E-mobility Devices

Watch for several warning signs of an unsafe battery. These include swelling or bulging of the battery, noticeable overheating during charging, damage from crashes or collisions, strange smells, and any signs of fire or smoke.

Electric bike, hoverboard, and scooter owners should always examine batteries for physical damage like punctures or dents, leaking, swelling, and other signs of thermal runaway, including an extremely hot-to-the-touch battery, unusual smells, smoking batteries, or hissing or popping sounds. If a device is parked outdoors and unattended, it may experience damage without the owner’s knowledge.

You should not charge in locations that block fire exits, entryways, front doors, or hallways. According to research, 49% of riders charge at home block exit paths, which has been a contributing factor in several deaths. This is particularly dangerous because a battery fire can engulf a room in flames in less than 20 seconds.

E-bike or e-scooter batteries can catch fire even when they are not charging if they have sustained damage that would cause them to enter thermal runaway. A thermal runaway incident can take place hours or even days after an e-bike has sustained damage or been exposed to extreme hot or cold temperatures. If an e-bike has been in an accident or fall, owners should take extreme caution.

When charging your electric scooter, e-bike, or hoverboard device:

• Always follow manufacturer instructions when charging batteries
• Only use the charger supplied or recommended by the manufacturer — avoid counterfeit chargers
• Never charge your device near an exit, as it could block your escape in the event of a fire
• Do not overcharge batteries. In a recent survey by UL Standards & Engagement, more than half (55%) of e-bike owners admit to leaving devices plugged in after reaching full charge
• Never leave batteries unattended while charging or charge overnight while sleeping
• Do not charge batteries in extremely hot or cold temperatures
• Charge batteries before they completely lose power
• Never charge a device near heaters, direct sunlight, or other heat sources

Most batteries powering electric bikes, scooters, and hoverboards are lithium-ion batteries. You can often find the battery type listed on the battery case, in the instruction manual, or marked on your device by icons or symbols that note “Li-Ion” or “Li+.”

Only buy batteries and chargers that have been evaluated to safety standards, such as UL 2849, UL 2849 or UL 2272, and that have been approved for use with your device by the manufacturer. This means that the battery has been designed and constructed according to rigorous safety requirements. Counterfeit and unapproved replacement batteries do not offer the same protections as those that conform to safety standards and pose a higher risk of thermal runaway. Follow all instructions and markings provided by the manufacturer to reduce the risk of fire, electric shock, or injury.

There are several warning signs that indicate the need for battery replacement. These include swelling or bulging (which prompted 28% of replacements), overheating issues (24% of replacements), damage from crashes (16% of replacements), or any signs of fire (11% of replacements).

Look for devices that comply with safety standards, including UL 2849 for e-bikes, UL 2272 for personal e-mobility devices, and UL 2271 for batteries used in light electric vehicles. When an e-bike, e-scooter, or hoverboard is certified to a UL standard, the product’s batteries, chargers, electrical systems, and more, have been designed and tested to withstand conditions that the device may encounter during normal use including high temperatures, water exposure, and vibration. Certain tests even account for accidental drops, falls, or overcharging issues.