14 DAY TRIAL // During a press conference held in Seoul, South Korea, Samsung’s President of Mobile Communications Business, DJ Koh, finally revealed the results of the company’s investigation into the Galaxy Note 7. Mr. Koh apologized and thanked customers, mobile operators, retail and distribution partners and business partners for their patience and support.
But Samsung wasn’t the only one to present findings, as three executives from UL, Exponent and TUV Rheinland also presented the results of their own investigation.
“Today, more than ever, we are committed to earning the trust of our customers through innovation that redefines what is possible in safety, and as a gateway to unlimited possibilities and incredible new experiences,” Mr. Koh said.
During the investigation, Samsung examined every aspect of the Galaxy Note 7, including hardware and software during the past few months. The investigations carried out at Samsung and the three independent industry organizations concluded that batteries were to blame for the Note 7’s demise. To explain this, the South Korean company posted an infographic with “Battery A” and “Battery B” samples. The names of Samsung SDI or Amperex weren’t actually mentioned.
Two separate battery problems caused Note 7 units to catch fire
Galaxy Note 7 phones caught fire because there was damage to the separator that keeps positive and negative electrodes from meeting inside the jellyroll. Battery A from the first recall was affected by a defect that caused negative electrodes to be deflected in the upper-right corner of the battery.
It seems that the phone’s design did contribute to this and that the battery manufacturer didn’t adapt its tests to the phone’s specifications. In addition, the tip of the negative electrode was incorrectly located in the curve, and not in the planar area.
Battery B’s main cause was a bit different, as Samsung found high welding burrs on the positive electrode which resulted in the penetration of the insulation tape and separator which then allowed the positive tab to meet with the negative electrode.
A contributing factor was the fact that many batteries were missing insulation tape, which is quite worrying. The reports of third-party labs concluded that the battery was the main cause of Note 7’s demise. Even though Samsung isn’t directly blamed for the Note 7 incidents, the company could have conducted more thorough tests, especially for returned units.
