Global Regulatory Approaches to Second-Life Battery Deployment

The deployment of second-life batteries, repurposed from electric vehicles (EVs) and other applications into stationary storage or less demanding roles, presents unique regulatory challenges. Governments and industry bodies have developed frameworks to address safety, performance, and liability concerns while encouraging market growth. The regulatory landscape varies significantly between the EU, US, and Asia, shaping the pace and scale of second-life battery adoption.

Safety Certifications and Standards

Safety remains the primary concern for second-life batteries due to potential degradation from prior use. Regulatory approaches differ in certification requirements and testing protocols.

In the EU, second-life batteries must comply with the Battery Directive and the upcoming EU Battery Regulation, which includes specific provisions for repurposed energy storage systems. Manufacturers must demonstrate compliance with IEC 62619 for stationary storage safety and provide detailed historical data on battery health. The EU emphasizes extended producer responsibility (EPR), requiring original manufacturers to ensure safe second-life deployment.

The US lacks federal-level regulations specifically for second-life batteries, relying instead on a combination of state policies and voluntary standards. Underwriters Laboratories (UL) provides safety certifications such as UL 1974 for repurposed batteries, but adoption is inconsistent. California leads with stricter requirements, mandating safety testing akin to first-life batteries under its energy storage rules.

Asian markets show divergent approaches. China enforces GB standards, requiring rigorous safety testing before redeployment, including thermal runaway assessments. Japan follows a more flexible model, with the Japan Electrical Safety and Environment Technology Laboratories (JET) certifying second-life systems based on residual capacity thresholds. South Korea integrates second-life batteries into its renewable energy mandates but imposes strict liability on original manufacturers.

Performance Warranties and Quality Assurance

Performance warranties for second-life batteries are less standardized than for new systems, creating market uncertainty.

The EU encourages standardized performance metrics through the European Association for Storage of Energy (EASE), which recommends capacity retention warranties (typically 70-80% of original capacity) for second-life systems. However, warranties remain shorter than for new batteries, usually capped at five years.

In the US, warranties are market-driven, with some providers offering performance guarantees tied to remaining useful life estimates. Tesla’s second-life Powerwall deployments, for example, include limited warranties based on historical cycling data. The absence of federal oversight leads to variability in warranty terms.

China mandates minimum performance thresholds for second-life batteries used in grid storage, requiring 70% residual capacity and cycle life testing. Japan’s approach relies on industry consortia to set voluntary warranty benchmarks, while South Korea ties warranty requirements to subsidy eligibility.

Liability and Insurance Considerations

Liability frameworks determine risk allocation between original manufacturers, second-life operators, and end-users.

The EU’s EPR model extends liability to manufacturers even after repurposing, creating legal obligations for safety and performance. This discourages some manufacturers from engaging in second-life markets due to perceived risks. Insurance products are emerging but remain costly due to uncertain degradation patterns.

The US follows a more fragmented liability model. Original manufacturers often disclaim responsibility post-first-life, shifting liability to second-life operators. Insurance coverage varies by state, with some providers offering specialized policies for repurposed storage systems. California’s regulations impose shared liability, requiring clear contractual delineation of responsibilities.

In Asia, China holds manufacturers liable for safety incidents throughout the battery’s lifecycle, including second-use phases. Japan’s system limits manufacturer liability post-repurposing but requires operators to carry mandatory insurance. South Korea imposes strict liability on all parties in the value chain, increasing compliance costs.

Market Development Impacts

Regulatory differences significantly influence market dynamics.

The EU’s stringent safety and liability rules slow deployment but ensure higher-quality second-life systems. The emphasis on EPR creates a structured market but increases costs for manufacturers.

The US market grows faster due to regulatory flexibility but faces inconsistency in safety and performance standards. State-level policies create uneven opportunities, with California dominating second-life deployments.

Asia’s mixed approach yields varied outcomes. China’s top-down regulations drive rapid adoption in grid storage, while Japan’s voluntary framework fosters niche applications. South Korea’s liability rules deter smaller players but ensure system reliability.

End-of-Life Responsibilities

Regulations governing final disposal after second-life use further shape market behavior.

The EU requires second-life operators to plan for eventual recycling, with costs often borne by original manufacturers under EPR. This closed-loop approach incentivizes design for recyclability.

The US leaves end-of-life management to state policies, leading to patchwork solutions. Some states mandate recycling, while others lack clear directives.

China enforces strict recycling quotas for second-life batteries, with licensed processors handling disposal. Japan promotes reuse until batteries degrade below 50% capacity before mandating recycling.

Conclusion

Global regulatory approaches to second-life batteries reflect balancing safety, market growth, and liability concerns. The EU prioritizes comprehensive safety and producer responsibility, the US favors market-driven flexibility, and Asia employs a mix of mandates and incentives. These differences create distinct challenges and opportunities for stakeholders, influencing the pace of second-life battery adoption worldwide.