This is why Samsung Galaxy Note 7 batteries were exploding

Last year Samsung Galaxy Note 7 owners found themselves equipped with a pocket-sized bomb thanks to a major battery malfunction in their handsets. Many phones have battery issues but, with the Note 7, Samsung’s battery problem was monolithic – affecting 112 phones within the first month of being on sale, and costing the company $5.3 billion.

After Samsung recalled its Note 7 phones, it began an investigation into how its batteries all started to malfunction. The results, which were revealed during a press conference in Seoul on Sunday, revealed that it was a combination of design and manufacturing flaws that led to creating pocket-sized explosives.

During Samsung’s investigation, it tasked more than 700 R&D engineers to replicate the Note 7 failures, testing more than 200,000 Note 7s and 30,000 individual batteries. According to its investigation, which was also independently verified by Germany’s TUV Rheinland, the battery manufacturing and design fault is a result of the two suppliers it uses for its batteries.

Samsung refused to identify the companies, although The Wall Street Journal alleges that Samsung SDI (a wholly owned Samsung company) and Chinese supplier ATL are to blame.

You may be wondering exactly how Samsung could let something like this happen, but it transpires that the South Korean electronics manufacturer has little say on battery specification beyond dictating basic battery requirements (energy capacity, voltages, currents, dimensions and so on). This means that battery manufacturers have leeway in how they design and build their batteries, resulting in two different types of battery – and two distinct problems – for the Galaxy Note 7.

https://youtube.com/watch?v=OeKdcIOAEL8

Samsung discovered that “Battery A” had a design flaw that saw the battery manufacturer not providing enough space in the battery pouch for its electrodes to remain straight. Bent electrodes meant undue stress on the battery’s internal separators, resulting in a failure.

“Battery B”, however, had a manufacturing defect related to an “abnormal welding process”, resulting in an improper contact between the device’s positive tab and the negative electrode. Independent testing firms also discovered that Battery B was supposed to have insulation tape covering the weld; in some instances, this tape was missing.

Because of the two separate battery issues, Samsung had to issue two separate recalls. The report notes that Samsung believed that once it had recalled Battery A phones, it thought those equipped with Battery B would be safe. However, after Battery B defaults surfaced, Samsung released its secondary supplier couldn’t safely manufacture batteries at the scale needed.

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Samsung may have placed the blame on its suppliers for the Note 7’s battery failures, but it isn’t absolving itself of fault. “Ultimately we take responsibility for this,” said Samsung Electronics America senior vice president Justin Denison, speaking to USA Today. “It’s our product, we set the specifications… and it’s up to us to catch the problem before it leaves in one of our devices.”

Off the back of Samsung’s investigation, it has now implemented an eight-point battery safety check that includes a durability test, visual inspection, X-ray test and other tests to ensure the reliability of each battery. However, Samsung has also said it isn’t changing its battery suppliers for upcoming phones such as the Samsung Galaxy S8.

Moving forward, Samsung plans to run an advertising campaign to show its commitment to quality and assurance. It’s also reaching out to loyal Note customers to communicate what happened with the Note 7 and ease fears about any future releases.

Hopefully Samsung can repair its public image in time to ensure the Samsung Galaxy S8 launch isn’t dogged with fears around battery reliability.

Below is an infographic detailing Samsung’s findings on the Galaxy Note 7 battery faults.