Detailed Analysis

1. UL 9540A — The "Fire Safety Passport" for Thermal Runaway Propagation

Standard Positioning: Test Method (not a product certification mark), but mandatory requirement

Core Objective: Verify whether flames/high-temperature gases propagate to adjacent cells or cabinets when a single cell undergoes thermal runaway

Four-Tier Testing Hierarchy:

Cell Level: Determine thermal runaway trigger method and gas generation volume

Module Level: Verify propagation within module boundaries

Unit Level: Verify cabinet/container-level propagation characteristics

Installation Level: Assess room/building-level fire protection strategies (gas concentration, smoke venting design)

2. UL 1973 — The Universal Safety Baseline for Stationary Storage & Industrial Vehicles

Covered Products:

ESS energy storage systems (stationary applications)

forklift lithium power batteries (light electric vehicles, replacing lead-acid)

Residential energy storage, data center backup power, etc.

Testing Focus:

Electrical Safety: Overcharge, over-discharge, short circuit, dielectric withstand

Mechanical Safety: Vibration, shock, drop, crush (simulating forklift operating conditions)

Environmental Safety: High temperature, low temperature, thermal cycling, salt spray (for industrial environments)

Thermal Runaway: Requires system-level thermal runaway detection and response capability (less stringent than 9540A)

Relationship with 9540A: UL 1973 certification typically requires accompanying UL 9540A test reports to constitute a complete energy storage safety system.

 3. UL 2580 — The High-Threshold Safety Standard for Electric Vehicles

Standard Positioning: Automotive-grade product safety certification

Target Applications: Electric passenger/commercial vehicle power batteries (high voltage, high energy density)

Key Differentiators:

Mechanical Abuse: More stringent crush testing (simulating vehicle collisions), nail penetration (more critical for ternary lithium chemistries)

Submersion Testing: Simulating vehicle wading scenarios

Thermal Runaway Requirements: Permits thermal runaway but mandates 5-minute evacuation time (no propagation to passenger compartment)