Saltwater and EV batteries
When it comes to EVs, the heart of the vehicle’s power lies in its battery, usually a lithium-ion (Li-ion) pack. These batteries are highly efficient, but they’re also sensitive to water, especially the salty kind. In September and October 2024, the Southeast U.S. was hit by hurricanes Helene and Milton, which caused catastrophic flooding. Thousands of homes were damaged, and in a particularly frightening twist, 11 electric cars and 48 lithium-ion batteries caught fire after being exposed to salty floodwaters.Saltwater is a conductor of electricity, which means it can get into the EV battery packs, triggering a dangerous reaction. When water seeps into the battery, it can cause a short-circuit between the battery's terminals, which may lead to overheating, violent fires, and even explosions. In many cases, the fire doesn’t start right away — it can take hours or even days after the exposure before a thermal runaway event occurs, causing a dangerous blaze. Once the fire starts, it’s nearly impossible to put out with regular fire-fighting methods. Firefighters often have no choice but to let the battery burn itself out.
In 2022, during Hurricane Ian in Florida, 36 EVs that had been flooded reportedly caught fire, even some that were being towed on flatbed trucks. The problem lies in how lithium-ion batteries react to saltwater. The metal terminals in these batteries, when exposed to salty water, can corrode and build short-circuiting paths that lead to fires days later. The fire hazard remains even in fully discharged batteries, meaning even seemingly "safe" vehicles after flooding could still pose a serious threat.
The risk to coastal cities
This issue is especially concerning for coastal cities where rising sea levels and hurricanes are becoming more frequent. According to a 2023 report by the International Energy Agency (IEA),In fact, areas prone to heavy rains and floods, like India’s coastal cities, are facing unique challenges. The combination of frequent monsoon floods and rising sea levels presents a scenario where more and more EVs could end up submerged in salty floodwaters, increasing the risk of battery fires in the region.
What does this mean for you?
While electric cars are generally safe under normal conditions, the growing risk of battery fires due to flooding is an important factor to consider if you live in flood-prone areas, especially near the sea. The key takeaway here is that EV owners should take extra precautions when natural disasters loom, particularly hurricanes and floods. Here's what you can do to protect your EV:- Move your EV to higher ground: If you're in a flood zone, take your EV to higher ground or evacuate it if possible. This will help prevent it from being submerged in salty water.
- Evacuate early: Be proactive and evacuate before the floodwaters hit. Don't wait for the last minute to move your vehicle to safety.
- After the flood, treat submerged EVs with caution: If your EV has been submerged in water, especially saltwater, it’s essential to avoid using it, charging it, or even moving it until it’s been inspected by professionals. Contact the manufacturer for a thorough inspection of the battery.
- Do not attempt DIY fixes: If your vehicle has been exposed to saltwater, do not try to start it, charge it, or fix the battery yourself. The risks of fire are too high, and professionals are trained to handle such situations safely.