By John Kriz
Rechargeable lithium-ion batteries are everywhere.
With more and more things we use every day – motorcars, e-bikes and scooters, leaf blowers, chain saws, drills, vacuums, watches, mobile phones, laptops, drones, iPads, cameras, solar panel power storage, children’s toys – being powered by these batteries, the issue of safe use comes to the fore. And lithium-ion batteries can be, or become, unsafe and fire hazards.
To get a better idea of the safety issues of these ubiquitous batteries, and how residents can manage their growing battery portfolios in the safest manner, the New Canaan Sentinel sat down with our town’s leading local fire safety experts: Fire Chief Albert Bassett, Deputy Fire Chief William Perritt and Fire Marshal Paul Payne. In addition, they recommended the National Fire Protection Association (NFPA) and UL Solutions (formerly Underwriters Laboratories) as useful information sources. This is what we learned.
Battery Fires
Lithium-ion batteries can and do catch fire, and such fires are especially dangerous because of the intense heat generated when they burn, and difficulty in extinguishing the fire. It’s not an urban legend.
There have been serious, recent house fires in New Canaan. The causes of these incidents remain undetermined at this time, but lithium-ion batteries cannot be ruled out.
UL states that, “The proliferation of lithium-ion batteries and the products that run on them has resulted in an exponential increase in incidents resulting in injuries and fatalities.”
According to data compiled by UL for 2024 (most recent full year data) in the USA there were 550 incidents involving problematic lithium-ion batteries, resulting in 126 injuries and 14 fatalities.
How Do Battery Fires Happen?
A fire could start elsewhere, and then spread and engulf an otherwise safe battery, causing it to burn. This is a concern for firefighters, who are fighting what seems to be a simple fire, with that fire taking a serious turn for the worse when a nearby battery is suddenly engulfed, ‘turbocharging’ the risk. And the bigger the battery (such as for an e-bike) the bigger the potential risk.
As well, the battery itself can be the cause of a fire. Often this is due to improper charging practices, placement of the battery near flammable material, or the battery itself being of dubious quality. Note that airlines prohibit battery-powered devices from checked luggage.
Take smart phones as an example. According to UL, there are more than seven billion smart phones on the planet, all powered by lithium-ion batteries., More than half of all iPhones in use are second hand, and will eventually need battery replacement due to ‘capacity fade.’
However, instead of purchasing original equipment manufacturer (OEM) approved and third-party-tested batteries, people might choose to purchase aftermarket batteries. Says UL, “Replacement batteries approved by the smartphone manufacturer should function similarly to the originals, with the same safety certifications, performance and cycle life characteristics.”
Aftermarket batteries are another story. Continues UL, “These aftermarket batteries often come at a lower price than OEM-approved ones, with promises of comparable or better performance. OEM-approved batteries normally undergo various international or regional safety standard evaluations and tests to obtain safety certifications. This helps ensure product performance and reliability and provides a level of fire risk mitigation. In contrast, most aftermarket replacement batteries not recommended for use by the manufacturer typically lack such claims in their product labels, suggesting a lack of certification to any battery safety standard.”
As mobile phones are often kept in a pocket or purse, the risks of battery failure are exacerbated.
The punchline: Buying a cheap aftermarket battery might not really be cheap if you factor your and your family’s health and home into the equation, be it for a phone battery or anything else.
Safety Tips
Based on input from New Canaan’s leading fire safety experts, plus data from the National Fire Protection Association (NFPA) and UL Solutions:
• Batteries not designed for a specific use can be dangerous. For example, a battery might fit in a device, but be the wrong voltage for the device, potentially creating a hazard due to the mismatch.
• Batteries, like any other object, can be defective, and overheat, catch fire or explode.
• Only use batteries listed by a nationally recognized testing organization, such as UL. Some batteries might be ‘aftermarket knock-offs’ and not made well. If a battery’s price is too good to be true, that should be a warning. It’s best to seek replacement batteries from the device’s manufacturer to help ensure that the correct, certified battery is being installed.
• Be aware of counterfeits. This can happen even with OEMs, and they can be difficult to spot. Look for misspellinsg (like this!) on the label, or poor label placement or printing.
• Only use the charging cord that came with the device. Using the wrong charger is a key cause of ‘thermal runaway,’ which results in excessive battery heat and fire.
• Don’t charge a device under or near a pillow, bed, couch or anything flammable. The same goes for storing batteries. Keeping batteries (especially large ones for devices such as e-bikes) in a shed away from the house is a good safety idea.
• Safe battery charging requires the correct voltage. When traveling to, say, Europe, which uses 220–240V at 50Hz, while the U.S. uses 110–120V at 60Hz, you’ll need not only an adapter for the plug, but also a voltage regulator. Charging a battery at the wrong voltage level can cause overheating and fire.
• Don’t keep charging the battery once it has reached its full charge. (An example is charging your phone overnight next to your bed.) This is another route to thermal runaway and fire. Many devices have holders where you store as well as charge the device. Convenient though they may be, leaving the device charging long after it has a full charge can cause battery failure. Set your mobile phone on a timer and unplug the device when it has been charged. Fire Marshal Payne sees this overcharging risk all the time during home fire safety assessments. (If you’d like a free home fire safety assessment, call the fire marshal at 203-594-3030 to schedule an appointment.)
• Keep batteries at room temperature — at least between freezing and 105F. (Think of a battery stored in a garage or shed that gets very cold or hot.)
• If the battery fails to fully charge, takes too long to charge, fails to hold a charge, emits an odor, gets overheated, changes color or shape, makes a noise, or leaks move it away from anything flammable and properly dispose of it. If in doubt, call 911.
• Dropping a battery can cause irreversible damage and fire risk – even if there is no visible damage. Replacing the battery is best seen as ‘Better safe than sorry.’
• Keep batteries away from contact with metals (such as storing them in a drawer or box), as contact can cause the battery to short out.
• Be sure you have working smoke detectors. Having a heat detector in the garage is a good idea, too.
Disposal
The best place to dispose of a lithium-ion battery is the transfer station, where there are marked bins. If your battery is damaged, leaking or otherwise thought to be dangerous, call 911 and be sure the operator knows that a possibly dangerous battery is the issue.
