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Li Ion Batteries in Japan

If you are planning to market your Li ion batteries in Japan, you will need to understand the requirements and exceptions for compliance with the Japanese Electrical Appliance and Material Safety Law (also known as the DENAN Law).  Li ion cells and batteries are on the “List of Other Electrical Appliances and Materials (Category B)” under the DENAN Law.  This means these products will require a self-certification and registration on the part of the importer or manufacturer of Li Ion batteries in Japan.  The regulation applies to importers as well as manufacturers of Li Ion batteries in Japan.  Once the testing and registration is completed this allows the application of the PSE mark on the product.  The applicable mark for Li Ion products is the circular mark as shown below.

 

PSE Mark for Li Ion Batteries in Japan

PSE Mark

There are some exceptions to the application of the law however.  The “List of Other Electrical Appliances and Materials (Category B)” specifically states that it applies to “Lithium-ion batteries (limited to those consisting of secondary cell of which energy density is not less than 400Wh/L, but excluding those used in automobiles, motorcycles, medical appliances, industrial appliances).”  This specifically excludes a battery, regardless of the size of the battery, which is constructed of cells that have a volumetric energy density of less than 400Wh/L.  A typical 18650 cell is going to exceed this limit and require the cell and battery pack to both comply with the regulation.  As stated in the list, the regulation also limits the end use applications covered by specifically excluding batteries that will be used in automotive, motorcycle, medical and industrial applications.

In addition to these limitations from the list, there is a cabinet order that provides another limitation.  It states that Li Ion batteries “designed to fix to appliances by soldering or other joining methods so that it cannot be easily removed” are excluded.  This is specifically referring to embedded batteries that are internal to an end device like a tablet for example.  The only issue that can arise with these exclusions is if you plan to ship Li Ion batteries in Japan without the end device.  This can be done for repair centers, replacement sales, or in country distribution requirements.  In these cases, it would be advisable to comply with the regulations since you may have issues showing that your battery fits the exclusion when it is not transported with the end device.

The testing requirements for Li Ion cells and batteries are given in the “Revision of the Ministerial Ordinance for Determining Technical Standards for Electrical Appliances (Lithium Ion Secondary Batteries)” and they are not completely harmonized to any international standards.  The following is a summary of the test requirements for cells and batteries under the Ordinance compared to the IEC62133 standards, both first and second edition.

DENAN Law Cell Battery
IEC62133:2002 IEC62133:2012 IEC62133:2002 IEC62133:2012
Continuous low rate charging (cells only) JAPAN – test at temperature IEC is shorter duration and not at temperature
Vibration Same Not required for IEC Same Not required for IEC
Battery enclosure test at high ambient temperature (battery only) Same as Moulded Case Stress Same as Moulded Case Stress
Temperature cycling Same Not required for IEC Same Not required for IEC
External Short Circuit Charge:IEC – RTJapan – extremes Test:IEC – 55C and RTJAPAN – 55C Charge:IEC – extremesJAPAN – extremes Test:IEC – RTJAPAN – 55C Charge:IEC – RTJAPAN – extremes Tests:IEC – 55 and RTJAPAN – 20C Charge:IEC – extremesJAPAN – extremes Tests:IEC – 55CJAPAN – 20C
Free Fall Same Same Same Same
Mechanical Shock Same Not required for IEC Same Not required for IEC
Thermal Abuse(cell only) Charge:IEC – RTJAPAN – extremes Same
Crushing of cells(cell only) Charge:IEC – RTJAPAN – extremes Test:IEC – RTJAPAN – extremes Charge:IEC – extremesJAPAN – extremes Test:IEC – RTJAPAN – extremes
Low Pressure Same Not required for IEC    
Overcharge of cells(cell only) Test:IEC – RTJAPAN – extremes Not required for IEC
Forced Discharge(cell only) Test:IEC – RTJAPAN – extremes Test:IEC – RTJAPAN – extremes
Cell protection against high charging rate(cell only) Test:IEC – RTJAPAN – extremes Not required for IEC
Forced internal Short circuit(cell only) Not required for IEC Same
Function of overcharge protection of batteries(battery only)  Not required for IEC  Not required for IEC Not required for IEC Not required for IEC
Free Fall with appliance(battery only)  Not required for IEC  Not required for IEC Not required for IEC Not required for IEC
Other IEC standard requires an overcharge test that is not part of either Japanese standard.

In previous years, an application of IEC 62133:2002 plus JIS-C-8714 requirements would cover all Japanese requirements.  However, the DENAN Law requires testing that is normally part of IEC 62133:2002 to be performed at the extreme temperatures.  This makes the Japanese testing much more extensive at the cell level and removes almost all overlap between the International IEC standards and the DENAN Ordinance.  It is important to understand how the DENAN law will work with existing IEC and CB reports to both first and second edition of IEC 62133.

Japanese Compliance with a First Edition IEC62133 report

By title alone, the overlap between the 2 sets of tests seems extensive with only a handful of testing that would need to additionally be completed.  However, upon further inspection of the latest Revised Ordinance requirements, there is some overlap, but there is an equal amount of additional testing required.  At the cell level the overlap includes only the Vibration, Free Fall, Temperature Cycling, Mechanical Shock and Low Pressure.  If you have a cell that has been tested and shown compliant with IEC62133 First Edition, the test plan for compliance with the DENAN law will be as noted here:

Test Sample count
Continuous Low Rate Charge 5 (Tested at highest temperature)
External Short Circuit 10 (Charge: extremes; Test: 55C)
Thermal Abuse 10 (Charge: extremes)
Crushing of cells 10-20 (Charge: extremes; Test: extremes; narrow side crush for prismatic cells)
Overcharge of cells 10 (Test: extremes)
Forced Discharge 10 (Test: extremes)
Cell protection against high charging rate 10 (Test: extremes)
Forced internal Short circuit 10-20 samples

This will require an additional 75 -95 samples depending on the construction of the cells.

For a battery pack, the overlap from IEC62133:2002 to the DENAN Law will include Vibration, Moulded Case Stress, Temperature Cycling, Free Fall and Mechanical Shock.  If you have a battery that has been tested and shown compliant with IEC62133 First Edition, the test plan for compliance with the DENAN law will be as noted here:

Test Sample Count
External Short Circuit 10 (Charge: extremes; Tests: 20C)
Function of overcharge protection of batteries 1
Free Fall with appliance 3 batteries, 1 host

This only requires an additional 14 samples plus a host device for drop.  The host device does not have to be functional, but it does need to be complete.

Japanese Compliance with a Second Edition IEC62133 report

If you have a compliance report for your battery to Second Edition of IEC62133, the overlap of testing to the DENAN law is minimal and will require a significant amount of testing, particularly at the cell level.  The overlap at the cell level will only include Free Fall, Thermal Abuse and Forced Internal Short Circuit (if this deviation was tested under the IEC62133 testing).  This leaves the following test plan for Japanese compliance for a cell that is compliant with IEC62133:2012:

Test Sample Count
Continuous low rate charging 5 (longer duration and run at temperature)
Vibration 5
Temperature cycling 5
External Short Circuit 10 (Test temperature different)
Mechanical Shock 5
Crushing of cells 10-20 (Test temperature different)
Low Pressure 3
Overcharge of cells 10
Forced Discharge 10-20 (Test temperature different)
Cell protection against high charging rate 10

This will require 73-93 additional cells for testing, and an additional 20 if Forced Internal Short Circuit was not completed as part of the IEC62133:2012 evaluation.

For a battery pack, the overlap from IEC62133:2012 to the DENAN Law will include Moulded Case Stress, and Free Fall.  If you have a battery that has been tested and shown compliant with IEC62133 Second Edition, the test plan for compliance with the DENAN law will be as noted here:

Test Sample Count
Vibration 5
Temperature cycling 5
External Short Circuit 10 (Test temperature different)
Mechanical Shock 5
Function of overcharge protection of batteries(battery only) 1
Free Fall with appliance(battery only) 3 batteries and 1 host

This will require 29 additional batteries and a host device for testing.

As the international arena moves to greater acceptance of the second edition of IEC62133 the amount of testing required for compliance in the Japanese market will need to be considered since it could be extensive.  A copy of the Ordinance and other information about Japanese requirements for Li Ion batteries can be found at the this link.

Energy Assurance can provide you with a quote for testing to include a CB report to IEC62133:2012 as well as the compliance with the DENAN law for your cell or battery pack.

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