Traveling With A Portable Power Bank? Here’s Why You May Want To Think Twice.

Though they’re a staple in most travelers’ carry-ons for keeping phones, tablets and other devices charged on long flights, recent incidents have put power banks under the spotlight.

With increasing reports of lithium-ion battery mishaps, airlines and safety experts are tightening the rules around their use. So, before you pack your power bank, here’s what you need to know to stay safe while traveling.

Following a January fire aboard an Air Busan flight that was believed to have been caused by the lithium battery in a portable power bank, airlines are revising their rules around these devices.

While passengers are still allowed to bring them on board, some carriers, including Singapore Airlines, EVA Air and Thai Airways, are restricting their use during flights. Others, such as Asiana Airlines, Cathay Pacific and Korean Air, are taking it a step further by requiring passengers to store power banks in their carry-on bags either in the seat pocket or under the seat in front of them, rather than in the overhead compartments.

When it comes to powering our everyday devices, lithium-ion batteries have a clear advantage over other battery chemistries.

“Lithium-ion batteries provide higher energy in small capacities, as well as the ability to charge devices at a quicker rate, making them an ideal source for power in laptops, phones, power banks and other common items found on travelers’ packing lists,” said David Klanecky, CEO and president of Cirba Solutions, a leader in lithium battery recycling.

He also points out that these batteries are hidden in more travel items than most people realize, including smartwatches, carry-on luggage with built-in chargers, electric toothbrushes, gaming consoles and even kids’ toys. With their compact size, lightweight design and ability to deliver consistent power, it’s easy to see why lithium-ion is so popular. Plus, they’re rechargeable and built to last, so you can keep using them without the hassle of frequent replacements.

Overcharging, overheating or even hidden manufacturing flaws can trigger a dangerous chain reaction in a lithium-ion battery known as thermal runaway, causing its internal temperature to rise.

“Thermal runaway is a phenomenon in which high temperatures increase the rate of chemical reactions, which further increase the temperature,” explained Benjamin Lee, a professor at Penn Engineering. As the battery heats up, these internal chemical reactions intensify, leading to a short circuit that breaks down the materials inside.

“When the metal oxides in a battery’s electrode are heated, they decompose and release oxygen gas,” said Lee, who added that this process in turn releases more heat. “This vicious feedback loop is one of the primary causes of battery fires or explosions,” he noted, also pointing out that physical damage to the battery, such as water damage or crushing, can create short circuits.

While conventional and battery fires rely on the same three elements of heat, fuel and oxygen to burn, the kicker is that a lithium-ion battery can generate oxygen on its own, making it significantly more dangerous.

“The chemistries behind lithium-ion batteries can produce oxygen and fuel fires,” Lee said. “This oxygen could sustain a fire and complicate firefighting strategies. Smothering a fire to eliminate its oxygen supply would not work for a lithium-ion fire.” In a typical fire, cutting off the oxygen supply, like placing a lid on a grease fire, can help snuff it out. But a battery fire, especially mid-air, calls for more specialized tactics.

Airline agents routinely ask whether you’ve packed any portable batteries, like laptop batteries or power banks, in your checked luggage, and there’s a good reason.

“During air travel, passengers carrying devices powered by lithium-ion batteries are asked to place them in carry-on bags so if the battery does go into thermal runaway, staff onboard can quickly detect an issue and take action immediately,” Klanecky said. “If a battery is damaged or becomes damaged during transport and goes into thermal runaway in the cargo hold, it most likely will go undetected until it’s too late, putting everyone at risk.”

Klanecky also notes there’s a good reason flight attendants ask you not to retrieve your phone yourself if it slips between the seats: “If a passenger reaches for the phone, there is a higher risk that the phone, including the battery, could crack or become damaged, increasing the risk of thermal runaway when pulling the phone from the tight crevices between the airplane seats.”

In addition to keeping your devices and portable batteries in your carry-on during flights, experts agree it’s just as important to steer clear of using damaged devices or batteries, as they’re far more likely to short-circuit or trigger thermal runaway. “Batteries often give off warning signs that indicate that they are unsafe to use,” explained Evan Jones, a communications representative at Electrical Safety Foundation International. “Batteries that are swelling or bulging, emitting odd odors or sounds, or leaking should be discarded immediately at a designated battery drop-off site. If a battery emits excessive heat or loses its charge quickly or while not in use, this also suggests that it is not safe for use.”

The seemingly growing number of lithium-ion battery incidents may also be partly due to a rise in counterfeit or untested products, often bought from untrustworthy marketplaces. “Many consumers are not aware of the risks of uncertified and untested products or don’t believe that an incident could happen to them,” Jones said. These off-brand power banks often skip critical safety features like temperature regulation, overcharge prevention or short-circuit protection, and may use low-quality materials that are more likely to fail.

When shopping for your next power bank, there are a few key things to remember. “Always make sure to purchase batteries that are listed by nationally recognized testing laboratories, like UL and CSA, and sold by reputable retailers. Also, be aware of potential recalls for devices you own,” Jones advised.

If your lithium-ion battery is no longer safe to use, dispose of it properly at a designated drop-off site. “Many large brick-and-mortar electronics retailers accept lithium-ion batteries and e-waste for disposal,” Jones said. “Lithium-ion batteries should never be disposed of in household trash or recycling, as they can, and frequently do, cause fires during transport and at waste management facilities.”