A few months after Samsung was forced to recall and later cease production of the Galaxy Note 7, the Korean conglomerate has now revealed the results of its investigation regarding its exploding devices.
The investigating groups, one from Samsung and three from third party firms (Exponent, TUV Rheinland, and UL), came up with two reasons.
Design Flaw
The first involved a design flaw in the original Galaxy Note 7 batteries. The said flaw, located at the upper right corner of the battery, allowed the electrodes to bend causing the separation between the negative and positive tabs to breakdown.
This is similar to what one independent company, Instrumental, discovered upon subjecting the device to a teardown. Instrumental found out that the separators between the negative (graphite) and positive (lithium cobalt oxide) layers were too thin to prevent the layers from touching each other.
Manufacturing Issues
A manufacturing issue on the ramp of the replacement batteries was the reason why they also caught fire. Other problems in manufacturing that the investigators encountered were the battery's high energy density, inconsistencies in the charge level, and missing or uneven insulation tape.
Interestingly, Samsung pointed out that the problem was not the phone itself. The Galaxy Note 7, on its own, was fine but it demanded too much. It required powerful batteries in its thin frame which unfortunately pushed the limits of engineering.
The investigating team included around 700 engineers who focused on testing 200,000 units of the Galaxy Note 7 along with 30,000 more batteries.
The Galaxy Note 7 was released in August last year but after hundreds of cases wherein the handset suddenly went up in smoke and even caught fire, Samsung recalled the devices and had the batteries replaced. But even the replacement batteries were defective and caught fire, as well. There even came a point when the flagship phablet was banned from all U.S. flights. Numerous theories surfaced as to what may have caused the explosions but most trained their focus on the batteries. It was later discovered that Samsung tested its batteries in its own lab, something that is not practiced by other companies. The norm was to have a third party test the batteries. Samsung finally pulled the plug on the Galaxy Note 7 and began its month's long investigation on the matter.
Samsung's head of the mobile division, DJ Koh, offered a sincere apology for the company's shortcomings and is hopeful that it can regain the trust of its customers, distribution partners, retailers, and carriers.
According to Recode, Samsung is planning to continue the Galaxy Note line but will pay more attention to product safety.
