Samsung Electronics Co. Ltd. concluded that irregularly sized batteries and manufacturing problems caused the fires among its Galaxy Note 7 smartphones, The Wall Street Journal reported Jan. 20, citing people familiar with the matter.
The results of Samsung's investigation, in partnership with three quality-control and supply-chain analysis experts, are expected to be released on Jan. 23.
According to the report, Galaxy Note 7 batteries came from Samsung unit Samsung SDI Co. and Hong Kong's Amperex Technology Ltd., with the latter manufacturing its batteries in China. The investigation reportedly revealed that Samsung SDI's batteries did not properly fit into the phones, while those from ATL malfunctioned due to an unspecified manufacturing issue caused by the surge in demand for replacement phones.
U.S.-based UL LLC and Exponent Inc. were reportedly enlisted to study the batteries, while Germany's TUV Rheinland scrutinized supply-chain issues.
Samsung also presented government and regulatory officials in Washington, D.C. with an eight-step process to avoid similar incidents in the future, according to the report.
The South Korean phone maker recalled its Galaxy Note 7 smartphones in September 2016, followed by the cease in production of all units a month later.
Samsung is a unit of the Samsung Group.