Electrical Safety Tips for Users of E-Bikes and E-Scooters

A version of this article will appear in the In Compliance section of the Winter 2022 issue of NFPA Journal. 

Recent discussions around electric micromobility devices, such as e-bikes and e-scooters, have left a lot of people rather charged up. Proposed changes by the New York City Housing Authority (NYCHA), for example, would prohibit residents and guests from keeping e-bikes or e-scooters within NYCHA apartments or building common areas. Delivery workers have raised concerns that such a ban would adversely affect their livelihoods, since charging the e-bikes that they use to make deliveries would no longer be possible in their homes. 

Watch a related video on e-bike and e-scooter fire safety

Big cities aren’t the only places where authorities have moved to ban e-bikes or e-scooters from buildings. Mackinac Island, a small vacation island in northern Michigan, has become well-known for regulating the means of transportation that are permitted on the island. Since 1901, automotive transportation has been banned, leaving most travel to be done on foot, by bicycle, or by horse and carriage. Not long ago, island authorities banned e-bikes within certain buildings and have further prohibited the use of e-bikes that have functional throttles when traveling around the island. (For an overview of the safety hazards associated with electric micromobility devices and the regulations proposed to address those hazards, see “Full Throttle,” a feature story that appeared in the Fall 2022 issue of NFPA Journal.)

SAFETY RESOURCES: Visit nfpa.org/ebikes to explore other NFPA resources related to e-bike and e-scooter fire safety

Improving e-bike and e-scooter safety is providing much of the momentum behind these changes. In 2022 alone, the Fire Department of the City of New York (FDNY) has reported investigating 130 fires related to lithium-ion batteries regularly used to power e-bikes—fires that have resulted in five deaths and dozens of injuries. In October, the Consumer Product Safety Commission (CPSC) recalled about 22,000 e-bikes whose “lithium-ion batteries can ignite, explode, or spark, posing fire, explosion, and burn hazards to consumers,” CPSC wrote in a statement.

Investigators say a fire that killed an 8-year-old girl in Queens last month was likely ignited by an e-bike battery charging inside an apartment unit overnight. A fire in December 2021 killed a New York City man who was running a business charging e-bikes within his residence. Two teenagers narrowly escaped the same fire themselves by shimmying down a pipe mounted to the building’s exterior wall. Over the summer on Mackinac Island, an e-bike battery that exploded and melted left both the homeowner and firefighters with injuries related to smoke inhalation. In all of these cases, the personal decisions made by individuals to charge e-bikes in their homes left others in harm’s way.

While there are no specific codes in place for the charging of e-bikes or e-scooters themselves, there are portions of codes, including NFPA 70®, National Electrical Code® (NEC®), that can help people be safer while doing so. There are also additional areas that can be addressed to further ensure safer charging. 

Avoid overloading circuits and overcharging batteries

Electricity is necessary to charge e-bike batteries, meaning the battery being charged and the device charging the battery can be potential fire hazards. An aspect that can sometimes be overlooked, though, is that the structural wiring within the building can be a risk as well.

Ensuring that the electrical infrastructure in the building is properly installed and capable of delivering electricity for safe charging is where the NEC comes into play. If we consider the deadly NYC fire that killed the man who was charging e-bikes out of his residence, we can assume that overloading the circuit may have been part of the issue. When multiple e-bikes are being charged at once, the load on the circuit supplying power for charging increases.

Another scenario that could have compounded the imposed load on the circuit is that it was a continuous load. The NEC defines a continuous load as one where the maximum current is expected to continue for three hours or more and requires any continuous loads to be factored in at 125 percent. As an example, a 20-amp circuit is only permitted to be loaded to 16 amps when continuous loads are involved (16-amp continuous load x 125 percent = 20 amps). With e-bikes being charged for over three hours and multiple e-bikes being charged simultaneously, the circuit could have easily been highly overloaded, which could have begun degradation of the wiring, causing it to eventually break down and become a possible ignition source.

Furthermore, overcharging batteries is something that an individual can easily do without intending to, but it can have a catastrophic effect resulting in fires and death. Recently, Inside Edition released a video that shows the impact that overcharging batteries can have and how quickly micromobility devices can burst into flames because of it. It is crucial that individuals that are charging the batteries of micromobility devices follow the manufacturer’s instructions for proper charging and do not overcharge the batteries. Overcharging not only puts their own lives at risk but also the lives of many others.

Look for listed devices, batteries, and charging equipment

Another area that must be considered around e-bike charging safety is the product itself. Consumers should be sure that they are purchasing a high-quality product that has been listed by a nationally recognized testing lab and labeled accordingly. Part of the charger system evaluation is the plug-in charger itself. It is important for consumers to understand that the charger that comes with the e-bike is what gets tested as part of the listing and therefore is the only charger that should be utilized. Buying an aftermarket charger from another manufacturer could likely invalidate the listing of the e-bike and may contribute to the additional risk of a fire due to compatibility not being tested between the e-bike and the charger. There are many products out there that may be noted as compatible with an e-bike, but they may not be listed to work with a specific e-bike. 

The importance of using e-bikes and products that are listed was echoed in July when Heather Mason, president of the National Bicycle Dealers Association, encouraged their vendors and suppliers to certify their e-bikes to UL 2849, Standard for Electrical Systems for eBikes. “The bicycle industry needs to take immediate action,” Mason stated at the time. “After extensive consultations with experts in the field, e-bike and e-scooter lithium-ion battery safety is a large and immediate subject that we need to act on now. The advisement statement we have prepared for retailers takes the interest of e-bike continued growth within the industry and safety for all. If we do not address the core issue, we may see this propel to something beyond our control.”   

With the recently proposed bans on e-bikes getting many people charged up, it is important to consider that the authorities proposing these changes are doing so with public safety in mind. When improper and unsafe charging of e-bikes takes place, tragedy can follow. People who use e-bikes should continue to learn about the intricacies involved in safe charging. Doing so will not only impact their own personal safety, but the safety of their neighbors as well.

Download the E-Bike and E-Scooter Safety Tip Sheet
Corey Hannahs
Senior Electrical Content Specialist

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