WASHINGTON -- It was overheating Samsung Galaxy Note 7 incidents thatand months-long investigation by 700 Samsung engineers.
Over 200,000 devices and more than 30,000 lithium-ion batteries were tested.
Samsung found that a design defect -- incorrect battery positioning in the Galaxy Note 7’s upper right corner --caused the first wave of problems.
Then some replacement devices had a manufacturing error; An abnormal weld that led to internal short circuits.
“Two different defects in two different sets of batteries from two different suppliers, but you end up with the same result in both cases, which is what seems so unbelievable about this case,” said Dan Ackerman, an editor for CNET.
In the U.S., Samsung says it received 13 reports of burns, 47 of property damage and, in all, 96 reports of overheating batteries.
The vast majority of rechargable electronic devices are powered by lithium-ion batteries, known for their high power output and low cost.
“Conceptually these batteries are safe, but we’re asking them to do more than ever in more tightly constrained and designed products,” Ackerman said. “So you’re really pushing the boundaries there of what these batteries can physically do.”
There have also been other products like e-cigarettes overheating and catching fire, and about a half million hover boards were recalled last summer because faulty battery packs could overheat and in some cases catch fire.
Airlines including Alaska and Virgin America are nowthat can contain a lithium ion fire.
Samsung also announced a new eight-point safety check of batteries that includes x-raying for abnormalities.
Of the 3 million Note 7s sold, 96 percent have been returned. That leaves about 120,000 unaccounted for worldwide.