The Samsung Galaxy Note7 arrived to great acclaim on 19 August 2016. It was literally the best phablet ever, with its IP68 rating and its improved S Pen and Knox capabilities. However, its massive early success was soon overshadowed by reports of some Note7 phablets catching fire – the infamous exploding battery problem.
In October, Samsung initiated a global replacement program, but even some of the replacement devices continued to catch fire. That’s when they decided to recall and permanently end the sale of the Galaxy Note7. Since then, they have been working hard on finding out what happened, and how to prevent a recurrence.
After an exhaustive investigation, Samsung can now reveal what caused both the original and the replacement Galaxy Note7 phablets to catch fire, and what they are doing to prevent that from ever happening again. Check it out!
After the global replacement program was initiated, Samsung assembled 700 engineers to find out why some of them would spontaneously catch fire. Together with the replacement Note7 phablets from the global recall, their engineers tested more than 200,000 of those returned devices, and over 30,000 batteries.
Samsung also roped in three industrial safety and quality control organisations – UL, Exponent and TÜV Rheinland – to examine the Galaxy Note7 phablets, and provide Samsung with their own findings.
Finally, Samsung went back and examined every aspect of their production processes in their factories in China, Vietnam and south Korea – from hardware and software development to the assembly and testing of the Galaxy Note7, as well as logistics.
The reason why both the original and the replacement Galaxy Note7 phablets exhibited similar spontaneous combustion issues was because two different batteries were catching fire under different circumstances.
The first situation involved battery A which had an overly small casing. The cramped condition led to the negative electrodes being “deflected in the upper right corner of the battery“, and coming into contact with each other.
The second situation involved battery B where welding burrs on the positive electrode penetrated the insulation tape and separator, and came into direct contact with the negative electrode. This essentially resulted in a short circuit.
Making Sure It Won’t Happen Again
To ensure that Samsung users will never have to worry about the exploding battery problem ever again, Samsung developed a rigorous 8-point battery safety check protocol for all future Samsung devices :
- Enhanced battery durability tests – includes overcharging tests, nail puncture tests and extreme temperature stress tests.
- Visual inspection tests of every battery under standardised guidelines and objective criteria.
- X-ray scans of every battery to look for any abnormalities.
- Every battery will undergo a large scale charging and discharging test.
- TVOC (Total Volatile Organic Compound) Test – to make sure there isn’t the slightest possibility of leakage
- Disassembly Test – the batteries are disassembled to assess their quality, including the battery tab welding and insulation tape conditions.
- Accelerated Usage Test – the batteries will undergo extensive tests to simulate accelerated consumer usage scenarios
- △OCV (Delta Open Circuit Voltage) Test – Samsung will check for any change in voltage throughout the manufacturing process, from component level to the assembled device.
Samsung may have been hit hard by the exploding battery problem in the Galaxy Note7, but there may be a silver lining after all. It brought up the critical and often overlooked issue of the safety of lithium-ion batteries that are, by nature, volatile. The new battery safety check protocol Samsung put in place should become an industry-standard. Other smartphone manufacturers would do well to adopt Samsung’s battery safety check protocol, or a similar one.