What is the UL1973 Safety Standard Test in the US?

UL1973, the second edition released on February 7, 2018, is the safety standard for energy storage battery systems in North America, and it serves as a dual standard for both the United States and Canada. The standard primarily covers various types of battery systems used in stationary, vehicle auxiliary power, LER, photovoltaic, wind energy, backup power, and communication base stations. It includes structural and testing assessments of energy storage systems, but this standard only addresses safety and does not include performance and reliability assessments.

The UL1973 standard applies to the following types of batteries:

1. Energy storage applications: Photovoltaic power plants, wind power plants, UPS, home energy storage, etc.

2. Vehicle auxiliary batteries (excluding propulsion batteries).

3. Batteries used in light rail or fixed rail energy storage systems, without limitation on battery chemistry.

4. Includes various types of batteries, with no restrictions on chemistry, including beta sodium batteries and flow batteries.

5. Electrochemical systems.

6. Hybrid systems of batteries and electrochemical capacitors.

Regular Testing Items for UL1973 Stationary Energy Storage Batteries:

1. Overcharge

2. Short Circuit

3. Overdischarge Protection

4. Temperature and Operating Limits Check

5. Imbalanced Charging

6. Dielectric Voltage Withstand

7. Continuity

8. Failure of Cooling/Thermal Stability System

9. Working Voltage Measurements

10. Locked-Rotor Test

11. Input Testing

12. Strain Relief/Push-Back Relief

13. Vibration

14. Shock

15. Crush

16. Static Force

17. Impact

18. Drop Impact (rack-mounted module)

19. Wall Mount Fixture/Handle Test

20. Mold Stress

21. Pressure Release

22. Start-to-Discharge

23. Thermal Cycling

24. Resistance to Moisture

25. Salt Fog

26. External Fire Exposure

27. Single Cell Failure Design Tolerance

Documents Required for UL1973 Certification:

1. Battery Cell Specifications

 (including rated voltage, capacity, discharge current, cutoff discharge voltage, charge current, charge voltage, maximum charge current, maximum discharge current, maximum charge voltage, maximum operating temperature, product overall dimensions, product weight, etc.)

2. Battery Pack Specifications

 (including rated voltage, capacity, discharge current, cutoff discharge voltage, charge current, charge voltage, maximum charge current, maximum discharge current, maximum charge voltage, maximum operating temperature, product overall dimensions, product weight, etc.)

3. Internal and External Product Photos

4. Circuit Schematic or System Block Diagram

5. Key Component List/BOM (Bill of Materials)

6. Detailed Circuit Schematic

7. Component Placement Diagram for the PCB

8. Battery Pack Structural Assembly Diagram or Exploded View

9. System Safety Analysis (e.g., FMEA, FTA)

10. Key Component Dimension Drawings or Technical Specifications

(e.g., heatsinks, busbars, metal parts, transformers, main protection fuses, etc.)

11. Battery Pack Production Date Codes

12. Battery Pack Labels

13. Battery Pack User Manual

14. Other Documents Required for Certification