What is the PSE Certification of Lithium Battery?

PSE certification is a critical safety requirement for lithium batteries entering the Japanese market. It confirms that the product complies with Japan’s Electrical Appliance and Material Safety Act and meets defined standards for electrical safety, insulation, and fire risk control.

For manufacturers, understanding the PSE process is essential to avoid customs issues, shipment delays, or product recalls. For distributors and end users, the PSE mark provides assurance that lithium batteries have been evaluated against Japan’s safety expectations.

In this article, we will explain the fundamentals of PSE certification for lithium batteries, why it is important, how the process works, and how it compares with other major certifications such as CE, UL, and KC. This will help both manufacturers and buyers make informed decisions when designing, sourcing, or selling lithium batteries for the Japanese market.

Part 1. What is PSE Certification?

PSE certification is Japan’s mandatory safety scheme for many electrical appliances and materials. PSE stands for “Product Safety Electrical Appliance and Materials” and is based on the Electrical Appliance and Material Safety Act, commonly known as the DENAN Law.

Lithium batteries that fall within the scope of this law must comply with its technical requirements and, in certain categories, obtain PSE certification before being sold on the Japanese market.

Regulatory Background

The Electrical Appliance and Material Safety Act is administered by Japan’s Ministry of Economy, Trade and Industry (METI).
METI:

• Defines which products are covered as “Specified Electrical Appliances and Materials” and “Non-specified Electrical Appliances and Materials”
• Approves and supervises Registered Conformity Assessment Bodies (RCABs) that perform third-party testing and certification for specified products
• Oversees market surveillance and enforcement

Legal and Safety Requirements for Lithium Batteries

For lithium batteries that fall under DENAN, PSE-related requirements typically include:

Safety Standards
PSE compliance confirms that lithium batteries meet Japanese safety standards. This involves electrical safety, thermal stability, insulation performance and fire prevention, especially under abnormal or misuse conditions.

Consumer Protection
The PSE framework is designed to protect users from risks such as short circuits, overheating, venting or fire. Products that carry the PSE mark give retailers and consumers greater confidence in their safety.

Legal Compliance
Manufacturers, importers and brand owners need PSE conformity to sell covered lithium batteries legally in Japan. Non-compliance can result in administrative actions, product seizure, sales suspension and financial penalties.

Market Access
Without PSE compliance for in-scope products, access to the Japanese market is effectively blocked. For battery manufacturers and pack assemblers, PSE is a key prerequisite for sustainable business in Japan.

Part 2. PSE Certification Process for Lithium Batteries

The exact process can vary depending on whether the product is classified as a “Specified” or “Non-specified” appliance. For many lithium batteries that are treated as specified products, a third-party conformity assessment by a Registered Conformity Assessment Body (RCAB) is required.

1. Application and Documentation

Preparation
Before submitting an application, manufacturers should ensure that their lithium batteries are designed to meet relevant Japanese safety standards. Internal pre-testing is highly recommended.

Select a Certification Body
Choose a METI-recognized Registered Conformity Assessment Body (for example, an accredited testing and certification organization approved to handle PSE). METI itself does not test products but oversees the system.

Submit Application
Provide detailed information about the battery, including:

• Electrical ratings and chemistry
• Intended use and applicable product category
• Mechanical design and enclosure structure

Documentation Submission
Typical documentation includes:

• Technical specifications and drawings
• Safety data sheets (SDS)
• Previous relevant test reports, if available
• Information on protection circuitry and BMS functions

Payment of Fees
Pay the assessment and testing fees required to initiate the certification process.

2. Testing and Evaluation

Document Review
The certification body first reviews the submitted documentation to check completeness, product classification and apparent compliance with applicable standards.

Laboratory Testing
Accredited laboratories then perform safety tests on the lithium batteries. These usually cover:

• Electrical safety
• Thermal behavior and stability
• Insulation and dielectric strength
• Abnormal operation and misuse conditions

Performance Evaluation
Depending on category and test plan, evaluations may also include:

• Capacity and charge/discharge behavior
• Cycle life under defined conditions
• Behavior under temperature extremes

The primary focus remains safety, but performance stability is also considered to ensure predictable behavior in real-world use.

3. Certification and Labeling

Review of Test Results
The certification body reviews all test data, documentation and any corrective actions.

Issuance of PSE Certificate
If all requirements are satisfied, the certification body issues a PSE certificate or report confirming conformity.

Use of the PSE Mark
Certified products must display the appropriate PSE mark (diamond or circle, depending on classification) on the product and, where applicable, on packaging and documentation.

Guidelines for Proper Labeling

Manufacturers and importers should:

• Apply the correct PSE symbol for the applicable category
• Include the name or identification of the responsible party in Japan
• Provide clear instructions and safety warnings in product manuals
• Maintain complete records of certificates, test reports and technical files for regulatory inspection

Part 3. Importance of PSE Certification for Lithium Batteries

Ensures Safety
PSE certification verifies that lithium batteries meet strict Japanese safety requirements. This reduces the risk of overheating, fire, electric shock or other hazardous events in daily use.

Enhances Trust
Retailers and consumers in Japan are familiar with the PSE mark. Products that display it are perceived as safer and more reliable, which supports brand credibility.

Facilitates Market Access
For covered products, PSE is a prerequisite for legal sale in Japan. Without it, distributors and retailers will not accept the product, regardless of other international certifications.

Prevents Legal Issues
Complying with PSE requirements protects manufacturers and importers from enforcement actions, recalls and reputational damage caused by non-compliant or unsafe products.

Part 4. Understanding PSE Certification Symbols

When dealing with the Japanese market, it is important to understand the meaning of the two main PSE marks that may appear on products, including battery-powered equipment and certain battery types.

Diamond-Shaped PSE Mark (PSE Diamond)

• Used for “Specified Electrical Appliances and Materials” under the DENAN Law
• Indicates that the product has undergone third-party conformity assessment by a Registered Conformity Assessment Body
• Confirms that the product meets the relevant technical and safety requirements and is legally permitted for sale in Japan for that category

For lithium batteries that are classified as specified products, this diamond mark is typically applicable.

Circular PSE Mark (PSE Circle)

• Used for “Non-specified Electrical Appliances and Materials”
• Indicates that the manufacturer (or importer) has ensured compliance with applicable safety requirements and performed the necessary conformity assessment
• Does not mean “not certified,” but rather that conformity is based on a manufacturer responsibility model instead of mandatory third-party certification

In some cases, lithium batteries may be integrated into equipment that carries the PSE mark as a whole product, rather than the battery being marked separately.

Part 5. Comparison With Other International Certifications

PSE vs CE Certification

Scope and Region

• PSE: Focuses on safety and compliance under Japanese law, specifically for the Japan market
• CE: Applies to the European Union and EEA, covering health, safety, EMC and environmental aspects according to EU directives and regulations

Testing and Conformity Approach

• PSE: Uses Japanese technical requirements and, for specified products, requires third-party assessment by an approved body
• CE: Generally based on manufacturer self-declaration, referencing harmonized EN standards. Third-party involvement (Notified Body) is required only for certain high-risk categories

Regulatory Oversight

• PSE: Supervised by METI, with testing performed by Registered Conformity Assessment Bodies
• CE: Oversight is shared across EU member state authorities, with Notified Bodies involved depending on product category

Regional Applicability

• PSE Certification: Mandatory for in-scope products sold in Japan
• CE Marking: Mandatory for covered products sold in the EU and EEA

PSE vs UL Certification

Role and Region

• PSE: A legally required compliance scheme under Japanese law for specific electrical products, including some lithium batteries
• UL: A widely recognized safety certification system primarily used in North America, operated by Underwriters Laboratories and other NRTLs, often required by retailers and buyers even though it is not a government law

Safety and Performance Focus

• PSE: Focuses on compliance with Japanese safety requirements, including electrical, thermal and fire risks
• UL: Focuses on safety and fire risk, with standards such as UL 1642, UL 2054 and UL 2580 for different battery applications

Market Impact of Holding Both

• Increased Market Access: Having both PSE and UL approvals gives a battery manufacturer or integrator access to Japan as well as North American markets
• Enhanced Credibility: Dual certification demonstrates a strong commitment to safety, making it easier to work with global OEMs, distributors and brand owners
• Competitive Advantage: Products with both PSE and UL tend to be more attractive to international buyers who prioritize safety and regulatory readiness

By aligning lithium battery design and testing with PSE, CE, UL and other key certifications, manufacturers can build a robust compliance strategy that supports both safety and global market expansion.

Part 7. FAQs

How long does it take to obtain PSE certification for lithium batteries?

The timeframe for obtaining PSE certification depends on several factors, including the completeness of the application, the workload of the certification body and the complexity of the required testing. In practice, the process often takes from several weeks to a few months. Projects that require design changes after initial testing or additional documentation reviews may take longer.

Can I apply for PSE certification for lithium batteries online?

Yes. Many Registered Conformity Assessment Bodies provide online portals for submitting PSE applications, uploading documents and tracking project status. However, you will still need to provide complete technical documentation and physical battery samples for testing. Some paperwork may be submitted electronically, while signed originals may occasionally be required depending on the certification body’s procedures.

What are common reasons for rejection of PSE certification applications?

Typical causes of delay or rejection include:

• Incomplete or inconsistent technical documentation
• Failure to meet safety requirements during testing
• Differences between the submitted documentation and the actual product samples
• Non-compliance with labeling and marking rules
• Lack of clarity about the responsible manufacturer or importer in Japan

Thorough preparation, internal pre-testing and clear documentation can significantly reduce these risks.

Is PSE certification mandatory for all lithium batteries sold in Japan?

PSE conformity is mandatory for products that fall within the scope of the Electrical Appliance and Material Safety Act (DENAN). Certain categories of lithium batteries and battery-powered products are covered and must comply with PSE requirements to be sold legally in Japan.

Not every lithium battery in every form is automatically classified under DENAN, so it is important to:

• Confirm the exact product category
• Check whether the battery or battery-powered equipment is treated as a specified or non-specified appliance
• Consult METI guidance or a PSE certification body if there is any doubt about scope

For in-scope products, selling without meeting PSE requirements can lead to enforcement actions, sales suspension and legal penalties.

Can I use an existing PSE certification for a new lithium battery model?

In most cases, no. Each distinct lithium battery model or family requires its own conformity assessment. If the design, capacity, construction, cell type or protection circuitry changes, the product is normally treated as a new model and must undergo a separate evaluation.

In some limited cases, closely related models may be grouped into a single certification family if agreed with the certification body and if technical differences are minor. However, assuming that a previously obtained PSE certificate automatically covers a new design is risky. Manufacturers should always confirm with the certification body whether additional testing or a new certificate is required.