To safeguard against future issues, Samsung has implemented an 8-point Battery Safety Check Test, which “involves putting our batteries through extreme testing, inside and out, followed by careful inspection by X-ray and the human eye.” The extensive tests will be performed before all new devices that ship in an effort to create a new standard for battery safety.
The story behind the story: Customers have been waiting for an explanation ever since the first Note7 handsets began catching fire in September, and now Samsung needs to follow through on its promises. Now that the company has pinpointed the cause, it needs to assure customers that its safety measures are more than just words. Only by putting consumers’ well-being ahead of competitive ship dates and battles over thinness can Samsung regain the trust it has lost.
As Samsung mobile chief DJ Koh detailed in a press conference, there were actually two separate flaws that caused the handsets to overheat, each affecting different sets of shipments. According to the company, the first batch of phones included an issue related to deficiencies in the heat-sealed protective pouch in the upper-right corner of the battery, which caused the positive-negative electrodes to touch and consequently short circuit. After the first recall, a second flaw in the new battery caused by welding defects and missing insulation tape resulted in similar overheating.
The new tests are designed to insure such flaws never arise again. It starts with a durability test that runs the batteries through several stress tests that subject them to overcharging, puncturing, and extreme temperatures. The test continues with a visual inspection, and moves onto an X-ray for each battery to check for internal abnormalities. Then, Samsung runs a large-scale charge and discharge test, followed by a Total Volatile Organic Compound Test to check for leaks. Samsung continues its testing by randomly disassembling batteries to assess build and component quality and running them through an accelerated usage test designed to simulate two weeks of continuous use. Finally, a Delta Open Circuit Voltage test will monitor the batteries for any voltage spikes through the manufacturing process.
Additionally, Samsung is rolling out improved training programs for everyone involved in the handling of batteries and dedicating teams to handle each core component of the device. It has also commissioned a battery advisory group of experts from the University of Cambridge, UC Berkeley, and Stanford University “to ensure the company maintains a clear and objective perspective on battery safety and innovation.”
Along with the extensive battery checks, Samsung is also implementing multi-layer safety measures during the design stage on other components of its devices—including design, materials, and software—to make sure the system doesn’t put any undue strain on the battery. For example, the company revealed that future smartphone designs will add more space around the battery to accommodate a new bracket design to protect the battery against physical force when dropped, while improved software will offer protection against fluctuation that could have an impact on the core temperature.
Koh said he hopes the issue will serve as an opportunity to improve the safety of Lithium-ion batteries, and said he is exploring ways to share the company's new testing with the rest of the industry. Samsung has been dealing with the fallout from a spate of Note7 fires and explosions for months, with the FAA only recently deciding to lift the requirement for airlines to announce the ban before all flights.
To isolate the cause of the fires, Samsung built a large-scale charge/discharge test facility to complete a detailed analysis of not just the battery, but the entire system. It found that the battery was solely to blame for the issue, and the fast-charging system, water resistance, and USB-C port were all functioning normally.
In its extensive testing, the company commissioned 700 researchers and engineers, and tested some 200,000 fully assembled devices and 30,000 batteries subjected to repeated charge/discharge testing. Its own research was corroborated by independent testing from UL, Exponent, and TUV Rheinland, all of which came to the same conclusions. In his remarks, Koh reiterated that Samsung has seen some 96 percent of Note7s returned out of about 3,000,000 which were activated.