Milton explains how EV batteries increase fire risk — and what to do about it

“Anything with lithium-ion batteries that could come in contact with saltwater needs to be moved out of upwelling areas,” Kathy Perkins, Pinellas County emergency management director, said during a Wednesday morning briefing. Lithium-ion batteries are also used to power golf carts, electric bicycles, and scooters.

“We saw it: they exploded, they started fires,” Perkins said. “If it's inside your house or under a condo, we don't need to put a fire in the middle of it because nobody's going to be able to come out and help you.”

Florida State Fire Marshal Jimmy Patronis issued a similar warning Monday, confirming that 48 lithium-ion batteries caught fire in the region nearly two weeks ago after Hurricane Helen swept through the region. Patronis said in a statement that 11 of these fires were linked to EVs.

The potential risk of battery fires from EVs exposed to salt water should be taken seriously, said Albert Gore, executive director of the Zero Emission Transportation Association, or Zeta, an industry group that promotes EVs. ZETA has released an online guide to help EV owners prepare ahead of a hurricane.

“These storms bring risks that are beyond our everyday risks that we understand,” Gore said. “When you add a new technology whose knowledge doesn't carry over from generation to generation like a gas car, we need EV owners to know the right information about what the risks are, what's not, and what's not. to do.”

Although Gore said that EV batteries are rigorously tested to assess how resistant they are to water and dust ingress, the technology can create problems by being submerged in salt water.

Salt water can corrode and damage your EV's battery pack, especially if the vehicle has been underwater for long periods of time, which can range from hours to days, according to ZETA.

A compromised battery can short circuit, causing permanent system damage and in some cases fire.

Salt water can similarly eat into a gas-powered vehicle, which also has a battery. But Gore said the fire risk is different because these batteries have lower voltages than those typically found in EVs.

Moving your vehicle from an area that may be flooded with salt water is a simple first step that all EV owners should add to their hurricane preparedness plans.

While freshwater flooding can damage vehicles, it may not pose the same fire hazard, according to JETA. Freshwater does not have the corrosive effects of saltwater, which can corrode an EV battery's coating. Salt water is also a much more efficient conductor of electricity.

Wherever you go, ZETA recommends making sure it's at least 50 feet away from buildings or other flammable materials.

Avoid leaving your car plugged in during storms. In St. Petersburg, Fla., officials advised EV owners to drain their batteries below 30 percent charge.

“The risk is related to the amount of energy in the battery,” Gore said.

A fully charged battery is more prone to fire if damaged by immersion in salt water than a depleted battery.

If your vehicle is submerged, it is important to have it checked by a professional before driving after the flood waters recede. Even if the car feels good, there's still a risk of battery damage, Gore said.

ZETA also recommends treating your vehicle as if it had been in an accident and contacting your insurance provider immediately.

In Monday's statement, Patronis called the compromised EV a “ticking time bomb.”

“After a storm, if you have an EV that's flooded with salt water and it's left in your garage or near your home, please move it to a safe location immediately so you can focus on fixing your home instead of rebuilding it. Because of the fire,” he said.