The hidden fire danger in every home

This Fire Prevention Week, as families across San Mateo County check smoke alarms and review escape plans, we’re highlighting the hidden fire danger that’s everywhere: the batteries powering our modern lives.

The National Fire Protection Association didn’t choose “Charge Into Fire Safety” as this year’s theme by accident. In 2023 alone, at least 1,600 incidents, 611 injuries, and 115 fatalities were linked to lithium-ion battery fires nationwide. Fire services report a 46% increase in these fires, with a 93% spike between 2022 and 2024.

Why battery fires are different

As fire professionals, we use the Fire Triangle — fuel, heat and oxygen — to understand how fires start and spread. But battery fires break this fundamental rule in dangerous ways.

Traditional fires need oxygen from the air around them, which is why you can smother a candle flame. Battery fires are terrifying because they generate their own oxygen while burning, making them self-sustaining. Even more dangerous, water can’t extinguish these fires — it actually makes them worse by generating flammable hydrogen gas.

When a lithium-ion battery enters “thermal runaway” — a chain reaction when overheating causes catastrophic failure — it becomes a fire factory that releases toxic gases and burns at extreme temperatures. EV fires burn at 5,000°F compared to gas fires at 1,500°F, and require 10 times more water to extinguish than traditional fires.

Everyday devices creating risk

The most concerning trend we’re seeing involves common household items. E-bikes, scooters and hoverboards are most commonly involved in fires, but laptops, cellphones, tablets and power tools are close behind. In 2024, e-bikes accounted for 362 of the 1,330 lithium-ion fires tracked.

Perhaps most surprising: 56% of battery fire devices weren’t even charging when they failed. This means damaged or defective batteries can become fire hazards any time, not just during charging.

Simple prevention saves lives

The good news is that battery fire prevention follows straightforward rules that every family member can learn and practice.

• Charge smart: Use only the original manufacturer’s chargers and charge devices on hard surfaces — never on beds, couches, or soft materials that trap heat. Unplug devices when fully charged to prevent dangerous overheating.

• Store smart: Keep e-bikes and scooters away from doors, windows and stairways. If a battery fire starts, you need clear escape routes. Store these devices outdoors when possible.

• Watch for warning signs: Unusual smells, color changes, excessive heat, swelling, leaking or smoking are all danger signals. Stop using the device immediately and remove it from your home.

• Dispose properly: Never throw lithium-ion batteries in regular trash. They can ignite during handling or transport. Use designated battery recycling locations instead.

Why this matters for our community

California leads the nation in battery fire risks. The recent January 2025 Los Angeles wildfires left behind more than 1 million pounds of damaged lithium-ion batteries —16 times more than the Maui wildfires. Monterey County’s Moss Landing battery storage facility fire forced evacuation of 1,500 residents. In Los Angeles County alone, 99,000 zero-emission vehicles were sold in 2024, and California’s Recycling Agency reports batteries are already the leading cause of fires at state waste facilities.

Beyond individual safety

Battery fire prevention connects to our broader emergency preparedness philosophy: individual actions strengthen our entire response system. When families eliminate preventable fire risks in their homes, it frees up firefighters to focus on the wildfires, earthquakes, and other hazards we can’t prevent.

This Fire Prevention Week, we’re asking every San Mateo County family to take one simple action: walk through your home and identify every device with a lithium-ion battery. Count them — phones, tablets, laptops, e-bikes, power tools, even some smoke detectors. Then commit to following the charging and storage safety rules that can prevent your family from becoming part of these alarming statistics.

The devices that make our lives more convenient shouldn’t make our homes more dangerous. With basic awareness and simple precautions, we can enjoy the benefits of modern technology while keeping our families and community safe.

For battery recycling locations near you, visit www.call2recycle.org.

Mark Lorenzen is chief of the Menlo Park Fire Protection District and Dr. Shruti Dhapodkar is the director of San Mateo County Emergency Management.