When Apple decided to eliminate removeable batteries from their phones and computers, who would have guessed it might eventually impact airline safety? With the increase usage of our phones and the need to recharge more often, an entirely new industry of power banks emerged, and those batteries have become the major cause of serious airline fires and air emergencies.
Apple’s iPhone popularized the idea that batteries should be sealed inside sleek, ultrathin devices. Nearly every smartphone manufacturer followed, making it difficult or impossible for consumers to inspect or replace aging batteries. While sealed designs enable thinner, more water-resistant products, they also mean damaged or deteriorating batteries often remain in service longer than they otherwise would.
Airlines now consider lithium battery fires one of the fastest-growing risks in commercial aviation. In the United States, battery-related incidents have more than doubled since 2019, and this year will hit a new high. Globally, airlines are banning power banks from overhead bins, restricting their use during flights and retraining cabin crews to respond to battery fires.
Earlier this year an Alaska Airlines flight returned to Wichita after a passenger’s phone and power bank burst into flames shortly after takeoff. Similar incidents have forced emergency landings in Europe, Asia and the United States. Last year, an Air Busan aircraft was destroyed after a power bank ignited in an overhead compartment, injuring 27 people.
The cause is known as thermal runaway. When a lithium-ion battery is damaged, poorly manufactured, overcharged or internally short-circuited, it can rapidly generate heat until it ignites. Once one battery cell catches fire, neighboring cells often follow, creating an blaze that’s difficult to extinguish.
Having spent years developing consumer electronics in China, none of this surprises me. One of the lessons I learned is that the quality of a finished product is only as good as the weakest step in its manufacturing process. A single assembly worker who forgets to tighten a screw or one solder joint that isn’t quite right is all it takes. An increasing number of these products from no-name brands use battery packs sourced from second-tier suppliers instead of a top-tier manufacturer.
Most factories are good at quality control. But when you’re producing millions of battery-powered devices, even an exceptionally low defect rate still leaves thousands of defective products. And in rare cases a defective lithium battery may not just stop working but catch fire. And even the top brands , such as Anker, occasionaly have had to recall their battery packs.
Many of the less costly battery packs take design shortcuts to save a few cents. They may omit protective circuitry, use lower-grade battery cells or skip quality-control testing altogether.
Counterfeit batteries are another growing problem. They may look identical to the original but have none of the engineering safeguards designed to prevent thermal runaway.
As an airline passenger we now board with four or five battery-powered devices. That means a single wide-body aircraft may contain more than 2,000 lithium-ion batteries, an extraordinary concentration of stored energy flying at 35,000 feet.
What can we do? Buy power banks and replaceable batteries from reputable manufacturers like Anker, Belkin, UGreen and others. Avoid inexpensive power banks from unknown brands. And pay attention to the temperature of the device or power bank while charging. It may get warm but should never be too hot to hold. If that occurs while on a flight, call a flight attendant who now carries special bags to contain a possibly defective battery.
As someone who has shepherded products from the design through manufacturing in China and other countries in Asia, I’ve learned that quality is determined by thousands of tiny manufacturing and assembly steps often performed by lower-paid workers. I’ve also learned that a product design decision that Apple made twenty years earlier can have unintended consequences that few could have predicted.
