UL Certification Helps Promote Repurposing of Electric Vehicle (EV) Batteries

Author: Maurice H. Johnson, product manager, Energy & Industrial Automation

As electric vehicle (EV) batteries near the end of their initial service life, they begin to lose power. However, these batteries often have 70-80% of usable energy capacity even after they are removed from vehicles. To avoid adding usable batteries as e-waste in landfills, UL Standards & Engagement developed ANSI/CAN/UL 1974, the Standard for Evaluation for Repurposing Batteries, a Standard that provides requirements for the sorting and grading process of batteries that are intended for repurposing. The standard also covers application specific requirements for repurposed battery packs/systems and battery packs/systems utilizing repurposed modules, cells and other components.

Successfully repurposing EV batteries depends on a reliable process that helps mitigate risk and sustainability for energy system asset owners. Every battery should be evaluated individually for safety risks because each battery has been exposed to different charging and discharging conditions during its use in an EV. To promote EV battery repurposing, UL Standards & Engagement has worked with input from automakers, battery reclaimers, utility providers and academics to develop UL 1974.

Even though used EV batteries may no longer be suitable for electric vehicle propulsion, they can be repurposed for applications such as stationary energy storage systems (ESS) that require lower power efficiency. UL 1974 helps to support battery safety and sustainability by including requirements for repurposing facilities covering:

• Quality control processes review
• Safety evaluation of repurposing facilities
• Examination and sorting processes
• Initial and subsequent rejection procedures
• Visual inspection of incoming batteries
• Gathering and analysis of Battery Management System (BMS) data from each battery
• Disassembly and examination procedures
• Grading of batteries for repurposing
• Proper disposal of damaged and rejected parts
• Markings and instructions

UL Solutions Certification for Battery Repurposing Facilities

As there are no specific requirements in the most current model building or fire codes, designers and code authorities may use the alternate materials and methods provision of the codes to address construction and operation of any battery repurposing facilities. Neither the 2021 International Fire Code (IFC) or the finalized 2024 IFC contain requirements specifically addressing the hazards associated with facilities repurposing or recycling lithium or lithium-ion batteries. Code authorities can utilize a certification to UL 1974 for battery repurposing facilities, which includes investigation of fire and explosion risks, in their approval process.  The UL Solutions certification of repurposing facilities in accordance with UL 1974 provides code authorities with additional confidence in the safer operation of these facilities.

UL Solutions audits and certifies battery repurposing facilities to UL 1974. This includes assessing the process for sorting and grading battery cells, packs and modules, and assessing the process determining a battery’s continued viability and rating mechanisms for continued use. Once UL Solutions audits that the processes are being followed, and when confirmed, a facility earns a second-life battery facility certification. The UL Solutions facility certification is valid for three years following the date of issuance. A current list of certificate holders can be accessed using UL Product iQ^® under UL Solutions product category PDXT. Product iQ is a complimentary search tool, but does require a simple one-time registration.

All batteries that have been safely repurposed by facilities certified to UL 1974 must still undergo testing and certification for their new intended use such as for use in an ESS. Repurposed batteries that will be used for ESS must be certified in accordance with UL 1973, Batteries for Use in Stationary and Motive Auxiliary Power Applications (UL Solutions product category BBFX) with the entire ESS being certified to UL 9540, Energy Storage Systems and Equipment (UL Solutions product category FTBW).

Battery Storage Requirements Added to the 2024 IFC

Lithium-ion and lithium metal batteries stored in facilities producing new batteries or repurposing used batteries will have additional requirements that have been approved for the 2024 IFC to help mitigate the hazards associated with the battery storage at such facilities. Highlights of these requirements include:

• Operation permit for the storage of batteries, based on chemistry and quantity; with allowances for additional storage where batteries have a state of charge less than 30%
• Separation of storage areas by two-hour fire resistance-rated construction
• Preparation and submittal of a fire safety plan
• For indoor storage, a technical opinion report to evaluate the fire and explosion risks and provide recommendations for fire and explosion protection
• Protection by fire sprinkler and fire detection systems
• Explosion control based on the technical opinion report
• For outdoor storage, separation distances and fire detection using radiant energy-sensing

Interested in participating in the UL Standards & Engagement Standard Development Process?

UL Standards are developed through a consensus-based process that integrates scientific and testing expertise with input from Standards Technical Panel (STP) members and stakeholders. An STP is a group of individuals, representing a variety of interests, formed to review proposals related to UL Standards. If you are involved in the approval of battery repurposing facility inspection or approval for the safe operation and code compliance of these facilities, and you would like to help improve safety for these installations, please submit a proposal request to revise the UL 1974 Standard or an STP application to apply for STP 1974 membership through UL’s Collaborative Standards Development System (CSDS).

For more information related to product or system listing (certification) from UL Solutions, please contact ULRegulatoryServices@ul.com.