Gov't confirms Note 7 probe findings

By Yoon Sung-won

The government said batteries, not the handset, were the root cause of Galaxy Note 7’s fire problems, sharing its view with Samsung Electronics.

In its report, the Korean Agency for Technology and Standards (KATS) under the Ministry of Trade, Industry and Energy also pledged to tighten regulations to boost the safety of smartphone batteries.

“Through the testing of the recalled handsets, we have discovered factors and a flawed manufacturing process that are highly likely to cause batteries to catch fire,” the agency said, Monday. “But we have not found anything significant from the handset.”

As fires continued to be reported even from replacement handsets with new batteries after the first recall last Sept. 19, KATS had suggested Samsung Electronics stop selling the handset. Later on Oct. 19, the agency started an official government investigation through the Korea Testing Laboratory (KTL), independent from the fact-finding by Samsung Electronics.

Some of the batteries had projecting swellings on the anode tab, which might have caused a short circuit within the cell. The investigation also revealed some of the swollen batteries did not have insulating tape to prevent short circuit.

“Faulty manufacturing processes which have resulted in protruding swellings on the anode tab and poor attachment of insulating tape are highly likely to be the cause,” KATS said. “The KTL has also looked into possible root causes of the fires such as the handset’s power control or battery protection circuit, external pressure and lack of space for the embedded battery cell. But it could not find any abnormalities.”

Samsung SDI and China’s Amperex Technology (ATL) supplied the batteries for the Note 7. Much like Samsung Electronics’ Jan. 23 report, KTL’s investigation showed Samsung SDI’s batteries had anode and cathode tabs on the upper right corner that were crushed and curled up together to cause an internal short circuit, while those of ATL had swellings on anode tabs.

The KTL has collected and examined samples including 14 burned Note 7s, 46 unburned ones and 169 batteries as well as two sets of extremely swollen handsets and batteries from Samsung Electronics. The sample size, however, was significantly smaller compared to that in Samsung Electronics’ own investigation. Earlier on Jan. 23, Samsung Electronics said it looked into more than 200,000 Note 7s and 30,000 batteries.

“Tests on a massive number of smartphones and batteries would have been helpful in verifying our assumption on the cause of the fire problem,” KATS said. “But the government and the accident investigation center had limits for doing so.”

The government said smartphone batteries with new designs and technologies must be tested by KATS every two years for safety control.

“The accidents could have been prevented if the battery manufacturers and end-product provider strengthened process and quality control,” the KATS said. “To prevent recurrence of such incidents, we will improve policies to check for flaws in the battery manufacturing processes, encourage safety monitoring of smartphone makers and boost recall systems and safety investigations of products with batteries.”

So far, batteries have been tested for safety only before mass production. KATS plans to revise regulations by October to include smartphone batteries to be regularly tested for the next five years.