Over recent years, the use of lithium ion batteries has become widespread in consumer products such as laptops, smartphone, hoverboards, electric scooters and bicycles, and power banks. Unfortunately, many companies have been forced to recall their products over thermal events involving those products’ lithium ion batteries.
Manufacturers can mitigate their risks of fire hazards with lithium batteries by carefully choosing the right supplier, ensuring that batteries meet expected global industry standards and care is taken to ensure that the batteries are properly integrated into the products with appropriate battery management systems to mitigate the risk of thermal runaway. The latest revision of UL 2272 (Standard for Electrical Systems for Personal E-Mobility Devices) provides a good example of attention not just to the manufacturing and design of the battery but all aspects of the product and the manner in which the battery and motor operate together in the product. Emphasizing the effectiveness of UL 2272, the CPSC stated in its April 2020 report that despite numerous fires in products that were not compliant with UL 2272, including two fatalities, it was not aware of known substantial fires associated with products certified to the voluntary standard.
Despite best efforts, thermal issues do arise with lithium batteries. Proper storage and handling practices can also mitigate the likelihood of thermal events. There is no mandated regulation for lithium ion battery storage; just guidance and recommended best practices from various agencies. The following guidelines for battery storage were derived based on numerous sources, including but not limited to, guidance from the Occupational Safety and Health Administration and the National Fire Protection Association:
- When storing, remove the battery from the equipment.
- Batteries should be segregated from other materials in a warehouse and stored in a non-combustible, well-ventilated structure with sufficient clearance between the walls and the battery stacks. There should be clearance between the batteries to allow air to circulate.
- Avoid extreme heat and freezing temperatures; avoid storage under direct sunlight or in front of a heating system, stove or other heat source.
- Keep lithium-ion batteries cool and dry during storage. Be sure not to expose the battery to condensation, excessive humidity or water.
- Lithium-ion must be stored in a charged state, ideally at 40 percent and between 30% and 50%.
- Batteries should be stacked in a manner as to prevent short circuits; avoid storing the batteries in the places exposed to static electricity.
- Batteries should not be opened, destroyed nor incinerated since they may leak or rupture and release in the environment the ingredients they contain.
Executing an effective product recall requires meticulous planning and navigating a plethora of thorny issues, including, but not limited to, reverse logistics. This is especially so when either the recalled or replacement product involves a product with a lithium ion battery.
The transportation of recalled defective lithium batteries presents a challenge, not only under CPSC’s regulations, but also under the U.S. Department of Transportation (DOT) regulations. In fact, the CPSC typically informs companies recalling products with these batteries that “a recall cannot be considered acceptable to CPSC staff if it does not comply with DOT regulations regarding transportation of hazardous materials.” Therefore, some alignment of CPSC expectations and DOT requirements, specifically the Pipeline and Hazardous Materials Safety Administration (PHSMA), is typically necessary to ensure that all rules are followed and necessary permits are procured.
The following is high-level overview of the issues that companies recalling products with lithium ion batteries will face.
Lithium ion batteries and lithium metal batteries are regulated as hazardous materials under U.S. and international transportation regulations and standards, whether shipped alone, packed with equipment, or contained in equipment. Defective lithium batteries are more likely to ignite during transportation, and may go into thermal runaway, generating intense heat. Accordingly, DOT prohibits air shipment of lithium batteries identified as defective for safety reasons, as do international air transportation standards.
While DOT does authorize ground shipments of defective batteries, additional packaging requirements apply. In addition, such batteries do not qualify for the partial regulatory relief available for shipments of small and medium lithium batteries, and must be shipped as fully regulated hazardous materials. This means, among other things, that persons preparing shipments of defective small or medium lithium batteries for transportation or transporting such shipments must have received hazardous material transportation training. Also, many carriers charge a hazardous materials surcharge for fully regulated shipments. Other carriers, such as FedEx Ground, state that they will not accept defective batteries that pose a safety risk.
In order to eliminate some of these difficulties, several companies have developed special packaging specifically for the transportation of defective lithium batteries and have obtained special permits from DOT for this packaging. The special permits provide relief from some regulations for any shipment in these packagings. Companies will find however that these packagings are expensive and can contain no more than a small number of lithium batteries. A company may also develop its own packaging and obtain a special permit from DOT for its use.
The transportation of lithium batteries continues to garner significant attention and regulations are unlikely to become more lenient. Companies facing a recall of defective lithium batteries need to consider transportation issues at the outset when developing a recall strategy. Attention also needs to be given to the plan for destruction of recalled batteries, which must be shared and approved by the CPSC when the recall falls within their jurisdiction, and may even be witnessed by agency personnel. Best practices for lithium battery destruction include:
- Dispose in accordance with the applicable regulations in country and state.
- Disposal should be performed by permitted, professional disposal firms knowledgeable in federal, state or local requirements of hazardous waste treatment and hazardous waste transportation.
- Incineration should never be performed by battery users, but eventually by trained professional in authorized facility with proper gas and fume treatment.
- Battery recycling should be done in authorized facility.
Advance planning and communication with the right regulatory bodies should smooth some of the potential pitfalls when conducting such a recall.
 Small lithium metal batteries have a lithium content of ≤ 1 gram (g) of lithium content per cell and ≤ 2 g per battery, and small lithium ion batteries have a Watt-hour (Wh) rating of ≤ 20 Wh per cell and ≤ 100 Wh per battery. For medium batteries, these limits increase to 5 g lithium content per cell and 25 g per battery and 60 Wh per cell and 300 Wh per battery respectively.