With the rising popularity of electric vehicles, it’s important to address the safety concerns associated with the battery they use. In fact, for National Electrical Safety Month last month, the NFPA and Electric Safety Foundation International announced they would be emphasizing EV-related safety as part of the event.

So for electrical contractors, it is crucial to share safety measures with customers who own or plan to purchase EVs.

Lithium-ion batteries consist of lithium-ion cells that store and release electrical energy, providing power for operation. These batteries have many applications, including laptops, cellphones, cameras, e-bikes and, of course, EVs. However, they can cause dangerous fires and explosions. Lithium-ion battery fires haven’t been a huge problem in the past, but they are occurring more frequently now. The New York City Fire Department (FDNY) reported about 220 lithium-ion battery related fires in 2022, which is significantly higher than the 40 such fires reported in 2020. In 2019, the first year FDNY started tracking e-bike fires, only 13 were reported.

FDNY Commissioner Laura Kavanagh told reporters in March 2023 that “In all of these…lithium-ion fires, it is not a slow burn; there’s not a small amount of fire, it literally explodes. It’s a tremendous volume of fire as soon as it happens, and it’s very difficult to extinguish, and so it’s particularly dangerous.”

One of the primary reasons EV batteries catch fire is thermal runaway, which occurs when the heating of a device is accelerated by temperatures increasing, which causes more energy to be released, and further increases the temperature of a device. In the case of EVs, lithium-ion batteries can heat up uncontrollably, and then batteries can catch fire or explode. It’s worth noting, however, that lithium-ion batteries are built to be safe. Of the 170,000 vehicle fires every year, only about 25 EV fires occur per 100,000 vehicles. In comparison, internal combustion vehicle fires occur (on average) about 60 times more often, at 1,530 incidents per 100,000 vehicles.

EV fires can be triggered if a battery has been damaged, if it’s overcharged, if there is external heat exposure or if there are manufacturing defects in the battery or charger. Here are some safety tips that electrical contractors can share with customers to help them stay safe:

2. Use proper charging equipment, ideally from the manufacturer.

• Avoid using unauthorised or third-party charging equipment.
• Make sure products comply with UL standards for EVs, for example, UL 2202, Electric Vehicle Charging System Equipment (AC to DC).

2. Avoid overcharging or leaving an EV plugged in overnight, especially if the charger is a Level 2 or Level 3 DC fast charger.

• Overcharging the battery can cause excessive heat buildup, increasing the risk of fire. Once the battery is fully charged, unplug the EV from the charging station.

3. Don’t overload the electrical outlet or power supply by powering too many devices at once.

• Connecting multiple devices to the vehicle’s electrical system for charging simultaneously can overload the system, increasing the chances of overheating and potential fire hazards.
• An overload could cause circuit wiring to overheat, which could lead to a fire.

4. If your EV needs repairs or maintenance, seek qualified professionals or the manufacturer’s authorised service center.

• Attempting DIY repairs without adequate knowledge and experience can lead to mishandling of the battery, increasing the risk of fire or other accidents.

5. If you notice any damage to the EV or signs that the battery could be damaged, stop using the vehicle or take it in for repairs quickly.

• Examples of how the battery or any related components could show signs of damage include unusual odours, leakage, swelling or a change in colour.