Hybrid Vehicle Fires: The Hidden Risks You Haven't Considered
Why first responders—and vehicle owners—need to understand the unique fire dangers of hybrid vehicles
When most people think about vehicle fire risks, they tend to focus on either traditional gasoline cars or fully electric vehicles. But a recent interview published by Autoblog with transportation risk mitigation expert William S. Lerner sheds light on a critical blind spot: hybrid vehicles present uniquely complicated fire risks that many people—including first responders—may not fully appreciate.
Smaller Batteries Don't Mean Zero Risk
Lerner, a consultant specializing in lithium-ion battery and hydrogen technology safety in transportation, acknowledges that hybrid batteries are smaller than those in full EVs, which generally means a lower fire risk. But that's only part of the story.
He draws an important distinction between mild hybrids and plug-in hybrid electric vehicles (PHEVs). PHEVs pose elevated fire risks because they're regularly plugged in and charged, introducing electrical current from an external charger. According to Lerner, there's roughly a 20-30% chance that a fire-related incident will occur when a vehicle is plugged in, either on the charger side or the vehicle side.
Making matters worse, many PHEV owners ignore manufacturers' recommendations to charge only to 80%. As batteries age—much like the battery in your smartphone—owners tend to charge to 100% more frequently to compensate for diminished range. This habit accelerates degradation and increases the likelihood of thermal issues.
The Dual-Fuel Danger: When Two Fire Types Become One
Perhaps the most eye-opening insight from Lerner concerns the unique dual-fuel danger that hybrids present. Using the 2025 BMW X5 mild hybrid as an example, he explained how space constraints led BMW to position the 48-volt mild hybrid battery in close proximity to the engine and a gas tank made from HDPE plastic—a material that melts at just 348°F.
Here's where it gets alarming: if that 48-volt battery catches fire, it can shoot its cells up to 65 feet and 7 inches. And if the battery fire melts the nearby plastic gas tank, you suddenly have a gasoline fire and a battery fire happening simultaneously.
"By mixing the dual fuels, you're doubling the problem," Lerner said.
The reverse scenario is equally dangerous. If the gas tank fails first, the resulting fire can melt the battery's outer casing, causing the battery to short out—again resulting in two simultaneous fires that require completely different suppression strategies.
A Wake-Up Call for First Responders
This dual-fire scenario creates serious challenges for emergency personnel. A first responder arriving at the scene of a hybrid vehicle fire might instinctively treat it as a standard gasoline fire. But if a live lithium-ion battery is involved, the situation demands an entirely different tactical approach.
Lerner emphasized that hybrid fires can burn at temperatures reaching 5,000°F—dramatically hotter than standard gasoline fires, which typically burn between 1,200°F and 1,500°F. First responders must be mindful that a gasoline tank can purge its entire contents while battery packs can simultaneously project cells at significant distances.
It's About Understanding the Risk, Not Fear
Importantly, Lerner isn't saying that hybrids are inherently more dangerous than gasoline cars or pure EVs. His point is more nuanced: with a hybrid, there's a double chance for something to fail, and when one component fails, it can trigger a cascading failure in the other. That interconnected risk is what makes hybrid fires so uniquely challenging to prevent and suppress.
How FireFibers Can Help
At FireFibers, we understand that lithium-ion battery fires demand specialized solutions. Traditional fire suppression methods alone aren't enough when you're dealing with the extreme temperatures and unpredictable behavior of battery fires—let alone the compounded risks of a dual-fuel hybrid fire scenario.
Our lithium-ion fire blankets are engineered to withstand the extreme heat generated by battery thermal events, helping to contain fires, limit cell ejection, and buy critical time for first responders and bystanders. Whether you're a first responder, a fleet manager overseeing hybrid vehicles, or a homeowner charging a PHEV in your garage, having the right fire suppression tools on hand isn't optional—it's essential.
Don't wait for a dual-fuel fire to catch you off guard. Contact FireFibers today to learn how our lithium-ion fire blankets can protect you, your property, and your loved ones.
FireFibers is a leading provider of lithium-ion fire blankets designed for vehicle, residential, and commercial applications. Stay safe. Stay prepared.
