photo by: Contributed

A flyer from the National Fire Protection Association.

With high-tech holiday gifts like new phones, hoverboards and electric bicycles comes a danger that many people don’t think about — fires, explosions and the release of toxic chemicals from those gadgets’ lithium-ion batteries.

These rechargeable batteries are generally safe as long as you follow the manufacturer’s recommendations on how to store and charge them properly. But it only takes a moment for them to threaten your home and your life with fire and poisons if something goes wrong, said Brian O’Connor, senior engineer at the National Fire Protection Association.

“The main component that makes it flammable is hydrogen gas, just like the Hindenburg, but it produces a cocktail of dozens of other flammable gases. Honestly, it’s typically described as a cocktail of flammable and toxic gases, because there’s just dozens of both of those,” O’Connor said.

Here’s what you need to know about these types of fires and how to keep yourself and your family safe:

Anatomy of a battery fire

There are several types of batteries that consumers may bring into their homes. Small, single-use batteries, like the AA batteries used in some TV remotes, are relatively safe because once they are dead, there isn’t any energy left in them to discharge.

But rechargeable lithium-ion batteries found in cell phones, e-bikes, hoverboards and electric cars are different. While a dead battery is relatively harmless, a battery with some charge has the potential to go into a state of “thermal runaway” if damaged, a chain reaction that can eventually start a fire and release toxic chemicals.

When a battery goes into thermal runaway, O’Connor said, “it generates a lot of heat, and it keeps generating that heat” until substances in the battery start to turn into “a flammable and toxic gas.” That, in turn, makes the pressure in the battery rise.

“Boil water, it expands. The same thing happens to the (battery’s) electrolytes. So, it expands. It pressurizes the battery cell,” O’Connor said.

Once the chain reaction begins, it’s only a matter of time before the gas building up inside has to get out — either by finding a hole in the battery or making one, O’Connor said. Then, fire and chemicals rush out.

How do batteries get damaged?

Batteries can be damaged in several ways. Sometimes, it’s physical damage from dropping them or puncturing them in some way — this is common in devices like e-bikes and scooters just because of the way they’re used, O’Connor said.

Lithium-ion batteries do have some safety features that can protect them from drops or punctures. They’re encased in strong layers of metal and plastic.

But if the battery does become damaged and ignites, those protective layers can turn out to be a liability. O’Connor said “it’s tough to cool that and extinguish it and get to that battery layer with so many layers of physical protection.”

There can be other causes of damage, too, including the charging process itself. Sometimes, the charging process can overheat the battery to the point that it begins a chain reaction.

Signs of danger

Sometimes, cell phone batteries and other lithium-ion batteries show signs of damage prior to a catastrophe. You might be able to see a phone or other device expanding from the pressure being generated inside.

“If your battery starts expanding, you might see them swell up. That’s a sign if they’re creating excess heat,” O’Connor said. “Take that outside, because it might start catching on fire pretty soon.”

If a fire does break out in your home, there are ways to tell if a battery is the culprit.

A lithium-ion battery is typically a series of smaller batteries connected in a line, so it tends to make a certain sound when it is on fire.

“One of the unique characteristics would be a popping noise, which would be those battery cells popping because they’re filling up with gas,” O’Connor said. “It kind of sounds like fireworks, like those smaller crackling fireworks.”

The chemical cocktail coming off of the batteries is distinctive, too — but it’s also highly dangerous to breathe in.

“Firefighters should be donning their respirators, so they shouldn’t smell it,” O’Connor said. “They have a unique odor; you don’t want to be smelling that.”

Putting out the fire — and cleaning up

Firefighting organizations in northeast Kansas have some new technologies that are specially designed to extinguish battery fires.

In Johnson County, Fire Chief Steve Chick with Consolidated Fire District 2 said his department recently purchased specialized blankets to put out fires even on large objects like electric vehicles.

“These EV blankets will allow us to cover the vehicle or items on fire and essentially contain/smother a fire which might not be responding to traditional application of water,” Chick said.

In Douglas County, Consolidated Fire District #1 has a trailer that can spray a thin foam agent onto the fire, suffocating it more effectively than water can.

photo by: Contributed

Douglas county Consolidated Fire District #1 deploys the F500 foam trailer in July of 2022.

But once the fire is out, the cleanup can be complicated. The poisonous gases mix with the smoke and soot and can remain on a surface long after the fire is over.

“They’re very hard to get out of your walls and your ceilings and everything,” O’Connor said.

There are specialty companies that can remediate properties with lithium-ion battery damage, but it is generally an expensive process, and whether it will work depends on the severity of the fire.

Keep yourself safe

O’Connor urged people to read and follow the manufacturer’s guidance on how to charge and store devices with lithium-ion batteries. He said they should only use the charger that came with the device and avoid buying cheap after-market chargers online.

Additionally, he said, customers should be mindful of what kinds of protections are built into their batteries. A typical bike or scooter battery is much less technologically advanced than a cell phone battery, and that can lead to a dangerous situation.

Never store devices with lithium-ion batteries in places where they could hinder your escape if a fire were to break out. O’Connor said that one of the less obvious dangers of e-bikes and scooters is that people tend to store them inside, near doors and windows.

“They’re leaving it right next to their door, which is their only escape in case of a fire. So when they are catching fire, it’s blocking the exit (and) they’re pretty much doomed,” O’Connor said.

And, even though cell phone batteries are smaller and smarter than those in many other devices, you should still be careful about where you put them.

“People might sleep with a cell phone under their pillow or next to their head at night; people typically wouldn’t sleep with like a propane cylinder next to their head,” O’Connor said.