SEOUL, SOUTH KOREA — The U.S. Federal Aviation Administration has advised passengers not to turn on or charge Samsung Galaxy Note 7 smartphones on aircraft, after faulty battery packs caused some of the phones to explode while charging. <br /> <br />Due to the battery crisis, Samsung was forced to recall 2.5 million units of the Galaxy Note 7, its new flagship phablet. <br /> <br />The faulty battery packs were made by Samsung SDI, a subsidiary of Samsung. Samsung has indicated it will no longer use Samsung SDI batteries in the Note 7. <br /> <br />According to the Wall Street Journal, roughly 65 percent of Galaxy Note 7 batteries were made by Samsung SDI. Thirty-five percent were made by Chinese company Amperex Technology Limited, or ATL. <br /> <br />The Samsung SDI batteries in the Note 7 were found to have faulty separators, which allow the two electrodes to touch. This redirects energy to chemicals called electrolytes, which help to conduct the current. <br /> <br />When the battery is hot, the electrolytes react with other chemicals to release gas in a feedback loop called “thermal runaway,” which can lead to a fire.
