Key Takeaways
1. lithium-ion batteries can catch fire even when not plugged in, though it is less common than during charging.
2. Risks arise from internal damage, manufacturing defects, or improper storage (extreme temperatures/moisture), leading to a "thermal runaway" chemical reaction that can cause ignition or explosions, even when sitting idle.
3. How to safely store lithium batteries: keep batteries in a cool, dry place, avoid damage, and handle them properly to minimize risk.
According to the US Consumer Product Safety Commission (CPSC), thousands of thousands of incidents related to lithium battery fires are reported every year.
People are even concerned about, "Can lithium batteries catch fire when not in use?","do lithium ion batteries explode?" or "will lithium batteries leak?". Are you one of them?
Can lithium ion batteries catch fire when not in use? Though it is rare, yes, lithium batteries can pose fire risks under specific conditions, even when they are not in use. Different factors (such as manufacturing defects, improper storage, physical damage, and overcharging) play their part in the occurrence of fire incidents. We will discuss them later in this guide.
What It Means for a Battery to Be "Not in Use"
A lithium battery "not in use" is idle: not charging, not powering any device, and not connected to a load. It’s in storage mode, waiting for future use, off-season, or in your RV.
Even when idle, lithium batteries slowly lose a small percentage of charge over time, a normal process called self-discharge. This is due to internal chemical reactions and is expected for all rechargeable batteries.
Self-discharge doesn’t cause fires, but proper storage and safe handling remain important to maintain battery health and safety.
Do Lithium Batteries Pose a Fire Risk When Not in Use?
Lithium batteries can catch fire even when not in use, though the risk is lower if unplugged. The main danger is thermal runaway, which occurs if cells overheat due to defects, damage, or extreme heat. Temperatures over 150°C can cause uncontrollable energy release, leading to fire, smoke, or explosion.
How to safely store lithium batteries: keep batteries in a cool, dry place, avoid damage, and handle them properly to minimize risk.
In short, unused lithium batteries are generally safe but not risk-free. Proper storage and careful handling are essential to prevent fire hazards.
Causes of Lithium Battery Fires During Storage
While lithium batteries are generally safe, fires can occur under certain conditions. The main causes are internal faults, external damage, and improper storage.
1. Internal Factors
About 25% of lithium battery fires stem from internal issues such as manufacturing defects or internal short circuits. Impurities or poor-quality separators can trigger thermal runaway, even when the battery is not in use. Proper quality control during manufacturing is crucial to reduce this risk.
2. External Factors
Physical damage from crushing, punctures, or drops, as well as exposure to extreme temperatures, can destabilize batteries. Heat above 130°C or prolonged cold can accelerate chemical degradation, while moisture may corrode internal components, all increasing fire risk.
3. Improper Storage
Incorrect storage can shorten battery lifespan and increase fire risk. Avoid stacking batteries tightly and keep them away from metal objects or flammable materials to prevent short circuits. Recent incidents, like the January 2025 fire at the Vistra Energy Storage Facility, highlight the importance of safe storage practices.
How To Safely Store Lithium Batteries
Lithium batteries are safe when stored and handled properly. Poor storage or mishandling can create risks. Follow these tips to ensure safety and extend battery life.
1. Best Storage Practices
Store batteries in a cool, dry place away from heat sources and direct sunlight. Avoid humid environments to prevent corrosion. Modern fireproof bags and protective cases can prevent short circuits, punctures, and damage. Learn more storage guidelines.
2. Charging Instructions
Use only manufacturer-approved Battery Chargers suited for your battery. Unplug once fully charged, avoid charging in extreme temperatures, and keep away from flammable materials.
3. Safe Disposal and Recycling
Do not throw failed or damaged batteries in household trash. Wrap each battery in non-conductive material and dispose of it via certified recycling programs. Learn how to recycle lithium batteries.
4. Choose Trusted Brands
Buy from certified brands with built-in safety features, such as BMS protection and self-heating. For example, the Renogy Pro S1 12V 240Ah LiFePO4 Battery safeguards against overheating, over-discharging, and overcharging, making it reliable for RV, off-grid, and solar setups.
What to Do If a Battery Shows Warning Signs?
Though lithium batteries fail rarely, it is important to act fast if you notice any warning signs. The potential warning signs are as follows.
- A chemical-like, foul, sharp smell
- Unusual heat or melting plastic
- Popping or hissing sounds
- Sparks or smoke
- Bulging or swelling on the battery case
If you notice any of the above-mentioned signs, take immediate action, as listed below.
- Ensure personal safety by evacuating the affected area immediately.
- Don't use water to stop the battery fire. Instead, you can use a Class D fire extinguisher for small lithium batteries. You can also use dirt or sand to stop flames.
- Call emergency services for professional and timely assistance.
Once the incident happens, never repair or reuse the damaged battery. Instead, place it in a non-conductive container and take it to a certified recycling or waste facility for safe and proper disposal.
Frequently Asked Questions
Can a lithium battery catch fire when not being charged?
Yes, your lithium batteries can be at risk, even when they are not being charged. However, it is rare, as mentioned in the discussion above. The risk of catching fire usually increases with improper storage, internal defects, or damage. Proper storage and safe handling greatly reduce the chances of fire or thermal runaway.
Is it safe to keep a lithium battery in the house?
If you keep your lithium battery away from flammable materials and direct sunlight, and store it in a dry, cool place, it is absolutely safe to keep indoors. If you want to add extra protection to avoid any sort of inconvenience, use battery safety bags or fireproof storage containers.
Should you remove lithium batteries when not in use?
Yes, it is a good practice to remove your battery from all devices if it is not in use. Doing this helps you reduce the chance of the battery catching fire or undergoing thermal runaway. Make sure the battery is partially charged before you store it in a cool, dry place. It will preserve its health and maximize safety.
How long can a lithium battery sit unused?
Well, it all depends on how they are stored. If you have stored your lithium battery properly, it can sit idle or unused for a couple of months to one year. Remember, lithium batteries undergo self-discharge naturally; therefore, recharging and periodic checks are recommended.
What Causes Lithium ion Batteries To Swell
Lithium-ion batteries swell due to internal gas buildup caused by decomposing electrolytes, a byproduct of aging, overheating, or overcharging. These gases (such as and hydrogen) get trapped inside the sealed pouch, causing it to bulge.
Final Thoughts
Lithium batteries are reliable and efficient, but they need safe storage and careful handling like all other energy devices. It is true that lithium batteries can catch fire, but it is rare. In most cases, fires are preventable. If you want to get the maximum out of your lithium batteries, ensure you use manufacturer-approved chargers, store them in a cool, dry place, and always respond quickly to warning signs.
Renogy AU prioritizes safety and offers lithium batteries with modern Battery Management Systems (BMS) protection to prevent issues like fire risks, overheating, and overcharging. Whether you want to power an off-grid system, an RV, or a solar setup, you can always count on Renogy batteries, as they deliver both safety and performance.
