Samsung Galaxy Note 7 explosions were caused by two set of faulty batteries

Samsung has also announced a new 8-point battery safety check and multi-layer safety measure to ensure this does not happen again.


After months of investigation, Samsung has finally concluded its probe into the Galaxy Note 7 battery fiasco. Samsung has also published results of its findings to reveal the culprit that caused the smartphone batteries to overheat and catch fire. According to Samsung’s own investigation and three independent industry organizations, the overheating problem in was caused by two separate problems in batteries that were sourced from two different suppliers.

Samsung launched the Galaxy Note 7 in August last year, and soon after its release, multiple reports about the smartphone catching fire and exploding started to emerge. In September 2016, the company had to halt the production and replace the faulty batteries. Even when that didn’t work, Samsung had to take a tough decision to withdraw the Galaxy Note 7 completely to avoid further damage. The company has mentioned that 96 percent of all Galaxy Note 7 units that were shipped have already been returned.

samsung galaxy note 7 battery design

The fault in Samsung Galaxy Note 7 batteries

Samsung has mentioned that around 700 engineers tested more than 20,000 devices and over 30,000 batteries to get to the root of the problem. Indeed, short circuit in a battery caused the issue. The damage to the separator allowed the positive and negative electrodes to meet within the jellyroll and cause short circuit. However, there were separate factors that caused the issue in the initial lot and replaced batteries.

samsung galaxy note 7 first battery issue

In the first lot of batteries, it was a design error that caused the batteries to overheat and explode. There wasn’t enough room between the internals and protective pouch around the batteries. The negative electrodes in the upper­-right corner of the battery were deflected. Also, the tips of negative electrodes were incorrectly located in the curve, and not in the planar area where they were supposed to be. ALSO READ: Samsung Galaxy S8 rumor roundup

samsung galaxy note 7 second battery issue

In the second lot, the high welding burrs on the positive electrodes inflated, resulting in penetration of separator and insulation tape which caused direct contact between the positive and negative electrode. To make matters worse, Samsung found that a number of batteries were missing the insulation tape, which made it easier to cause short circuit, catch fire and explode.

Safety check measures to avoid the fiasco

Learning from the Galaxy Note 7 fiasco and withcommitment to safety, Samsung has developed strict quality assurance protocols to ensure the same isn’t repeated. The first is an 8-point battery safety check which will addresssafety of batteries right from component level to their assembly and shipment of devices. ALSO READ: Samsung Galaxy S8 renders show a fourth button, possibly for Bixby digital assistant

The company will be conducting a durability test, which includes overcharging test, nail puncture test and extreme temperature stress test. Next is a visual inspection to ensure each battery is manufactured as per the guidelines and objective criteria. Then comes the X-Ray test to look for abnormalities inside the batteries. Samsung will also be conducting a large scale charge and discharge test.

samsung 8-point battery test

Next is a Total Volatile Organic Compound (TVOC) test to ensure that there is not even a slightest possibility of leakage of volatile organic compounds. Then there is Delta Open Circuit Voltage (OCV) test to look for changes in voltage throughout the manufacturing process. There is also accelerated usage test to replicate multiple customer usage scenarios. And lastly, there is disassembling test to access the battery quality. This test will involve checking of insulation tape and battery tab welding.

samsung multi layer safety

Samsung has also enhanced its multi-layer safety measures protocol to strictly check for safety standards of every element of the company’s devices. This includes the design and hardware strength capabilities, overall product design and materials used in the manufacturing. For safer battery charging temperature, duration and ensuring apt current, Samsung has also improved its software algorithms.

With all these measures in place, we hope the Galaxy Note 7 battery fiasco doesn’t repeat again. Also, it’s not just about Samsung, but we hope all manufacturers take similar safety measure protocols to avoid such problems.

  • Published Date: January 23, 2017 10:36 AM IST
  • Updated Date: January 23, 2017 12:03 PM IST