Why have lithium-ion batteries become so popular?

They have a higher energy density than other rechargeable batteries. They are also available at a low cost per energy and hold their charge a lot better.

What are the fire hazards associated with lithium-ion batteries?

They are relatively easy to damage because of the plastic casings and may overheat with heavy power draws. They are equipped with a flammable electrolyte which is ether-based and has a very low flash point. Plus, the technology is rapidly evolving. Codes and standards have not caught up yet.

Do you need Class D extinguishers for metal fires to put out a lithium-ion fire?

There is no need for Class D extinguishers. Rechargeable lithium-ion batteries don’t have solid elemental lithium in them. There is a lithium oxide anode, but it is not pure lithium metal. It’s already been oxidized so it can’t really burn. Foam or water are just fine.

What are the main causes of lithium-ion battery failure?

Common causes of lithium-ion battery fires include incorrect charging equipment, overcharging the battery pack or cell, mechanical damage, and short circuits.

What are best practices for safely discarding lithium-ion batteries?

There’s still a residual charge inside batteries even though they may not be usable. If not handled properly, they can cause fire. Take these actions to prevent fire: Wrap terminals in electric tape and cover with plastic caps Store in a metal container with a lid Store outside if possible If they are inside, keep them away from other combustibles and near exits. If you see any signs of thermal runaway, quickly remove them from your facility

What are best practices for safe lithium-ion battery storage?

In the absence of NFPA standards, we recommend taking the following safe storage actions: Store batteries at 30% or less charge . Batteries that have a low charge level are much less susceptible to spontaneous ignition. Separate batteries from combustibles . Makes sure you have 10 feet of separation from other combustibles and store in another area if possible. Don’t store anything above lithium-ion storage racks . Since vapor rises from a damaged or punctured battery, be sure not to store anything over top of them. Provide sprinkler protection . Sprinklers help control a fire. Use ESFR sprinklers per requirements for unexpanded plastic commodities. They keep it cool and keep it from spreading. Don’t store higher than 15 feet . If you store above that height, you will need additional protection other than ceiling sprinklers.

How do storage best practices change for larger batteries?

Fire testing on large lithium-ion batteries has been sparse, but some general rules apply. Store them outside when practical. Provide at least three feet between containers and store at least 50 feet from building openings. No more than 600kWh in a group and at least 10 feet between groups. And keep them at 30% charge. If you’re storing inside use ESFR sprinkler protection. Put them near exterior doors.

What are safe battery charging best practices?

Don’t charge on flammable surfaces like wood. Use non-combustible material instead. Have any combustibles at least 18 inches away from the charger. You don’t want thermal runaway near heat sources.

What does a robust fire emergency response plan look like?

Lithium-ion battery fires are very difficult to extinguish. As the fire burns, cells rupture – leading to the release of more flammable vapor, and more fire. Be patient. You may have to let the fire burn out and wait until all the energy is discharged. Beware, it may look like the fire is out, but it can reignite as breached cells are met with oxygen. Don’t shut off your sprinkler system prematurely. If batteries have been heated to 130-150˚ Fahrenheit, they are subject to spontaneous ignition. If possible, move burning batteries out of the building to a safe burnout area. Also, explore encapsulating agents which have shown promise in testing. The fire is not out until all batteries involved in the fire or near the fire area have been removed from the building.

Is foam better than water for fighting lithium-ion fires?

Not really. It tends to coat the batteries making it slightly harder for vapor to release, but it can give you a false sense of security.

How do insurance property underwriters view lithium-Ion battery exposures?

Without standards, underwriters tend to be risk averse. Underwriters want to see you taking proactive steps for lithium-ion battery safety such as minimizing the charge, separating batteries, storing outside, safe discarding practices, and taking actions to reduce loss.

Is it safe to have an electric vehicle (EV) charger in the basement of your building?

The potential damage from an EV fire in the basement is essentially the same as it is for a gasoline powered vehicle.

If damage is such a concern, why has the industry not changed to more durable construction?

Because everything is a trade-off. More durable construction increases cost – and cost is a major driver for battery manufacturers.

Are there temperature ranges for storage or for batteries in service?

We advise that you follow the recommendations of the battery manufacturer.

Lithium-Ion Battery Storage & Handling

Safe Storage Reduces Lithium-Ion Battery Fire Risks

Lithium Ion Battery Storage From smartphones to laptops to wearables, lithium-ion batteries power our world. They have greater energy density, higher voltage per cell, and hold charge better than other rechargeable batteries.

But they are prone to spontaneous ignition when damaged or overloaded. That results in explosions and fires that are difficult to extinguish. If not handled properly, the event can cause major property damage and serious injuries. Lithium-ion battery fire risks exist in facilities that manufacture batteries, warehouses that store them, and facilities that use them.

TÜV SÜD Risk Consulting offers comprehensive risk analysis and prevention services to mitigate this growing risk. For facilities that use lithium-ion batteries in industrial applications, or facilities that bulk store or recycle lithium-ion batteries, our expert engineers can help drastically reduce the risk of fire and explosions.

Lithium-Ion Battery Fire Hazards

More Power + Flammable Components - With greater energy density and cell voltage comes more power. The flammable electrolyte is 3% to 15% by weight. The larger the cells, the more electrolyte is present.

Plastic Cell Casings - Cell casings can be easily breached, leading to the release of flammable electrolyte vapors.

Ignition Source Included - A heat source is already present from high current draw.

Difficult to Extinguish - Water cannot reach interior cells to cool them. As each cell wall fails, it releases more flammable electrolyte that is ignited by the existing fire, so fires can last a long time regardless of firefighting actions.

Causes of Lithium-Ion Battery Failure

There are multiple reasons that lithium-ion batteries fail and subsequently become fire risks:

Overcharging - Always use the charger designed for the specific battery.

Excessive Discharge Current (Short Circuit) - Always use the battery specified for a particular piece of equipment.

Mechanical Damage - Be careful not to drop batteries or puncture them. Carefully discard obviously damaged batteries.

Faulty Manufacture/Construction - This is becoming less of a problem as manufacturing quality improves.

How to Safely Discard Lithium-Ion Batteries

DISCARD LITHIUM-ION BATTERIES A residual charge can still generate the ignition source and breach cell walls to release electrolyte vapor. Be sure to wrap terminals in electric tape or cover with plastic caps.

When storing discarded batteries, place them in a metal container with a lid. Store outdoors, if practical. If indoors, ensure 3 meters (10 feet) of separation to other combustibles or exit pathways. Store them near an exterior door if practical.

How to Minimize Lithium-Ion Fire Risks

Operators of industrial facilities can reduce fire and explosion risks associated with lithium-ion batteries. Here are some practical steps:

Ensure the facility is equipped with sprinklers conforming to NFPA 13 standards for unexpanded plastic materials. Large scale testing has shown that small format lithium-ion batteries in storage behave similarly to unexpanded plastic commodities in a fire.
Make sure lithium-ion batteries held in storage are charged at levels not exceeding 50% of their charge capacity – and preferably 30%. Fully charged lithium-ion batteries have a higher energy density and are at greater risk of generating significant heat from short circuiting related to internal defects.
Establish minimum distances between battery charging stations and any combustible materials.
Carefully discard lithium-ion batteries that show evidence of physical or mechanical damage.
Create a fire emergency response plan. Remember extinguishing agents may put the fire out initially but not cool the fire or eliminate an internal short circuit, meaning it may re-ignite. You may need to let the fire burn out. Do not consider the fire to be out until all batteries in the fire or near the fire area have been removed from the building.

Trust TÜV SÜD Risk Consultants for Energy Storage Protection

During a risk analysis, expert engineers at TÜV SÜD will uncover any hidden risks of fire and explosion from energy storage. We will analyze your storage processes and find problems with thermal runaway or ways you might be damaging battery assemblies. Then we will help develop robust plans for proper storage to minimize potential problems before they start.

FAQs On Lithium-Ion Battery Fires

The below FAQs were developed by expert engineers who have helped large and small businesses manage their lithium-ion battery fire risks.

Why have lithium-ion batteries become so popular?

They have a higher energy density than other rechargeable batteries. They are also available at a low cost per energy and hold their charge a lot better.
What are the fire hazards associated with lithium-ion batteries?

They are relatively easy to damage because of the plastic casings and may overheat with heavy power draws. They are equipped with a flammable electrolyte which is ether-based and has a very low flash point. Plus, the technology is rapidly evolving. Codes and standards have not caught up yet.
Do you need Class D extinguishers for metal fires to put out a lithium-ion fire?

There is no need for Class D extinguishers. Rechargeable lithium-ion batteries don’t have solid elemental lithium in them. There is a lithium oxide anode, but it is not pure lithium metal. It’s already been oxidized so it can’t really burn. Foam or water are just fine.
What are the main causes of lithium-ion battery failure?

Common causes of lithium-ion battery fires include incorrect charging equipment, overcharging the battery pack or cell, mechanical damage, and short circuits.
What are best practices for safely discarding lithium-ion batteries?
There’s still a residual charge inside batteries even though they may not be usable. If not handled properly, they can cause fire. Take these actions to prevent fire:
- Wrap terminals in electric tape and cover with plastic caps
- Store in a metal container with a lid
- Store outside if possible
- If they are inside, keep them away from other combustibles and near exits.
- If you see any signs of thermal runaway, quickly remove them from your facility
What are best practices for safe lithium-ion battery storage?
In the absence of NFPA standards, we recommend taking the following safe storage actions:
- Store batteries at 30% or less charge. Batteries that have a low charge level are much less susceptible to spontaneous ignition.
- Separate batteries from combustibles. Makes sure you have 10 feet of separation from other combustibles and store in another area if possible.
- Don’t store anything above lithium-ion storage racks. Since vapor rises from a damaged or punctured battery, be sure not to store anything over top of them.
- Provide sprinkler protection. Sprinklers help control a fire. Use ESFR sprinklers per requirements for unexpanded plastic commodities. They keep it cool and keep it from spreading.
- Don’t store higher than 15 feet. If you store above that height, you will need additional protection other than ceiling sprinklers.
How do storage best practices change for larger batteries?

Fire testing on large lithium-ion batteries has been sparse, but some general rules apply. Store them outside when practical. Provide at least three feet between containers and store at least 50 feet from building openings. No more than 600kWh in a group and at least 10 feet between groups. And keep them at 30% charge. If you’re storing inside use ESFR sprinkler protection. Put them near exterior doors.
What are safe battery charging best practices?

Don’t charge on flammable surfaces like wood. Use non-combustible material instead. Have any combustibles at least 18 inches away from the charger. You don’t want thermal runaway near heat sources.
What does a robust fire emergency response plan look like?

Lithium-ion battery fires are very difficult to extinguish. As the fire burns, cells rupture – leading to the release of more flammable vapor, and more fire. Be patient. You may have to let the fire burn out and wait until all the energy is discharged. Beware, it may look like the fire is out, but it can reignite as breached cells are met with oxygen. Don’t shut off your sprinkler system prematurely. If batteries have been heated to 130-150˚ Fahrenheit, they are subject to spontaneous ignition. If possible, move burning batteries out of the building to a safe burnout area. Also, explore encapsulating agents which have shown promise in testing. The fire is not out until all batteries involved in the fire or near the fire area have been removed from the building.
Is foam better than water for fighting lithium-ion fires?

Not really. It tends to coat the batteries making it slightly harder for vapor to release, but it can give you a false sense of security.
How do insurance property underwriters view lithium-Ion battery exposures?

Without standards, underwriters tend to be risk averse. Underwriters want to see you taking proactive steps for lithium-ion battery safety such as minimizing the charge, separating batteries, storing outside, safe discarding practices, and taking actions to reduce loss.
Is it safe to have an electric vehicle (EV) charger in the basement of your building?

The potential damage from an EV fire in the basement is essentially the same as it is for a gasoline powered vehicle.
If damage is such a concern, why has the industry not changed to more durable construction?

Because everything is a trade-off. More durable construction increases cost – and cost is a major driver for battery manufacturers.
Are there temperature ranges for storage or for batteries in service?

We advise that you follow the recommendations of the battery manufacturer.