8 Charging Mistakes That Increase Lithium Battery Fire Risk

Lithium-ion batteries power some of the most exciting personal electric vehicles on the market: electric unicycles, e-bikes, electric scooters, and more. But the same energy density that makes them so capable also makes charging habits critically important. Most lithium battery fires don't come out of nowhere. They're the result of avoidable mistakes made during charging. Jerry Bloodworth lost a three-car garage and two vehicles to a lithium scooter fire, despite doing many things right. His story is worth reading before you get to the list below.

Here are eight of the most common ones, and what to do instead.

Mistake 1: Charging Unattended (Especially Overnight)

The mistake: Plug in, go to sleep, assume the battery management system (BMS) will handle everything.

Why it's risky: If a failure occurs during the constant-current phase (early charging) or the voltage taper phase (near full charge), you won't notice the early warning signs: odor, excess heat, or light smoke. Lithium-ion failures escalate quickly, and time matters.

Safer practice:

• Stay nearby during the first 20–30 minutes of charging

• Avoid charging while asleep

• Use a smart plug with an auto shutoff timer

• Charge during hours you're awake and alert

"Not charging unattended, being present when devices are charging, is a big thing." — Shane Bentley, Co-Founder, FCL-X

Mistake 2: Using the Wrong Charger

The mistake: Using a charger from another device, an aftermarket high-amp "fast charger," a modified charger, or a cheap online replacement.

Why it's risky: Incorrect voltage or amperage can overstress cells, overheat wiring, and bypass BMS expectations. Overvoltage is one of the fastest ways to trigger internal instability.

Safer practice:

• Use the manufacturer-approved charger

• Match voltage exactly

• Avoid boost charging unless your pack is specifically rated for it

• Inspect your charger brick regularly for signs of overheating

Mistake 3: Charging Near Flammable Materials

The mistake: Charging next to cardboard boxes, gas cans, wood shelving, fabric, foam, or stored gear.

Why it's risky: Even a contained battery event can ignite surrounding materials, and that's usually what turns a manageable situation into a total loss. Most garage fires that start with a lithium battery spread because of what's nearby, not just the battery itself.

Safer practice:

• Charge on a concrete or steel surface

• Maintain 12–24 inches of clearance between devices

• Keep a 3-foot clear zone around the charging area

Mistake 4: Ignoring Physical Damage

The mistake: Continuing to charge after a crash, a drop, water exposure, or a visible dent in the casing.

Why it's risky: Internal cell damage may not show immediately. Separator damage can create delayed internal short circuits. Thermal runaway can occur hours or even days later during a routine charge.

Safer practice:

• Inspect thoroughly after any hard impact

• If unsure, isolate the battery and observe it before charging again

• Never charge a swollen or visibly dented pack

"Thermal runaway can occur hours or days later. Just because you stopped it doesn't mean there's not potential energy still stored." — Shane Bentley, Co-Founder, FCL-X

Mistake 5: Fast Charging High-Capacity Packs Frequently

The mistake: Constantly charging at maximum amperage for convenience.

Why it's risky: Fast charging increases internal resistance stress, raises internal temperatures, and accelerates cell degradation over time. Degraded cells are statistically more failure-prone and harder to predict.

Safer practice:

• Use standard charge rate for routine, day-to-day charging

• Reserve fast charging for when you actually need it

• Allow the battery to cool before and after charging

Mistake 6: Charging in Extreme Temperatures

The mistake: Charging in a freezing garage in winter or a hot garage above 95°F (35°C) in summer.

Why it's risky: Cold charging can cause lithium plating, a condition where metallic lithium deposits on the anode and creates internal short-circuit risks. Hot charging increases internal instability and accelerates breakdown.

Safer practice:

• Charge between approximately 50–85°F (10–30°C)

• Allow the battery to reach room temperature before charging if it's been stored in the cold or heat

Mistake 7: Leaving Batteries at 100% for Extended Periods

The mistake: Charging to 100% and storing the device that way for days or weeks.

Why it's risky: High state-of-charge increases electrolyte stress and internal chemical reactivity. Over time, this degrades the pack faster, and a degraded pack carries a higher failure probability.

Safer practice:

• Store long-term at 40–60% charge

• Only charge to 100% when you're planning to ride soon

Mistake 8: Daisy-Chaining Chargers on a Single Outlet

The mistake: Running multiple chargers off one outlet through cheap extension cords or power strips.

Why it's risky: Overloaded circuits, heat buildup in cords, and loose plug connections are all hazards on their own. Combined with high-draw lithium chargers, they significantly increase the risk of an electrical fire. Electrical fires and battery fires together are extremely difficult to manage.

Safer practice:

• Dedicate a circuit to your charging area if possible

• Use a heavy-gauge extension cord rated for the load

• Never stack multiple chargers on a single cheap power strip

One More Layer of Protection

"The education is far more valuable than the extinguisher that they're buying." — Shane Bentley, Co-Founder, FCL-X

Good charging habits eliminate the majority of lithium fire risk, but not all of it. Batteries fail. BMS units fail. Damage isn't always visible. For riders with high-capacity packs (and the four- and five-figure investments that come with them), having a lithium-specific fire extinguisher on hand is the last line of defense that actually works.

Standard ABC dry powder extinguishers and water won't stop a lithium thermal runaway, and in some cases can make it worse. We went deep on why with FCL-X co-founder Shane Bentley in Why Most Fire Extinguishers Won't Save Your EUC, Onewheel, or E-Bike. FCL-X is a UL-listed, water-based suppression agent engineered specifically for lithium-ion battery fires. We carry it at eRideLife because we believe every serious rider should have one within reach of their charging area.

Explore lithium fire safety products at eRideLife →

Safety Disclaimer: This article is for educational purposes only. In any fire emergency, call 911 immediately. Only attempt to suppress a fire if it is small, you have a clear and unobstructed exit behind you, you are not exposed to toxic gases, and you have the correct equipment. Never place yourself or others at risk to save property. If conditions are unsafe or the fire is growing beyond your control, evacuate immediately and leave firefighting to the professionals.