Overview - EN ISO 23625:2025 (Small craft - Lithium‑ion batteries)
EN ISO 23625:2025 specifies requirements and recommendations for the selection, installation and safety information for lithium‑ion batteries on small craft. It applies to lithium‑ion batteries and battery systems with a capacity greater than 500 Wh used for general electrical loads and/or electric propulsion. The standard is primarily intended for manufacturers and battery installers and is the European adoption of ISO 23625:2025.
Key topics and technical requirements
- Scope and applicability: Batteries > 500 Wh on small craft; warning that DC systems operating at 60 V or higher may have additional safety requirements beyond this document.
- System design requirements: Installations must follow ISO 13297 and the battery manufacturer’s recommendations; designs must keep batteries within the manufacturer’s Safe Operating Limits (SOL).
- Battery Management System (BMS): Mandatory BMS to protect against overcharge, overdischarge, high/low temperature events, and to provide cut‑outs (HVC, LVC, HTC, LTC). EMC requirements for BMS are included.
- Safe operating limits and monitoring: Definitions and requirements for state of charge (SOC), C‑rating, ampere interrupt capacity (AIC), and temperature limits.
- Fire protection and venting: Guidance on mitigating thermal runaway risks and cell venting-annexes provide expanded information on thermal runaway mechanisms and protection devices.
- Manufacturer’s safety information: Required content for safety documentation and operator manuals, including audible alarm specifications (75–85 dB(A) at 1 m from the command station).
- Testing and referenced standards: Incorporates or references IEC 62619 and IEC 62620 (cell and battery safety), ISO 13297, IEC 60529 (IP code), and other normative documents.
Practical applications and users
- Who uses it: Boat builders, battery and BMS manufacturers, system integrators, marine electricians, and certification bodies.
- When to apply: During design, selection, installation, commissioning and documentation of lithium‑ion battery systems on yachts, recreational boats and other small craft.
- Benefits: Reduces risk of fire and battery failure, ensures regulatory alignment across CEN member states, improves operator safety through clear manufacturer information and standardized BMS responses.
Related standards
EN ISO 23625:2025 is essential for marine professionals working with lithium‑ion battery systems, helping ensure compliant, safe and reliable energy installations aboard small craft.
