June 28, 2016
Hoverboards have received more than their share of attention from consumers, first because of the excitement of owning the hottest product in the market and then because of the hazardous conditions caused by untested Lithium-ion (Li-ion) battery packs.
In answer to consumer concern and the U.S. Consumer Product Safety Commission, which investigated more than 60 hoverboard fires in 20 states, UL introduced new safety testing and certification criteria, UL 2272 Safety of Electrical Systems for Self-Balancing Scooters to help evaluate these devices for electrical and fire safety. (It is important to note that while the UL standard works to help ensure the electrical system of the product is safe, it doesn’t address actual riding safety.)
UL 2272 evaluation of hoverboards has been very thorough, 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. Below is just a sampling of the tests that are conducted on the hoverboard during the certification process.
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 as a whole. Electrical tests such as the overcharge and overdischarge tests assess the electrical system safety.
Li-ion batteries are an important technology because they have a lot of power and are used regularly with a very small failure rate, approximately 1 in 10 million. Boyce says that the Li-ion battery is relatively safe but, with the billions of batteries used around the world on a daily basis, it is inevitable that some failures will occur. UL’s work is aimed at helping to reduce the number of those failures.
Mechanical testing is conducted by looking at stressors from everyday use such as vibration or banging something against the product, which may cause parts to loosen and increase the chance for injury. The drop test demonstrates a number of ways in which extreme force can affect the product’s overall safety. If the outside of the hoverboard becomes cracked because it’s been dropped, damage to the internal components and the internal battery may occur or loose wires 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.
Reintroduction to Market
The UL 2272 Standard was released in late January 2016 and manufacturers began submitting products for review in February. Just a few months later, UL certified a number of hoverboards with more underway. Access UL Certified hoverboards by entering “FKIS” in the category field.
“UL certification through our independent safety evaluation and ongoing production assessments reinforce safety for global consumers,” says Boyce.
As the products are reintroduced into the market, consumers should look for the UL holographic certification mark on the hoverboard and the UL promotional mark that manufacturers place on hoverboard packaging. Claims that pieces or parts of a hoverboard are UL certified do not address the overall safety issues originally experienced by users.
For more information about UL’s work with hoverboards, please visit http://ul.com/hoverboards.