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Old 17-09-2023, 10:49   #31
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Re: LifePO4 chemistry not as important as we thought

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Originally Posted by FlyingScot View Post
I have, for example, a number of photos of burned up LiFePO4 batteries, and knowledge of disastrous boat fires from LiFePO4 batteries. On the other side of the ledger, there are likely now hundreds of thousands of Torqeedo batteries in marine use (I have six on my boat which have all seen hard service over a number of years), all of which use the NMC chemistry, with no significant history of thermal runaway.

Nigel
So two comments on this.

First, his comments on LFP are quite scary and completely opposite the commonly held wisdom. He has numerous photos of burned up batteries and knowledge of disastrous boat fires (note the plural) from LFP batteries. If he is correct, this leads to serious reevaluation of LFP on a boat. But frankly, I don't think he is correct. Is anyone aware of fires that started as a result of LFP (fires on connected devices don't really count, as I can burn up a wire or a device or an alternator with an AGM battery just as easily.) Does anyone even have photos of burned up lfp batteries resulting from in-service use? (Again, experiments don't count).

I also question his assertion that there are hundreds of thousands of torquedo batteries out there. I'm not sure I would even believe tens of thousands. Overstatement for effect in my mind dilutes the effect.
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Old 17-09-2023, 11:25   #32
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Re: LifePO4 chemistry not as important as we thought

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So two comments on this.

First, his comments on LFP are quite scary and completely opposite the commonly held wisdom. He has numerous photos of burned up batteries and knowledge of disastrous boat fires (note the plural) from LFP batteries. If he is correct, this leads to serious reevaluation of LFP on a boat. But frankly, I don't think he is correct. Is anyone aware of fires that started as a result of LFP (fires on connected devices don't really count, as I can burn up a wire or a device or an alternator with an AGM battery just as easily.) Does anyone even have photos of burned up lfp batteries resulting from in-service use? (Again, experiments don't count).

I also question his assertion that there are hundreds of thousands of torquedo batteries out there. I'm not sure I would even believe tens of thousands. Overstatement for effect in my mind dilutes the effect.
Torqeedo says on their website:

https://www.torqeedo.com/us/en-us/ne...was%20launched.

Overall, Torqeedo has now sold over 200,000 electric motors and firmly established the market for eco-friendly electric mobility on the water. On Lake Starnberg, Torqeedoís birthplace, the number of people using electric boats has more than quintupled since the original Travel motor was launched.
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Old 17-09-2023, 13:51   #33
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Re: LifePO4 chemistry not as important as we thought

I think the BMS ďqualityĒ is interdependent with the battery chemistry.

With todayís chemistries, I think LFP stands apart because it is so much less dangerous if something does go wrong and the BMS fails too.

With other chemistries, I think a greater level of rigor is required in the BMS because itís a sure disaster if something goes wrong and it is not caught by the BMS
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Old 17-09-2023, 14:19   #34
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Re: LifePO4 chemistry not as important as we thought

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With todayís chemistries, I think LFP stands apart because it is so much less dangerous if something does go wrong and the BMS fails too.
What would that "go wrong" be?

Pretty sure I have read ABYC tried everything.
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Old 17-09-2023, 15:28   #35
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Re: LifePO4 chemistry not as important as we thought

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Originally Posted by FlyingScot View Post
Torqeedo says on their website:



https://www.torqeedo.com/us/en-us/ne...was%20launched.



Overall, Torqeedo has now sold over 200,000 electric motors and firmly established the market for eco-friendly electric mobility on the water. On Lake Starnberg, Torqeedoís birthplace, the number of people using electric boats has more than quintupled since the original Travel motor was launched.
I stand corrected. It is an astounding number! I've certainly seen a few, but not enough for me to have thought there were 200,000! It's true that it's an international market and so my US-centric thought is a fallacy right there.
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Old 17-09-2023, 15:30   #36
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Re: LifePO4 chemistry not as important as we thought

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What would that "go wrong" be?



Pretty sure I have read ABYC tried everything.
I think he's referring to what could go wrong in the ancillary systems. The charger on wholesale runaway, and no disconnect from the BMS. His point was that even if it goes completely sideways, there shouldn't be a problem.

But ABYC and our understanding disagrees with Nigel's comment that he has seen several fires and burned up batteries.
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Old 17-09-2023, 19:28   #37
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Re: LifePO4 chemistry not as important as we thought

LFP batteries burn almost as good as a 2x4, which is less than most other materials of your boat.

So if you have a fire and throw some LFP batteries in, then youíre gonna see burned LFP batteries, but no fires were started because of LFP batteries. In every case I have seen presented, it was clearly cabling that caused the fire.

So the suggestion that LFP is as dangerous as other chemistries is simply wrong. When done so as to whitewash the dangers of other chemistries, itís downright evil.
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Old 18-09-2023, 10:54   #38
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Re: LifePO4 chemistry not as important as we thought

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What would that "go wrong" be?



Pretty sure I have read ABYC tried everything.


I guess I have a couple of responses

First is that this is exactly what I mean. Something going horribly wrong with LFP, like uncontrolled overcharging, is a limited threat. As a result, I donít think itís as important that a BMS be redundant, failsafe, tested and certified by everyone in the world, etc. In contrast, a failed BMS that allows uncontrolled overcharge of an NMC bank could pose a significant threat. In that case, I think having more rigid standards for such a BMS makes sense, because the consequences of failure are so much higher. This is what I was trying to say in my previous post, but perhaps with too much economy with words Ö.

As for the ABYC testing, I would give it no more credibility than the many YouTube videos of people bashing on LFP batteries. Why? Because ABYC has not published any information about what they actually did. I donít see how anyone can assign any credibility to testing when you donít know what they actually did. Itís just more anecdotal blah blah blah. As an ABYC member, member of the Electrical Project Technical Committee, and member of the Lithium Battery sub committee, I have no idea what testing was done, who did it, what batteries were tested, nor how they were tested. Iím embarrassed for ABYC, and personally embarrassed by this.
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Old 18-09-2023, 14:11   #39
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Re: LifePO4 chemistry not as important as we thought

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As for the ABYC testing, I would give it no more credibility than the many YouTube videos of people bashing on LFP batteries. Why? Because ABYC has not published any information about what they actually did. I donít see how anyone can assign any credibility to testing when you donít know what they actually did. Itís just more anecdotal blah blah blah. As an ABYC member, member of the Electrical Project Technical Committee, and member of the Lithium Battery sub committee, I have no idea what testing was done, who did it, what batteries were tested, nor how they were tested. Iím embarrassed for ABYC, and personally embarrassed by this.
Thatís why UL 1973 certification is important.
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Old 18-09-2023, 15:29   #40
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Re: LifePO4 chemistry not as important as we thought

Yes. I think Jedi has it right. If we go way back to the OP's question of "Chemistry or Quality":

1- "Chemistry" for lithium house banks on boats is always LFP. No other lithium chemistry is appropriate. Nigel confuses things by conflating the safety issues of other chemistries that are never used on cruising boat lithium battery banks.

2- Quality - As with everything on a boat, quality matters. In the case of LFP batteries for a house or start bank, they should at a minimium be UL1973 certified. They are then as safe or safer than AGM or flooded batteries.

Of course a safe installation includes other issues such as wire gauge, fusing, securing batteries - but "installation" is not directly part of either battery chemistry or quality.
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Old 18-09-2023, 16:21   #41
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Re: LifePO4 chemistry not as important as we thought

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Thatís why UL 1973 certification is important.


Do you guys know whatís in 1973? Itís for power systems in light rail applications and large stand alone power systems. I can see it for a propulsion power system using NMC batteries to power a passenger ferry. But a recreation boatís house bank using LFP? I think itís crazy overkill.
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Old 18-09-2023, 16:24   #42
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Re: LifePO4 chemistry not as important as we thought

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Do you guys know whatís in 1973? Itís for power systems in light rail applications and large stand alone power systems. I can see it for a propulsion power system using NMC batteries to power a passenger ferry. But a recreation boatís house bank using LFP? I think itís crazy overkill.

Oh no, overkill on an important system!
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Old 18-09-2023, 17:02   #43
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Re: LifePO4 chemistry not as important as we thought

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From the comments of the last video I posted:


... I have, for example, a number of photos of burned up LiFePO4 batteries, and knowledge of disastrous boat fires from LiFePO4 batteries. On the other side of the ledger, there are likely now hundreds of thousands of Torqeedo batteries in marine use (I have six on my boat which have all seen hard service over a number of years), all of which use the NMC chemistry, with no significant history of thermal runaway. Itís all in the engineeringÖ Note that this is not an endorsement of Torqeedo Ė I do not do endorsements Ė but simply a recognition of their history with li-ion batteries.



Nigel
Is anyone going to call out Nigel on this? Where are these photos and disastrous boat fires caused by LiFePO4? Because with a whole lot of searching, many other reputable professionals haven't found them. AFAIK, they are all hearsay.

What I personally have seen, in RV's, are electrical fires that started adjacent to the LiFePO4 battery, spread to them, and then went out on its own once the most flammable stuff (wood etc.) burned and/or oxegen in the compartment was used up. The batteries were a melted mess, but never went into runaway. And the RV was salvageable, mostly with smoke damage throughout, and lots of electrical work. I have seen photos of several RVs that had this happen.

I welcome evidence of more than that, on a boat, RV, or anywhere, with LiFePO4.

There absolutely are documented cases of battery issues with Torqueedo. At least one recall, and numerous warnings about battery fires. IIRC there was a user on this forum a while back that had a Torqueedo battery smoking and going into runaway after having been dropped in the water. These are fires that would not happen if they used LiFePO4.

I am not hard-nosed that NMC shouldn't ever be used on a boat. NMC has a higher energy density. When used for propulsion, it very well may be worth the extra engineering to make them safe, and for that they should be allowed. Not very many boat owners are doing that. It needs to be recognized that much higher levels of protection are needed with NMC. And that with no special effort at all LFP is at least as safe as the Lead Acid they replace. A BMS on LFP saves the battery from damage, it isn't needed to prevent fires.
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Old 18-09-2023, 17:08   #44
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Re: LifePO4 chemistry not as important as we thought

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Is anyone going to call out Nigel on this? Where are these photos and disastrous boat fires caused by LiFePO4? Because with a whole lot of searching, many other reputable professionals haven't found them. AFAIK, they are all hearsay.
I wouldn't consider Nigel an independent tester
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Old 19-09-2023, 01:05   #45
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Re: LifePO4 chemistry not as important as we thought

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”... LiFePO or LFP (lithium iron phosphate) and LiNMC (lithium nickel manganese cobalt) are both types of lithium-ion batteries. LFP and LiNMC batteries have unique sets of benefits and drawbacks. At Torqeedo, we use both chemistries for different boating applications...”
More ➥ https://www.torqeedo.com/us/en-us/te...echnology.html
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