The higher battery density of the Galaxy Note 7 compared to its predecessor was not the root cause of the phones catching fire, according to Samsung Electronics' mobile boss DJ Koh.
The Note 7 had a 3,500 mAh battery, 500 mAh higher than the Galaxy Note 5, raising speculation whether the higher density had anything to do with the phones catching fire.
Samsung announced that faulty batteries were to blame for the Note 7 fires last year and promised to apply a new eight-step inspection process for future models.
President DJ Koh said the firm looked into the higher capacity also, but found no direct link with energy density and the fires during the investigations. The battery's structural problem and manufacturing problems were the main cause, he said. UL's Sajeev Jesudas, also at the conference, reiterated that energy density was unrelated to the fires.
Software, safe phone, and battery design are being applied to the Galaxy S8, which will be not unveiled at the Mobile World Congress next month but a later date, Koh said.
The design of the Note 7 itself was also not to blame, Koh said. "There were many opinions on what caused the fires: the strengthened water- and dust- proof feature that prevented heat from dissipating; problems with the protective circuit around the battery, power controller, and software algorithm. But our internal investigation found no problem with the Note 7's design and this has been approved by outside agencies and those in academia," said the president.
"We even tested without the back cover. We tested while the battery was loosely attached. We tested the battery by itself. We can officially announce that our results [that the model itself was not at faulty] after seeing the same ratio of fires from the batteries," he said.