Today we see more and more products with lithium-ion batteries, but we also see stories of these products starting fires and injuring consumers. Are lithium batteries safe? UL is here to answers your questions on lithium-ion battery safety.

Why are we hearing about products with lithium-ion batteries catching on fire?

Lithium-ion batteries certainly have made life easier for anyone who uses a cell phone, tablet or laptop. Compared to the classic alkaline battery, lithium-ion battery cells are little powerhouses that can store the same amount of energy in a fraction of the size and weight. Although there are millions of lithium-ion batteries in use every day, in very few but scary cases, the batteries have failed, releasing all that stored energy in a rush and causing a fire or explosion.

There are five factors that contribute to malfunctions in lithium-ion batteries.

1. Lack or shortcoming of safety features in the product.

2. Lack of stringent battery manufacturing quality control. The battery manufacturing process is critical as even the tiniest impurity can get into the battery cell and cause a short circuit. Short circuits cause heat that makes the battery expand and build pressure, causing it to burn or explode.

3. Mismatch of battery and charger performance capabilities.

4. Device performance and environmental issues such as extreme heat, vibration, flexing and impact.

5. The history of how the product was used.

Is there anything I can do to help keep my products with lithium-ion batteries safe?

Yes. There are a number of ways to help keep your products, particularly the lithium-ion battery, in good shape.

  • Use only the battery and charger provided by the manufacturer. Do not buy a charger for your product from a different manufacturer. Manufacturers provide a battery and charger that are perfectly matched.
  • When buying these products, look for the UL Mark. This means representative samples of the product’s battery and charger have been evaluated for safety.

  • Only charge your product for as long as the manufacturer recommends. Do not overcharge your product.
  • When charging, keep your product away from any combustible materials (under a pillow, bedding or other materials) and anything that might prevent adequate air flow.
  • Keep your product away from extreme heat. For example, don’t have your cell phone in direct sunlight.
  • If you drop your product, such as a cell phone or laptop, and you see visible damage, take it to a professional to look at. Severe impact can damage any type of battery.
  • Avoid crushing or bending a device and/or charger during use. Some newer devices are especially thin and can bend in your pocket, at the bottom of your gym bag or even when slipping underneath the car seat.

How do I properly charge the lithium battery in my product?

For optimum performance, it’s best to re-charge a battery only when it has a low state of charge and then fully charge it to 100 percent.

If you see changes in your product’s performance and it takes longer to charge, or doesn’t keep a charge, your battery may be near end of life, and you may need a new product.

And please, never place regular batteries in a rechargeable battery charger. Non-rechargeable batteries are not designed for recharging and can become hazardous if placed in a battery charger.

How is UL involved in the safety of lithium batteries?

UL has been researching and testing lithium-ion batteries for over a decade. As lithium-ion batteries show up in more and more household and industrial products, UL is working to update existing safety standards and create new ones. We conduct numerous tests of both small and large scale batteries – from wearable fitness devices to electric vehicle batteries. As a recent example, UL developed new safety requirements that addressed the fire, shock and hazards associated with hoverboards. The safety requirements began with a concept to evaluate the charger and battery pack and included all of the associated electronics for an overall product safety review. Consumers can now look for the UL Mark when purchasing a hoverboard.