Manage Storage of Lithium-Ion Vehicle Batteries?

4/28/2021

What are your recommendations for fire safety of single height storage of Lithium-ion vehicle batteries?

Currently in our warehouse, in a sprinklered covered area, we are storing 3 to 5 of these lithium-ion batteries before they are sent to dealerships. We have security guards take 1-hour temperature readings throughout the day and night but little else has been put in place and a proper fire risk assessment has not been performed. Thanks in advance.

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8 Comments

Mike

4/28/2021 08:27:01 am

I am working on a massive project where there are massive quantities of these types of batteries being manufactured, stored and used. The owner had a Fire Protection Engineer prepare a risk assessment.

Consultants are quite expensive and maybe the AHJ will have their own requirement.

Thomas

4/28/2021 08:31:03 am

What design density? How high?

Dan Wilder

4/28/2021 08:44:03 am

NFPA 855 has a little guidance available.

Here is a list of NFPA links to their research
https://www.nfpa.org/ess

with this report being specific to sprinkler protection...
https://www.nfpa.org//-/media/Files/News-and-Research/Fire-statistics-and-reports/Suppression/RFESSSprinklerProtection.pdf

However, as Mike said above, these are emerging technologies and hiring a FPE to create a report taking into account what the building is doing for both active & passive protection (rated walls, containment, detection) in addition to providing sprinkler related protection design criteria will be your (the owners) best option.

CJ Bonczyk

4/28/2021 09:17:22 am

I agree with Dan. We have had these facilities pop up all over Texas. Many times the information regarding the storage layout, height, if they are contained or not, all needs to be long thought out prior to the sprinkler design and water availability. Currently NFPA 855 2020 is your go to for now. Hiring an FPE and heavy coordination with the AHJ must happen to properly CYA. We have had to use certain clean agents, revise storage and add cut off spaces. The water usage to suppress a fire of these type is immense. A single instance here in Texas involved a Tesla car that the batteries caught fire and majority of the damaged was caused in the first 10 minutes from the batteries and chain reaction and just to put the car fire out required almost 30k gallons of water.

4.11.2.1 Sprinkler systems for ESS units (groups) with a maximum stored energy of 50 kWh, as described in 4.6.2, shall be designed using a minimum density of 0.3 gpm/ft² based over the area of the room or 2500 ft² design area, whichever is smaller, unless a lower density is approved based upon large-scale fire testing in accordance with 4.1.5.

4.11.2.2* Sprinkler systems for ESS units (groups) exceeding
50 kWh shall use a density based on large-scale fre testing in
accordance with 4.1.5.

A.4.11.2.2 UL 9540A Installation Level Test, Method 1,
provides the data needed to determine if automatic sprinkler
design densities can be changed. A sprinkler density in excess
of 0.3 gpm/ft² can be necessary to provide an adequate level of protection, especially for some lithium-ion battery ESS designs. However, test results for some ESS designs and technologies indicate sprinkler densities less than 0.3 gpm/ft² could be acceptable. Equivalent test standards, as permitted in 4.1.5, might provide comparable data.

Ventilation during suppression is critical. Research has
shown that Li-ion batteries might continue to generate flammable gases during and after extinguishing. In addition, testing has shown that during sprinkler suppression, removal of
combustion and flammable gases emitted from the battery
significantly improves the effectiveness of the suppression.

Franck

4/28/2021 09:35:50 am

There is a difference when the batteries are being used (ESS) and then you can apply NFPA 855 (0.3 gpm/ft² based over the area of the room or 2500 ft²) and storage of batteries that are not being used (such as big storage facility).

In the case of storage of large quantities of lithium-ion batteries, the commodity classification should be considered as unexpanded plastic.
When stored in cardboxes, the classification is unexposed unexpanded plastic, and when no packaging material is present, it should be considered as exposed unexpanded plastic.

Lithium-ion batteries kept in storage area should not be charged at more than 50% of their full capacity. 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.

The storage area should be kept at a temperature between 4 and 27°C (40-80°F) to limit the risk of thermal runaway from manufacturing defects or internal failures.

Franck

4/28/2021 09:39:12 am

If batteries (lithium ion) are being used, then you may consider the following.

To date there is no publicly available test data that confirms the effectiveness of any active fire protection for energy storage systems. Automatic sprinkler protection is recommended to limit fire spread to the surrounding structure, equipment, and building contents. See NFPA 855 for more details.

If a Li-ion battery overheats, hisses or bulges, the device should immediately be moved away from flammable materials and place it on a non-combustible surface.
If at all possible, the battery should be removed and put it outdoors to burn out. Simply disconnecting the battery from charge may not stop its destructive path.

For the most part, a lithium-ion battery fire can at best be cooled, contained and suppressed. Extinguishing a lithium-ion battery fire with 100% certainty is not always possible due to the unpleasant issue of thermal runaway.
Lithium-ion battery fires do not require oxygen to burn and can be considered by nature a chemical fire.

A small Lithium-ion fire can be handled like any other combustible fire.
For best result use a foam extinguisher, CO2, ABC dry chemical, powdered graphite, copper powder or soda (sodium carbonate).
A small module on fire can also be immersed into water. Water-based products are most readily available and are appropriate since Lithium-ion contains very little lithium metal that reacts with water. Water also cools the adjacent area and prevents the fire from spreading. Research laboratories and factories also use water to extinguish Li-ion battery fires.

For larger fires, specific extinguishers approved for lithium-ion battery fires, such as Lith-Ex extinguishers, should be used.
The portable fire extinguishers can be used for batteries installed inside equipment (mobile phones, tablets…) and where batteries are stored and/or are under charge.

Note that general class D extinguishers can normally only be applied to a flat surface as the extinguishant has no ability to adhere to vertical or other angular surfaces.
Copper based class D units, which are designed to cling to vertical surfaces, are also ineffective on lithium battery fires.
In the case of lithium-ion battery fires, these extinguishing agents have no ability to cool cells in order to prevent the propagation of the fire throughout a module.

A large Li-ion fire, such as in an Electrical Vehicle, may need to burn out. Water with copper material can be used. Using water even with large Li-ion fires is advisable as water lowers combustion temperature . But is not recommended for battery fires containing lithium-metal.

Franck

4/28/2021 09:40:16 am

Safety precautions
A safe separation distance should be maintained between battery charging stations and any combustible materials.
The minimum separation distance should be 0.9 m (3 ft) for large format batteries charging station and 0.3 m (1 ft) for small format batteries (such as the one used in tools).
Battery docking/charging stations should be positioned on a flat non-combustible surface.

As for any battery charger in storage areas, battery chargers for very large Lithium-ion batteries should be surrounded with a barrier which prevents any storage less than 1.5 m (5 ft) away.

Any Lithium ion battery with external visible damage should be replaced and the waste battery disposed in a dedicated waste bin. The internal integrity of a battery (components and mechanisms) is susceptible to high damages when subjected to external forces or dropped on a hard surface/ground.

Franck

4/28/2021 09:42:32 am

Used/damaged battery disposal
Battery terminals should be isolated (covered by insulation material) before disposal. This would prevent any accidental contact with metal or other battery contact that would close the battery circuit and result in energy discharge.
Batteries with physical or mechanical damages should be stored separately from other batteries.

A safe separation distance of at least 3 m (10 ft) should be provided between disposal of damaged/waste/discarded batteries and bins filled with other combustible material, or any combustible material.
Waste disposal bins for lithium-ion batteries should be made of metal (no plastic) and equipped with a metal lid.

Note that all the precautions listed in my comments are recommended best practices for lithium batteries. This not directly coming from a specific standard (but based on several sources of information).
To be adapted to you needs/point of view.

Manage Storage of Lithium-Ion Vehicle Batteries?

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