The message on Twitter had the ominous overtones of recent Samsung problems, when Twitter user Bree posted a video of her swollen and blistered iPhone 7 Plus with smoke seeping out around the edges. This wasn’t the first time that an iPhone 7 fire had been reported, but this was the first video of the incident to show up on social media. Previously, scattered reports of burning and exploding iPhone 7 devices had been reported, but none seemed to have public evidence.
As you might expect, the viral nature of the Twitter posting caught Apple’s attention. The company replaced the iPhone and collected the burned one to investigate. The incident happened on Feb. 22, so at this point, Apple hasn’t had time to do a full investigation.
But that wasn’t the only incident of an iPhone 7 catching fire. Last fall, an Australian surfing instructor reported that his iPhone had caught on fire and destroyed his car. Last September, a report on Reddit indicated that an iPhone 7 caught fire while being shipped to a customer.
Older iPhones are also having issues, although they’re a little less dramatic. iPhone 6 and 6 Plus phones have had an ongoing problem of the battery power suddenly dropping to zero even when it had been fully charged a few minutes prior to the event. After several months of investigation, Apple released a software fix in the form of iOS 10.2.1, which according to Apple, solved about 80 percent of the problems.
The source of these incidents appears to be related to safety circuitry that was intended to keep iPhone 6 batteries from overheating and burning. The sudden drop in power was related to a routine in iOS that was supposed to sense when there was a problem with the battery and then turn the phone off to protect it. The problem in this case was that the software reacted even in the absence of a battery fault.
Both of the iPhones with battery problems seem to be rooted in the Lithium-Ion batteries that power them. When a battery is damaged, causing internal separators to be breached, the battery can discharge suddenly, causing significant heat and frequently even an explosion. The iPhone battery fire in September appeared to be the result of damage while the phone was being shipped, causing a fire.
The cause of the other two iPhone 7 battery fires hasn’t been determined. But in the case of the iPhone belonging to Bree, the phone was simply sitting on a table when it spontaneously caught fire.