How to reduce the low risk of battery fires from your EV and on planes

This article is a preview of The Tech Friend newsletter. Sign up here to get it in your inbox every Tuesday and Friday.

After I wrote recently about how you can reduce the risk of fires from rechargeable batteries, many readers had questions including:

  • What’s the danger of fires from batteries in electric cars?
  • What happens if a laptop battery catches fire on an airplane?
  • Should you be worried about buying replacement batteries for your phone or other gadgets?

I’ll tackle those questions below. I also want to keep the risks in perspective.

The lithium-ion batteries in our smartphones, laptops, electric tools and electric cars are generally very safe. We want to take sensible precautions but also not overly fixate on unlikely dangers.

It still makes sense to know about the potential fire danger risks from rechargeable batteries and how you can further minimize them.

How safe are the batteries in electric vehicles?

My focus in previous reporting was on the safety of the rechargeable batteries in transportation devices such as e-bikes and electric scooters. Some of those devices appear to be the cause of an increase in battery-related fires in cities such as New York, London and San Francisco.

Understandably, many of you also asked about electric cars, which use the same type of lithium-ion batteries as your smartphone or e-bike — but on a much larger scale.

In general, the larger the battery, the more energy it holds and therefore the bigger fire it could cause.

Chris Cramer, senior vice president and chief research officer for the safety organization UL Research Institutes, said the available research is finding that electric cars are generally less prone to fires than vehicles with gasoline-powered engines.

But “when they do have a fire, it’s a really bad fire,” Cramer said.

To reduce the low fire risk of your EV, Cramer suggested that you follow the charging instructions in your owner’s manual. And if you’re in a crash, take your car to an authorized dealer or another repair specialist to check for potential battery damage.

Manufacturers that build electric cars make sure the batteries are generally well protected, but damage tends to increase the risk of a battery fire.

If you’re still concerned about the fire risk, Cramer said you might consider charging your EV somewhere other than your garage overnight, when it might take you longer to escape your home if there’s a fire.

Alternatives include charging your car during the day, at work or on a side area separate from your home.

Buying a smaller car is the solution to your biggest worry about EVs

Which electric vehicle is right for you? Here’s a guide to help you decide.

Are lithium-ion batteries more of a fire risk when the device is being charged?

But Cramer said that damage to a battery can increase its potential risk of fire even when it’s not plugged in.

Please know that you cannot put out a lithium-ion battery fire with your home’s standard chemical fire extinguisher.

Water extinguishers and residential fire sprinklers have been effective at initially suppressing fires from smaller batteries like those in laptops and smartphones, said Daniel Flynn, chief fire marshal with the New York Fire Department.

If you see smoke or the beginning of a fire from larger batteries, Flynn said you should get away immediately and call 911. Lithium-ion battery fires can spread very quickly, emit toxic fumes or explode.

If you have a device with a battery that is swollen or smells funny, stop using it and don’t charge it.

Leo Raudys, CEO of the battery recycling organization Call2Recycle, suggested putting the battery or device in material like cat litter or sand, and away from flammable materials.

Damaged lithium-ion batteries need to be handled by specially trained recycling centers. Try a web search for the name of your city or county and “municipal household hazardous waste recycling center.”

I have more advice about how to safely recycle smartphones or other products with undamaged rechargeable batteries.

How to find reliable and safe replacement batteries

Kyle Wiens, CEO of the consumer advocacy group and repair community iFixit, said that if you’re looking for replacement lithium-ion batteries for your devices, buy from a trusted store that offers you a solid warranty.

He advised against buying rechargeable batteries from eBay or Amazon because of the small risk you could unwittingly buy an unsafe battery from a disreputable vendor. (iFixit sells batteries on its own website and on Amazon.)

Amazon and eBay didn’t respond to requests to comment.

(Amazon founder Jeff Bezos owns The Washington Post. Interim CEO Patty Stonesifer sits on Amazon’s board.)

Wiens said most do-it-yourself battery replacements are safe, but you should still take precautions.

If you’re replacing a smartphone or laptop battery, do the repair task on a concrete area, in a well-ventilated area and far from materials like curtains that could catch fire.

Run your battery down below 25 percent charge or less before you replace it, iFixit advises. With little juice, the battery is much safer.

Or you might want to turn to a trusted repair professional. Here’s advice on finding trustworthy repair help for your gadgets.

What about the risk of in-flight fires from rechargeable devices?

It does happen, but rarely.

That’s why airlines tell you not to put lithium-ion batteries in your checked luggage.

Cramer said that airline crews have training and equipment to throw overheating laptops or other devices with rechargeable batteries into fire containment bags.

Raudys told me that when he travels with his laptop, he keeps it in a fire safety sleeve. That’s not practical or necessary for most people. (The sleeves can cost hundreds of dollars.)

Cramer said the combination of airplane crew training and our vigilance keeps flights safe from battery fires.

“The current level of risk is understood and the mitigation that is in place has been successful,” he said.

If you’ve rented a car recently, the rental company might have pushed you to go with an electric model.

Renting an EV can be a bargain and it’s a low-stakes way to try an electric car.

But my colleague Chris Velazco also ran into snags with his rented EV, including a two-hour, multistop hunt to find a working electric charger.

The good news, Chris said, is that Google Maps has useful options to search for charging locations on your driving route. Chris said he centered Google Maps near places he planned to drive through and searched for “charging stations.”

As you can see in these images, you will get a list of locations with charging options. You can specify which plug type your car uses.

(Apart from Tesla and a couple of other EV models, most electric vehicles in the United States have used the charging type known as “CCS.” Tesla’s type of plug is known as “NACS.”)

Read more from Chris on the joys and the pitfalls of renting an electric vehicle.