November 21, 2017
For a device that rolled from the exhibition halls of CES 2015 and into the homes of hundreds of thousands of consumers, the hoverboard’s moment in the sun quickly faded as reports of hoverboard "explosions" surfaced in late 2015.
Five days before Thanksgiving, a hoverboard battery was charging in the home of a Lafitte, La. resident when the homeowner “saw flames shooting from both ends.”
In another incident, a charging hoverboard exploded in a Hong Kong flat, destroying it, while in London, 20 firefighters responded to a hoverboard fire on November 9, 2015. Like the other incidents, the device had been charging when the owner heard a “loud bang.”
Many consumers were aware of the dangers of falling off the device, but no one knew at the time of the device’s potential to self-ignite and the resulting damage from this type of failure.
To help address consumer concerns, UL worked within the industry and with organizations such as the U.S Consumer Product Safety Commission (CPSC) to introduce a new safety standard in late January of 2016, UL 2272, Standard for Electrical Systems for Self-Balancing Scooters (later in the year it was expanded to cover all Personal e-Mobility Devices).
At the end of February 2016, the CPSC urged importers, manufacturers and retailers of hoverboards to ensure their products complied with “applicable voluntary safety standards, including all referenced standards and requirements contained in UL 2272.”
Note: While the UL Standard works to help ensure the electrical system of the product is safe, it doesn’t address actual riding safety.
Despite the CPSC’s public letter, hoverboards that did not meet the standard continued to be imported and sold to consumers in the U.S., resulting in additional injuries, property damage and fatalities from device fires between 2016 to 2017. These reports prompted the CPSC to recall an extra 3,900 hoverboards on November 14, 2017, due to the risk of a battery fire, bringing the total number of recalled products to 520,100 since the initial recall of devices in July 2016.
Before purchasing a hoverboard or any personal e-mobility device such as e-skateboard or e-skates, consumers should look for the UL 2272 holographic certification mark on the device itself, as well as for the UL 2272 promotional mark that manufacturers can place on the product packaging. This means the electrical system has been tested to UL 2272 and meets the criteria outlined in the safety standard.
It is important to note that claims that elements or parts of a personal e-mobility device are UL certified do not address the overall electrical system safety issues initially experienced by users.
Additionally, while the CPSC has recalled specific hoverboards, these recalled products might still be found in the secondary marketplace, including on auction platforms, at garage sales and flea markets, to name a few.
UL Certified Hoverboards
Consumers can find certified hoverboards and other personal e-mobility devices through the UL Online Certification Database. To view the directory, select the button “Visit the UL Online Certification Directory” or “Visit the ULC (Canada) Directory.”One can search three ways: by company name; UL category code; or UL file number.
- To search by company name, just enter the company or manufacturer name into the appropriate search field.
- To browse the list of UL certified hoverboard manufacturers, enter “FKIS” in the category field, then select the “search” button.
- To verify the validity of a UL Certification Mark, enter the file number found on the hoverboard’s holographic mark in the “UL File Number” field.
Finally, learn more about how UL tests hoverboards in this excerpt from the original Inside UL article, Behind the Scenes: How UL Tests Hoverboards to UL 2272 Requirements.
UL 2272 evaluation of hoverboards has been extensive, beginning with tests related to everything from the construction, performance, electrical and mechanical to the verification of markings in the instruction manual.
Ken Boyce, UL director of principal engineers, says these new safety requirements began with a concept to evaluate the charger and battery pack as well as its associated electronics for an overall safety review.
Lithium-Ion (Li-ion) batteries are an important technology because they have a lot of power and are regularly used worldwide. Boyce says that the Li-ion battery is a relatively safe technology, but with the billions of batteries used daily around the world, it is inevitable that some failures will occur. UL’s work is to help reduce the number of hoverboard failures.
Fires and explosions from the hoverboard primarily occurred from the batteries, so UL adopted a coordinated safety strategy and reviewed materials and components by looking at the product’s electrical system.
Below is a sample of the tests conducted on the hoverboard during the certification process:
Electrical testing such as the overcharge and over discharge tests assess the electrical system safety.
Mechanical testing looks at stressors from everyday use such as vibration or banging something against the product, which may cause parts to loosen and increase the chance of injury. If the enclosure of the hoverboard becomes cracked because of mechanical stresses, this could cause damage to the internal components and the internal battery, or loose wires may become accessible, potentially causing an injury.
Environmental testing evaluates water exposure and thermal cycling, which includes splashing water and partially immersing the hoverboard. It’s important to make sure the product’s design can effectively keep water away from the electrical circuitry. Water contacting the internal circuits can cause shock and fire hazards.
Material and component tests include checking for flame resistance of non-metallic materials and motor tests that verify there if there is a potential for the motor to overheat. The locked rotor test evaluates the motor’s ability to safely withstand a situation in which the rotor is prevented from moving, showing the hoverboard may still function in adverse conditions.
Finally, UL evaluates the instruction manual and labeling (marking and instruction) of the product. Boyce says that consumers should read the manual and adhere to the instructional markings on the product, which include how to charge the battery pack. All hoverboards should be marked with the manufacturer’s name, model or part number, electrical ratings and the date of manufacture. It must also be marked with charging instructions.
For more information about UL’s work with hoverboards, please visit http://ul.com/hoverboards.