to Action

The implementation of ECE R136 Revision 01 marks a new phase of more refined and stringent safety standards for global electric light-duty vehicles. The newly added overcurrent test is the technical core of this update, and September 1, 2025, is an unmissable regulatory deadline.

For enterprises aiming to deepen their presence in the European market, passive waiting means lost market opportunities. We urge all relevant enterprises to:

1. Initiate Immediately: Assemble internal technical and compliance teams to conduct an in-depth review of the Revision 01 regulatory text.
2. Conduct Precise Assessments: Perform comprehensive compliance evaluations of existing product platforms and new product plans.
3. Seek Collaboration: Engage with professional testing and certification partners as early as possible to develop a detailed certification transition roadmap and timeline.

Only by proactively addressing regulatory requirements and achieving compliance can enterprises turn regulatory challenges into competitive advantages in product safety and technological leadership, ensuring stable and long-term development in the EU—the high ground of green mobility.