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4 Things to Know about Portable Battery Packs in Japan


Portable battery packs are essential for a quick charge of your smartphone or other mobile device on-the-go, thanks to their high capacity, light weight, and wide availability. However, as the number of portable battery packs increases, accidents caused by fire from defective batteries have also been reported. These include fires sparked inside a backpack, in a bedroom while the user slept, and even on a moving bullet train and other public transportation, causing further damage. To prevent such accidents, consumers should be careful when selecting and using portable battery products.

Defective batteries caused 148 accidents over five years

Between FY2013 and FY2017, as many as 148 accidents occurred due to defective portable batteries. During this period, accidents increased from 11 in FY2013 to 41 in FY2017, a dramatic four-fold increase. Among these 148 accidents, approximately 70% were associated with fire.

Certified portable batteries should display a “PSE mark”

Under the Electrical Appliances and Materials Safety Act (PSE Act),all portable batteries must be  affixed with a PSE mark for sale in the Japanese market from February 2019. Before you purchase any portable battery product in Japan, check to make sure it’s labeled with the PSE mark.

Always handle portable batteries with care

Before using any portable battery, read the instruction handbook and make sure to protect batteries from external shocks, such as impacts from hitting or dropping. If the battery becomes extremely hot while charging, or if the battery pack expands or deforms, you should stop using the product immediately, since these conditions may lead to accidents. Furthermore, if you own a battery subject to recall, you should immediately stop using it and contact the appropriate office for the recall, even if your product seems to have no defect. Japan’s Ministry of Economy, Trade and Industry (METI) recommends that all portable battery users periodically confirm whether or not their products are subject to any recall.

A note of caution to businesses

Selling portable batteries without a PSE mark, which is affixed by manufactures or importers to products that comply to Japanese technical standards, is prohibited in Japan. Importers, distributors and other businesses who intend to sell portable batteries in Japan are required to confirm their compliance with the PSE Act.

Last updated:2019-04-25