Samsung has put months of speculation finally to rest by revealing what caused its Galaxy Note 7 smartphones to spontaneously combust. As it turns out, the batteries are to blame.
If you need to brush up on the story, you can get a blow-by-blow account right here.
Suffice to say that the Note 7 was Samsung’s best flagship, it started blowing up, Samsung issued a recall once and replaced devices, the replaced devices also started blowing up, Samsung issued a global recall and canned the Galaxy Note 7.
Speaking to Recode, Samsung revealed that “700 dedicated staff testing 200,000 phones and 30,000 additional batteries” handled the investigation into the Note 7 explosions. Third party firms, including UL, Exponent and TUV Rheinland were brought in to investigate as well.
At the conclusion of testing, it was discovered that there was a flaw in both batteries used by Samsung for the Note 7.
Originally, the Samsung Galaxy Note 7 units that were shipped to the Western markets carried a battery made by Samsung SDI (let’s call this Battery A). The phones shipped to Chinese markets were made by a local Chinese manufacturer (this is Battery B).
When phones with Battery A started blowing up, Samsung issued replacements with Battery B.
The problem with Battery A, apparently, was caused by a manufacturing defect. In many cases, the upper-right corner of the battery could bend easily, sometimes causing negative and positive electrodes to come into contact with each other.
The tip of the negative electrode was also incorrectly located, says Samsung.
This would cause the battery to short circuit and then it would catch fire.
The issues with Battery B apparently popped up when Samsung decided to rush production of Battery B in response to the initial recall.
The rushed production apparently resulted in a welding defect that again caused the battery to short-circuit and explode. It was also discovered that some of the new batteries didn’t have proper insulation.
Essentially, Samsung is saying that the issue with the first batteries was a design flaw and the one with the second batteries was a manufacturing defect.