Samsung Reveals Official Cause Behind Galaxy Note 7 Battery Explosions

Samsung Discloses Reasons for Galaxy Note 7 Fires

In 2016, Samsung faced one of its most challenging periods with the Galaxy Note 7 flagship smartphone. The device was recalled twice after multiple incidents of batteries catching fire, ultimately leading the company to discontinue the model altogether. The recalls cost Samsung approximately $3 billion and damaged consumer trust worldwide.

During a live streamed press event, Samsung revealed the official findings of its extensive investigation. The sole cause of the Note 7 failures was defective batteries, with no issues found in the phone's hardware, software, or design. Two different battery suppliers provided cells for the device, and both produced flawed units that led to the same dangerous outcomes.

The first battery version, referred to as Battery A, had a design flaw where the casing was too small to safely contain the electrode assembly. This poor fit created a risk of short circuits. The second replacement battery, Battery B, suffered from manufacturing errors related to ultrasonic welding of the electrode tabs, which caused insulation failure and short circuits. In some cases, insufficient insulation between electrodes was also identified.

Samsung conducted a rigorous 120-day investigation involving a dedicated test lab with 700 researchers, 200,000 devices, and 30,000 batteries. The company performed thousands of tests under various real-world conditions, examining wired and wireless charging, water resistance, USB-C charging, the Iris Scanner, software algorithms, and third-party app impacts. Samsung also collaborated with three independent testing labs—UL, Exponent, and TUVRheinland—who examined software, hardware, manufacturing, logistics, and handling. All parties concluded that battery defects were solely responsible for the incidents.

To prevent similar issues in the future, Samsung has established a dedicated battery advisory group and introduced comprehensive changes to its internal processes. The company now assigns specific teams to oversee critical final inspections of core components and subjects batteries to an eight-point testing procedure. This includes visual inspections, x-ray examinations, and full disassembly to ensure safety before any device reaches consumers.