Samsung Electronics has blamed battery malfunctions for the Galaxy Note 7 catching fire, ending widespread speculations that the explosions were caused by the device’s hardware or software.

Since sales of the fire-prone Note 7 were discontinued in October, there have been several media reports attributing the device’s hardware design to the explosions -- alongside battery faults -- as Samsung excessively squeezed too many parts, such as a bigger battery, waterproof and dustproof features and iris scanner, into the device to beat rival Apple.

However, Koh Dong-jin, Samsung’s mobile business chief, denied the speculation, saying, “We deeply looked into everything from battery, hardware, software algorithm, production to distribution. We found nothing problematic other than the batteries.”

Samsung said the conclusion was made after tests were conducted on 200,000 smartphones and 30,000 batteries by Samsung and three independent testing firms, including US firms UL and Exponent and German company TUV Rheinland.

Koh said the company found out that battery affiliate Samsung SDI had a structural design flaw while Chinese battery maker ATL -- whose clients also include Apple -- had a manufacturing defect.

“(The faulty batteries were made) because we needed higher capacity batteries for the Note 7 with multiple functions, and the battery makers adopted new production methods,” Koh said.


Samsung, however, said it will not hold the two battery makers accountable, even though the Note 7 debacle brought the loss of around 7 trillion won ($5.9 billion).

“We should be responsible for the issue because we proposed the battery specifications for the innovative Note 7 and did not identify the battery design and process (faults) in the final stage,” the mobile chief said.

Separately from Samsung, the investigation result on the Note 7 explosions will be announced by the government this week.

The state-run Korea Testing Laboratory, which set up an advisory group comprising 13 professionals, has been conducting diverse tests including computed tomography, nondestructive inspection and destructive inspection on the exploded Note 7 over the last three months.

The announcement is expected to focus more on future measures rather than causes, as Samsung already announced the battery was the key cause of the explosions.

The world’s largest smartphone maker then vowed to strengthen its safety design standard and boost parts development in partnership with outside experts for its upcoming devices.

Samsung has set up a team specializing in parts within its information technology and mobile communications unit to be responsible for design, verification and the production process of key parts. The company also created an advisory group comprising professors from top universities including Cambridge, Berkeley and Stanford.

By Shin Ji-hye (shinjh@heraldcorp.com)