LIFEPO4 battery site fire safety

[SignatureSolarJames]

NFPA 855 https://www.nfpa.org/codes-and-stan...s/list-of-codes-and-standards/detail?code=855

One thing about ESS systems that is often overlooked is the requirement to keep flammable materials over 4ft away in all directions.

It's not as much about the batteries catching fire (very unlikely and over-protected with redundant measures) as it is about the flammables around it catching fire, e.g. a floor or wood rack catches fire because a wire connection was not torqued with a torque wrench.

If you put enough heat on a LIFEPO4 Pack it will vent gas out of the cells, that gas will light like propane if enough is vented, then you will have to wait as your whole bank burns down. the BMS protections handle internal fires, not external.

This is very unlikely and most people with flammable materials will likely get away scot-free, but regulations are there to make things truly fail-safe.

Hardie Backer and steel are cheap, homes can be pricey.

 

[littleharbor2]

Hardy Backer and steel are cheap, homes can be pricey.

I've seen hardy backer after a fire. It decomposes. Must be the fiber portion of it that fails in intense heat.

 

[SignatureSolarJames]

I've seen hardy backer after a fire. It decomposes. Must be the fiber portion of it that fails in intense heat.

the main thing is that a fire will not start on it

 

[Solar Guy Richard]

the main thing is that a fire will not start on it

This is huge - a fire started in the batteries won't happen because of redundant safety measures, so as long as the material around it won't START a fire you are safe.

 

[Danke]

Answering Frequently Asked Questions About NFPA 855 - GBA Team

What is NFPA 855 and how does it impact owners and their facilities? GBA's team of Mission Critical experts explain the regulations and answer FAQs.

www.gbateam.com

What are the new requirements within NFPA 855?​

Some of the impactful requirements of NFPA 855 include:

Large-scale fire testing shall be conducted on a representative energy storage system (ESS) in accordance with UL 9540A or equivalent test standard.

• This translates into staging a fire for each type, grouping and topology for every planned battery deployment.

The ESS shall be comprised of groups with a maximum stored energy of 50 kWh each and secured against unauthorized entry. Groups are described as enclosures, cabinets and rooms. Each group shall be spaced a minimum of 3 feet from the other groups as well as walls in the area.

• Compared to previous standards, the area required for a battery deployment is larger.

Although the provisions of 855 do not apply to ESS installations that existed or were approved for construction prior to the effective date of the standard, the criterion includes the provision for an authority having jurisdiction (AHJ) to retroactively apply any portions of the standard deemed appropriate.

• In the past, NFPA grandfathered in existing installations. The new standard poses that an AHJ may require the redesign of an installation to meet 855.

Water is considered the preferred agent for suppressing Li-ion battery fires. Water has superior cooling capacity as the battery must been cooled down to help ensure there is no reignition. Lead-acid batteries by example can use different agents in addition to water such as powders, and inert gases.

• The battery groups and deployment must account for the release and dispersal of water so as not to present collateral damage to systems in the area that maintain primary operations.

 

[740GLE]

Li-ion are not LiFePo, can’t compare handling requirements of apples to oranges.

 

[Ampster]

Li-ion are not LiFePo, can’t compare handling requirements of apples to oranges.

Actually Lithium Ion is the general class of batteries containing Lithium ions. There are variations of chemistries, such as Lipo, NMC, LiFePO4 (LFP) and others. LFP is the safest and I agree you cannot compare handling requirements.