LFP safety and "lithium battery fires"

[IanD]

Here's a letter about LFP safety from the president of ABYC, the American boating association who set safety standards used by boatbuilders and insurers:

 

https://diysolarforum.com/threads/letter-from-abyc-president-re-lifepo4-safety-on-boats.48022/

 

Here are some selected quotes, for those who don't want to read the full letter or the comments on it... 😉 

 

"The ABYC Technical Department, with input from the industry, recreated a number of scenarios based on accident narratives that claimed LiFePO 4 batteries to be the cause of a fire. In our on-site test lab, our team subjected batteries to conditions ranging from “normal” operations to extreme use and abuse. We purchased units built for the marine environment with robust battery management systems. We also included recycled batteries available from mass retailers, with an “optional” battery management system and no clear instructions from the battery or cell manufacturer. We tried to replicate sketchy behavior which is the fear of insurance companies and regulators alike.

 

Do you know what we found? We couldn’t start the fire (Sorry Billy Joel). We witnessed swollen cells, completely dead batteries, and multiple safety cutoffs (when not bypassed). We had a very hot summer here in MD. Even the high heat didn’t come close to a spontaneous combustion scenario.

 

We arranged calls with industry experts, and we asked them what we might be missing in our testing. What can we throw at these batteries to replicate the accidents we were hearing about? No one had anything to add, short of putting these batteries directly in a fire (which we did). We were able to add LiFePO 4 batteries to a local International Association of Arson Investigators (IAAI) boat burn--even there, no one detected any indication that the batteries themselves contributed to the fire." 

 

 

Edited September 19, 2025 by IanD

[MtB]

4 hours ago, IanD said:

Here's a letter about LFP safety from the president of ABYC, the American boating association who set safety standards used by boatbuilders and insurers:

 

https://diysolarforum.com/threads/letter-from-abyc-president-re-lifepo4-safety-on-boats.48022/

 

Here are some selected quotes, for those who don't want to read the full letter or the comments on it... 😉 

 

"The ABYC Technical Department, with input from the industry, recreated a number of scenarios based on accident narratives that claimed LiFePO 4 batteries to be the cause of a fire. In our on-site test lab, our team subjected batteries to conditions ranging from “normal” operations to extreme use and abuse. We purchased units built for the marine environment with robust battery management systems. We also included recycled batteries available from mass retailers, with an “optional” battery management system and no clear instructions from the battery or cell manufacturer. We tried to replicate sketchy behavior which is the fear of insurance companies and regulators alike.

 

Do you know what we found? We couldn’t start the fire (Sorry Billy Joel). We witnessed swollen cells, completely dead batteries, and multiple safety cutoffs (when not bypassed). We had a very hot summer here in MD. Even the high heat didn’t come close to a spontaneous combustion scenario.

 

We arranged calls with industry experts, and we asked them what we might be missing in our testing. What can we throw at these batteries to replicate the accidents we were hearing about? No one had anything to add, short of putting these batteries directly in a fire (which we did). We were able to add LiFePO 4 batteries to a local International Association of Arson Investigators (IAAI) boat burn--even there, no one detected any indication that the batteries themselves contributed to the fire." 

 

 

 

 

None of which addresses the assertion being made about the ABC day boat conflagration, namely that the LFP batteries exploded.

[David Mack]

That letter is from September 2022 - three years ago. A formal report was promised, to be submitted to US Coastguard. Do you know if that report has been published?

[NB Saturn]

6 hours ago, David Mack said:

That letter is from September 2022 - three years ago. A formal report was promised, to be submitted to US Coastguard. Do you know if that report has been published?

 

There’s the attached, but again it promises a full report in “due course”. I’ve emailed their Tech team to enquire about it (it may be restricted to members), I’ll let you know if anything comes of that.

ABYC_LFP_Testing.pdf

[matty40s]

8 hours ago, MtB said:

 

 

None of which addresses the assertion being made about the ABC day boat conflagration, namely that the LFP batteries exploded.

The batteries didnt explode, the gas from overcharging exploded.

[MtB]

32 minutes ago, matty40s said:

The batteries didnt explode, the gas from overcharging exploded.

 

<sigh>

 

Yes WE know that. (Although on reflection we don't even know for sure the exploding gas originated from a battery - of any type.)

 

All the fuss however is because Mr Gnome says the LFP batteries themselves exploded.

 

And he is calling us here on CWF "wankers" for questioning his assertion the LFPs exploded.

 

What a charmer.

 

 

 

Edited September 20, 2025 by MtB
Add a bit.

[IanD]

23 minutes ago, matty40s said:

The batteries didnt explode, the gas from overcharging exploded.

Always assuming "the thing in the corner that went bang" *was* an LFP battery, which has not yet been established -- we do know that the two LFP rack batteries didn't explode, and probably weren't the cause of the problem.

 

Don't shoot the messenger -- what I was doing was presenting a letter on the subject of LFP safety, I deliberately didn't do this on the ABC boat thread... 😉

Edited September 20, 2025 by IanD

[Tonka]

1 hour ago, IanD said:

Always assuming "the thing in the corner that went bang" *was* an LFP battery, which has not yet been established -- we do know that the two LFP rack batteries didn't explode, and probably weren't the cause of the problem.

 

Don't shoot the messenger -- what I was doing was presenting a letter on the subject of LFP safety, I deliberately didn't do this on the ABC boat thread... 😉

You do know what probably means

[IanD]

12 hours ago, Tonka said:

You do know what probably means

Yes, which is why I said it. Your point is...?

Edited September 20, 2025 by IanD

[MtB]

1 hour ago, IanD said:

Yes, which is why I said it. Your point is...?

 

I was mystified by that question, too. 

 

 

 

[Tonka]

10 hours ago, IanD said:

Yes, which is why I said it. Your point is...?

That the batteries may have caused the fire.

Probably isn't as sure as the certainly didnt

[IanD]

1 hour ago, Tonka said:

That the batteries may have caused the fire.

Probably isn't as sure as the certainly didnt

You do know what "probably" means? 😉 

[1st ade]

19 minutes ago, IanD said:

You do know what "probably" means? 😉 

[Steve Bassplayer]

'Probably weren't' isn't the same as just 'probably' though. Maybe same as 'unlikely'? 

[NB Saturn]

1 hour ago, Steve Bassplayer said:

'Probably weren't' isn't the same as just 'probably' though. Maybe same as 'unlikely'? 

 

Probably not is more likely than “unlikely” usually, but theres a big spread in how individuals interpret it according to such thing as how credible they view the speaker, their emotional involvement in the topic etc. Studies have shown that some people will accord up to 50% probability for something described as unlikely when it’s an emotive or controversial subject, whereas others will attribute as low as 10%.

 

For this reason it’s best to avoid saying probably, probably not, likely, unlikely in any sort of scientific speaking/writing. Better to use such language as

 

“There’s less than a 10% chance this was the cause.” or  “We’ve ruled this out with high confidence”  which help anchor peoples mental models of the liklihood more accuratly.

[matty40s]

New idea.....just dont stand next to a Lithium battery boat on the towpath....

 

 

[1st ade]

4 hours ago, NB Saturn said:

 

Probably not is more likely than “unlikely” usually, but theres a big spread in how individuals interpret it according to such thing as how credible they view the speaker, their emotional involvement in the topic etc. Studies have shown that some people will accord up to 50% probability for something described as unlikely when it’s an emotive or controversial subject, whereas others will attribute as low as 10%.

 

For this reason it’s best to avoid saying probably, probably not, likely, unlikely in any sort of scientific speaking/writing. Better to use such language as

 

“There’s less than a 10% chance this was the cause.” or  “We’ve ruled this out with high confidence”  which help anchor peoples mental models of the liklihood more accuratly.

Which is why the MOD (and many other Agencies) use this...

 

"When we say it is 'highly unlikely' an explosion will take place, we feel it is less than 20% but more than 10% (and definitely more than zero!)"

[nicknorman]

15 hours ago, 1st ade said:

Which is why the MOD (and many other Agencies) use this...

 

"When we say it is 'highly unlikely' an explosion will take place, we feel it is less than 20% but more than 10% (and definitely more than zero!)"

It depends on the expected level of safety. In aircraft certification we use “extremely remote” for the failure of a critical thing, which is one in 10^9. If you were to say “there is a remote chance of this aircraft crashing and burning on landing” and that meant 5% ie one in 20 landings, I don’t think so many people would be swanning off to Benidorm for their summer hols.

Edited September 22, 2025 by nicknorman

[Mike Todd]

It is interesting that there was a lot of heated correspondence regarding the 'exploding' ABC day boat whilst the boat fire in a lock at the western end of K&A seems to have been hardly noted other than the inconvenience to others.

 

Since we seem not to know for sure what caused either, why the difference or is this discrimination  against the K&A (!) ?

[MtB]

4 hours ago, Mike Todd said:

It is interesting that there was a lot of heated correspondence regarding the 'exploding' ABC day boat whilst the boat fire in a lock at the western end of K&A seems to have been hardly noted other than the inconvenience to others.

 

Since we seem not to know for sure what caused either, why the difference or is this discrimination  against the K&A (!) ?

 

Thats easy. There is no bod asserting in YouTube videos that the batteries "blew up" causing the fire on the K&A fire. (Or is there?)

 

Its Mr Gnome's unsubstantiated and repeated assertions the batteries "exploded" rather than simply caught fire that had everyone questioning his statements. 

[1st ade]

23 hours ago, nicknorman said:

It depends on the expected level of safety.

Indeed - At our level it was "Highly Unlikely that country X will..." and had to be ready to defend "If you read it properly there is still a one-in-five chance that they will do whatever..."

[Steve Bassplayer]

1 hour ago, 1st ade said:

Indeed - At our level it was "Highly Unlikely that country X will..." and had to be ready to defend "If you read it properly there is still a one-in-five chance that they will do whatever..."

That defence example also shows how continous monitoring itself can reduce risk of things going badly wrong.

 

So for any system where lots of energy is stored, it's good to regularly check for signs that something isn't right.

 

Swelling of the battery packs could indicate a problem for example. Wire and connection insulation looking burnt or discoloured.

 

For gas installations, check the state of the joints and pigtails. Regular gas sniffer checks. 

 

Fuel installations, checks for fuel leaks....etc

 

 

 

 

Edited September 23, 2025 by Steve Bassplayer
Gumpy

[GUMPY]

21 minutes ago, Steve Bassplayer said:

That defence example also shows how continous monitoring itself can reduce risk of things going badly wrong.

 

So for any system where lots of energy is stored, it's good to regularly check for signs that something isn't right.

 

For LFP batteries, swelling of the battery packs could indicate a problem for example. Wire and connection insulation looking burnt or discoloured.

 

For gas installations, check the state of the joints and pigtails. Regular gas sniffer checks. 

 

Fuel installations, checks for fuel leaks....etc

 

 

 

 

The letters LFP are superfluous in the above quote.

[Tony Brooks]

4 minutes ago, GUMPY said:

The letters LFP are superfluous in the above quote.

 

Tempted to say, far more likely to find LA batteries swelling than LPF - sulphation.

[MtB]

3 minutes ago, Tony Brooks said:

 

Tempted to say, far more likely to find LA batteries swelling than LPF - sulphation.

 

 

And yet, when DIY constructing an LFP installation using prismatic bare cells I often read it is necessary to firmly clamp the four cells together in order to prevent them swelling. I've never understood why people do this as I'm not sure why they might swell in the first place. Or if they ever do. Or why it might matter if they did anyway!