by Samsung’s Galaxy Note 7 was intended to be the company’s best smartphone to date, but then it started exploding.
Following two recalls and global airline bans, the South Korean tech giant has been pressured to reveal what exactly caused the Note 7 to explode, and what they would do to ensure that it didn’t happen in future devices.
The (Real) Reason Behind The Galaxy Note 7 Exploding
In a livestreamed press conference held in South Korea, Samsung finally unveiled the cause of the explosions. As expected, battery manufacturing related issues were said to be the cause.
The First Batch
The initial batch of Galaxy Note 7 devices that exploded had a battery case manufacturing defect, which caused the negative electrodes in the corner of the battery to bend.
Samsung identified an “additional contributing factor”, however, with the initial batch of handsets / batteries. Namely, that the negative electrodes were too long, which led to them being bent in the curve on the long side of the battery.
Samsung recalled the initial batch of handsets and issued replacements, with batteries made by a completely different manufacturer. The thinking, of course, being that these new handsets would not explode. Unfortunately, they did.
The Second Batch
It turns out that when the manufacturer of the second battery connected the positive tab to the battery, the welding process – which has been called “poorly controlled” – created high, sharp welding burrs.
It’s normal for the battery’s electrodes to expand and contract while charging and discharging. But, due to the manufacturing, this caused the welding burrs to scrape against the insulation between battery layers. Eventually, this scraping penetrated the insulation and shorted out the battery, causing it to explode.
There was yet another “additional contributing factor” to the failure of the second battery. And, this one is far more worrisome than with the first battery: some of the batteries were missing insulation tape. The tape helped reinforce certain trouble spots. And, it appears, that the manufacturer of the second battery forgot to attach it to many units.
Plans To Avoid Explosions In The Future
So, what’s Samsung doing to ensure this doesn’t happen again?
The company announced an eight point battery safety check process, which includes the same techniques that helped solve the Note 7 battery defects.
Samsung says that it has “reassessed every step of the smartphone manufacturing process”. The company has also “formed a Battery Advisory Group of external advisers, and academic and research experts to ensure it maintains a clear and objective perspective on battery safety and innovation”.
Samsung has also said that the product planning stage has changed. This now includes an “improved battery design safety standard”, “brackets around the battery for protection”, as well as “improved algorithms” for governing the battery promised in future devices.
