Graham376
Well-Known Member
Whatever the truth, it's likely more ammunition for insurance underwriters wishing to make life more difficult.
Self install of LifePo4 and what requirements for insurance (UK)
- Thread starter davethedog
- Start date
billskip
Well-Known Member
Well i don't know if what caused the fire, but there is for sure a reason and until that reason is known you are wise to keep your opinions of others to yourself.
billskip
Well-Known Member
More money.
As insurance becomes more compulsory the happier the are, and they know how to take your money and know there's absolutely no chance of them paying out on some policies.
lustyd
Well-Known Member
By the same token people should avoid speculating wildly and suggesting that lithium is dangerous based on nothing at all. Otherwise they invite criticism as has been seen from the majority on the other thread.
Graham376
Well-Known Member
Here's the viewpoint from a guy present in the marina when the fire happened. He was already against EVs but I haven't seen the earlier video to which he refers.
Tranona
Well-Known Member
Suggest you look at the new video on the thread on Scuttlebutt which does seem to add a bit more information about the boat. Pluss of course some new guesswork and misinformation
Always a problem when 2 threads running on similar subjects
Tranona
Well-Known Member
Graham
Done to death (almost) here forums.ybw.com/threads/a-man-who-does-not-mince-his-words.621434/page-7#post-8662969
lustyd
Well-Known Member
I was removed from the other thread for saying uncomplimentary things about a conspiracy theorist.
Does the new video contain facts or more speculation? I’m not supporting such Youtubers by adding to their views. If there’s information then there ought to be sources to verify.
Graham376
Well-Known Member
Tranona
Well-Known Member
A bit more "fact" in that the US dude shows some photos of the installation of batteries, motor and controls of a similar boat in the same fleet. It is a Beta installation with Victron chargers and 2 * 20 kWh banks, one for propulsion and one for domestic which he claims are located under the aft deck. Suggests that the fumes from overcharging might have leaked into the forward area through gaps around the cable runs in the bulkhead and maybe set off by sparks from the fridge starting up. Only reporting what he says. Does not make total sense as the aft part of the boat where he claims the batteries are seems totally unscathed.
lustyd
Well-Known Member
This in itself would be enough to disprove the “lithium fire” theory. If the lithium were burning in the way being suggested the area the lithium is stored would be totally destroyed as Lithium Ion fires as seen in cars are self sustaining and extremely hot.
If the batteries weren’t themselves on fire then that suggests a standard electrical fire or galley fire, both far more likely.
Was there any evidence of what chemistry the batteries were?
Tranona
Well-Known Member
He just refers to them as LFP. The photos from the similar bot show a 48v bank of "Predaroe2 brand batteries. He is a loud US youtuber fire "expert" working from the video and photos of a similar installation which also included the cabin showing the electric appliances including the fridge. This is the area of the explosion.
Really no evidence of the cause unsurprising as he is 4000 miles away
Really no evidence of the cause unsurprising as he is 4000 miles away
aqua_sax
Well-Known Member
The American guy with the General Custer moustaches does bang on rather, but the batteries from another similar boat that he shows in his video are Predator XBT batteries and they are LifePO4 batteries. Screen grab from the video:
Description from a website that sold these batteries:
But the video from another boat doesn't prove these were the batteries on the boat that did explode.
His theory about what caused they explosion is that the batteries produced a LOT of hydrogen (to much to be explosive in the battery space as not enough air?) which then entered the main saloon area where it mixed with air to form a highly explosive mixture that was ignited, maybe by a spark from the fridge. This could explain why the explosion happened where it did, and why the battery area itself appears unaffected.
Does anyone know whether LiFePO4 batteries can produce significant amounts of hydrogen? If they can, then that may be important...
Description from a website that sold these batteries:
But the video from another boat doesn't prove these were the batteries on the boat that did explode.
His theory about what caused they explosion is that the batteries produced a LOT of hydrogen (to much to be explosive in the battery space as not enough air?) which then entered the main saloon area where it mixed with air to form a highly explosive mixture that was ignited, maybe by a spark from the fridge. This could explain why the explosion happened where it did, and why the battery area itself appears unaffected.
Does anyone know whether LiFePO4 batteries can produce significant amounts of hydrogen? If they can, then that may be important...
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aqua_sax
Well-Known Member
I've now found the paper where General Custer got his gas production during thermal runaway diagram.
From the abstract from the same paper:
"The primary gas components during thermal runaway for both NCM and LFP batteries include H2,CO,CO2,C2H4, and CH4. The gas produced by LFP batteries contains a high proportion of H2. The high concentration of H2 results in a lower flammability limit (LFL) for the gas generated by LFP batteries during TR compared to the mixed gas produced by NCM batteries. Therefore, in terms of battery TR gas composition, the order of hazard level is LFP > NCM811 > NCM622 > NCM523 > NCM9 0.5 0.5 0.5. Although experimental results show that LFP batteries have superior thermal stability and lower gas production during large-scale battery thermal runaway events, considering gas generation composition and thermal runaway products, the thermal runaway risk of LFP batteries may be higher than that of NCM batteries."
I shouldn't need to point out these findings are 'in vitro' findings, and the conclusions are tentative ("thermal runaway risk of LFP batteries may be higher", [emphasis added]), but they may provide food for thought.
From the abstract from the same paper:
"The primary gas components during thermal runaway for both NCM and LFP batteries include H2,CO,CO2,C2H4, and CH4. The gas produced by LFP batteries contains a high proportion of H2. The high concentration of H2 results in a lower flammability limit (LFL) for the gas generated by LFP batteries during TR compared to the mixed gas produced by NCM batteries. Therefore, in terms of battery TR gas composition, the order of hazard level is LFP > NCM811 > NCM622 > NCM523 > NCM9 0.5 0.5 0.5. Although experimental results show that LFP batteries have superior thermal stability and lower gas production during large-scale battery thermal runaway events, considering gas generation composition and thermal runaway products, the thermal runaway risk of LFP batteries may be higher than that of NCM batteries."
I shouldn't need to point out these findings are 'in vitro' findings, and the conclusions are tentative ("thermal runaway risk of LFP batteries may be higher", [emphasis added]), but they may provide food for thought.
Sea Change
Well-Known Member
Very interesting. I didn't see any mention of how much gas was given off by each type of battery, just the comparison of the proportions. I suppose you'd have to measure it by Ah of battery to give a fair and useful result.
aqua_sax
Well-Known Member
I agree, using a percentage chart is potentially misleading for total volumes. It needs a very careful reading of the paper which am doing right now. So far it seems likely the LiFePO4 battery gave off far less gas, and at a different time, based on the pressure rise during the experiment (Figure 6(b):
Immediately before Figure 6 the authors observe "On the other hand, the LFP battery does not exhibit TR phenomenon, but due to excessive internal pressure, the vent valve opens to release gas."
lustyd
Well-Known Member
Even if we assume that’s the case (and I highly doubt it) it still isn’t a “lithium battery fire”.
Seems at least as likely to me that the “explosion” was a standard backdraft that any fire produces when air is added and the fire was an electrical or galley fire. Hydrogen is a pretty specific kind of explosion and if that was the start then flames wouldn’t have been present until later if at all.
I feel like a lot of folk are reaching for reasons it was battery related when occam’s razor would suggest numerous more likely events. Even the evidence being put forwards suggests it’s not a battery fire so seems odd so many are determined it was.
aqua_sax
Well-Known Member
And here is a table from the paper showing, conveniently, gas production per Ah:
It's late on a sunny Sunday evening hereabouts and I am going to call it a day, a sundowner beckons, but at 0.569L/Ah, an 100A/h LiFePO4 battery might suddenly produce over 50L of gas, of which more than 50% is hydrogen....
It's late on a sunny Sunday evening hereabouts and I am going to call it a day, a sundowner beckons, but at 0.569L/Ah, an 100A/h LiFePO4 battery might suddenly produce over 50L of gas, of which more than 50% is hydrogen....
lustyd
Well-Known Member
Is that worse than Lead Acid?
lustyd
Well-Known Member
A quick Google suggests thats not only better than Lead Acid, but that it only happens during extremely rare thermal runaway. Lead batteries off gas any time the current is above acceptance rate and they generate very significant quantities in comparison.
Thermal runaway won’t happen on an LFP properly installed with modern chargers correctly configured.
