LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[tanglewood]

Originally Posted by mat jam

I can see clearly that I have done what nobody should ever do - ask for some facts to support claims.

There are literally dozens and dozens of high quality research papers on all this. Google and read. I don't know why you are placing total credibility on what one guy says because he has a video camera and can post on youtube. A video camera doesn't make anyone any more credible than bubba down the dock.


And what's your point anyway? If you don't like LFP, or don't believe they perform as many have demonstrated, then don't buy any. If you want to see their performance proven out over more time, no problem. Wait as long as you want.


I just don't know why you are being so pissy about it.

[mat jam]

Originally Posted by tanglewood

There are literally dozens and dozens of high quality research papers on all this. Google and read. I don't know why you are placing total credibility on what one guy says because he has a video camera and can post on youtube. A video camera doesn't make anyone any more credible than bubba down the dock.


And what's your point anyway? If you don't like LFP, or don't believe they perform as many have demonstrated, then don't buy any. If you want to see their performance proven out over more time, no problem. Wait as long as you want.


I just don't know why you are being so pissy about it.

I was not the one being pissy as you say. I was not the one employing deceptive tactics to misrepresent credible info. I have read the scientific studies. They support what is in the video. Otherwise I would not have posted it. And why large players are sitting it out because as they say, the industry is in its infancy and there are many things that need to be worked out. Re-READ everything I have posted and show me where I have posted any inaccuracies. These batteries should stand on their own merits - they should not need people deploying deceptive tactics to misrepresent credible info. Anyone reading this topic has probably already figured out which posters are credible and which are not. And the reason people no longer trust comments and product reviews.

[evm1024]

Originally Posted by mat jam

I was not the one being pissy as you say. I was not the one employing deceptive tactics to misrepresent credible info. I have read the scientific studies. They support what is in the video. Otherwise I would not have posted it. And why large players are sitting it out because as they say, the industry is in its infancy and there are many things that need to be worked out. Re-READ everything I have posted and show me where I have posted any inaccuracies. These batteries should stand on their own merits - they should not need people deploying deceptive tactics to misrepresent credible info. Anyone reading this topic has probably already figured out which posters are credible and which are not. And the reason people no longer trust comments and product reviews.

The video has been presented 2 or 3 time in the thread and now including your post 3 or 4.

It is a good video and presents a lot of information on a number of Lithium chemistry's. If one is not careful one can miss when he references a different chemistry. And yes, they do have different names. The author shorthands them at times.

Lithium cobalt oxide, Lithium manganese oxide, Lithium iron phosphate, Lithium nickel manganese cobalt oxide, Lithium nickel cobalt aluminum oxide, Lithium titanate to name a few. The differences are not in the electrolytes. Sure you can use different electrolytes but they do not set the cell characteristics. And sure he does not name all of these in the video.

I can show you one inaccuracy:

Originally Posted by mat_jam

Your first reply appears to be an attempt at subterfuge. And now you are talking semantics. I concede the BMS does what it is supposed to do in varying degrees dependent on the supplier, but my summary IS that LifePO4 requires a lot of physical management in that if you want a long life cycle you should be careful how you use it which requires you doing a lot of managing in terms of the loads you put on it, how low you allow it to be discharged, etc.

Your above quote is totally inaccurate and a bit pissy. There was no subterfuge or deception. There is no need for the type of response you gave.

And how about:

Originally Posted by Mat_jam

There should be objective reasonable verifiable facts presented. I have yet to hear any argument against the main points presented in the video - one being - that if you take your batteries below 50% SoC you can expect hundreds NOT thousands of cycles.

Again you have posted in error. The video states that taking LiCoO2 below 50% can lead to lower cycle counts. The video specifically states that LiFePO4 can be cycled to low SOC without problems.

Really mat_jam you should take the time to read the entire thread. What is it, 8 years old, 6000 plus posts, 1,000,000 reads and you come here expecting to do what? Present new information based on a video that has been around for years and has been discussed in this thread and on CF half a dozen times?

I welcome any positive contribution you have to make.

[mat jam]

[QUOTE=evm1024;2856037]

The main contents of the video are about LifePO4.

He never said they could be not be taken down below 50%, he said there would be life cycle effects.

Have you read the scientific papers, latest one's from 2018?

Contribute how? In supporting a product that targets anyone not on the same game plan.

[Delfin]

Originally Posted by mat jam

Re-READ everything I have posted and show me where I have posted any inaccuracies.

Well, ok.

Originally Posted by mat jam

And pulse charging regimen is better than a constant current. With a properly engineered cell (all cells equally balanced) potentially charge 40-50% faster with a pulse technique.

This has been studied with Lithium Cobalt, and can be helpful, but as I noted initially, you seem to be confusing chemistries, since you won't find this advice for LFP. So, yes, this is inaccurate.

Originally Posted by mat jam

I have read elsewhere stated that with Lithium batteries you can expect 7 years if you do not go below 50% SoC without proper battery management and 10 years if you do not go below 50% SoC with proper battery management.

No one talks about years of service, they speak of cycles. It is true that if you draw an LFP battery to a higher SoC it will last longer than deeper discharges, but years are irrelevant. So this is also inaccurate.

Originally Posted by mat jam

Charge at 3.4 V

An LFP battery will spend most of its charge cycle at 3.4 volts during the CC phase. However, your comment suggests that this should be what the CV rate should be set at, and that is simply wrong. Inaccurate.

Originally Posted by mat jam

Do not let it go below 1.0 V.

LFP batteries will suffer damage long before a cell reaches 1.0 V, so this is dangerously inaccurate, since it is out of context.

Originally Posted by mat jam

Yet there are regular reports of users batteries just dying.

No, there are not. There are reports of users applying the same charge routine they do with LA batteries and killing them, but I've never heard of them "just dying". Inaccurate.

Originally Posted by mat jam

Re: Firefly - they say shipping cost and dangerous goods would require large quantities which would mean aging batteries in inventory.

Firefly are just AGM batteries and no more, nor less "dangerous" than other AGM batteries. Since you imply they are specifically dangerous, this is also inaccurate.

Originally Posted by mat jam

Otherwise they are just a novelty item with a large price tag that offer SOME benefits. And not cost effective over their use life cycle.

Simply math demonstrates that this is wildly inaccurate. Amortize the cost of LFP over 5,000 cycles vs. AGM over a few hundred.

Originally Posted by mat jam

MY LA batteries are nearing two years and there is no noticeable degradation. And they have been taken down below 50% numerous times in their first season and left with little charge in the off season until the next season.

You will not find any battery expert or manufacturer who will affirm your contention that storing an LA battery for months at partial charge without sulfation. Wildly inaccurate.

Originally Posted by mat jam

Just pointing out the weakness of an argument claiming a proof of longevity with 18 months experience.

Inaccurate. I merely pointed out my experience over 18 months and did not draw the conclusion from that experience that these batteries will last thousands of cycles. For that, I rely on published data, expert experience, much of which has been referenced in this thread.

Originally Posted by mat jam

With these batteries and what they promise, cruisers are using high current drawing appliances /equipment and drawing down their batteries to 20% which according to the expert will reduce life cycles considerably.

Your attempts at obfuscation is duly noted.

This was in response to a post from NewHaul who simply pointed out that the video you are relying on discusses high C discharge and charge rates and notes that this is not the typical boater usage. Wildly inaccurate.

Originally Posted by mat jam

If the data is so clear, why did you need to resort to subterfuge and obfuscation. What is becoming clear is that there are a number of posters with skin in the game trying to game the system.

Accusing people you disagree with as resorting to subterfuge and obfuscation, or that they are trying to game the system believing what they believe based on personal experience is scurrilous, never mind inaccurate.

Originally Posted by mat jam

One of the reasons users are choosing LifePO4 is in the belief they can take them down to 20% with no degradation. And they are adding high current gear that they normally would not have considered using which is putting additional stress on the batteries.

I know of no one who adds loads to their system because they install LFP. I have no idea where this idea comes from, but it is inaccurate.

Originally Posted by mat jam

All I ask is for some hard data or science.

This implies that you haven't been provided with hard data and science. Since you have, this is inaccurate.

Originally Posted by mat jam

I can see clearly that I have done what nobody should ever do - ask for some facts to support claims.

This thread is over 6,000 posts long. It is full of people asking questions, and full of people providing data in response. You are hardly "the first" as you suggest, so this is also inaccurate.

Originally Posted by mat jam

When you attempted to pull a fast one, I felt compelled to find the truth.

I merely pointed out that you were making fruit salad out of different chemistries in your statements, so no fast one, just an observation you took umbrage with. Inaccurate.

As EVM noted, if you have a positive contribution to make, I am sure all of us will welcome it. But you requested a list of inaccurate statements you have made, so perhaps the above will suffice.

[mat jam]

[QUOTE=Delfin;2856055]Well, ok.

I am quoting / paraphrasing the contents of the video. If there are any issues I suggest you take it up with Prof. Whitaker at CMU.

FYI batteries classification is - a dangerous good - ask the relevant authorities why.

This is ridiculous. Look what I have just written. Do you really expect me to take you guys seriously? I am done!

[nebster]

Originally Posted by mat jam

I am done!

I'll take the under.

[evm1024]

Originally Posted by mat jam

The main contents of the video are about LifePO4.

He never said they could be not be taken down below 50%, he said there would be life cycle effects.

Have you read the scientific papers, latest one's from 2018?

Contribute how? In supporting a product that targets anyone not on the same game plan.

Let's see what he said exactly. What time in the video did he say that discharge below 50% will reduce the cycle count from thousands to hundreds?

[Delfin]

Originally Posted by nebster

I'll take the under.

Safe bet.

[Delfin]

Originally Posted by mat jam

I am quoting / paraphrasing the contents of the video. If there are any issues I suggest you take it up with Prof. Whitaker at CMU.

I think if your paraphrase was accurate, or in context, no one would have an issue. The issue is that your paraphrase is inaccurate, out of context, and fails to understand what is actually being said by the good professor.

Originally Posted by mat jam

FYI batteries classification is - a dangerous good - ask the relevant authorities why.

So the "major retailer" you sought advice from doesn't carry batteries at all, I gather, since they are "dangerous goods". And you draw from this that they don't handle LFP because there is something special about them? Bit of a jump to conclusion to make for a professional researcher like yourself.

Originally Posted by mat jam

This is ridiculous. Look what I have just written. Do you really expect me to take you guys seriously? I am done!

I just quoted what you have written, and pointed out the statements you have made, per your request, where you are clearly confused. But surely out of the scores of posters who actually understand something about this topic there must be one who you can take seriously? If not, as someone else has posted, we can explain it to you, but we can't understand it for you.

I think one of the main sources of misunderstanding here is that you seem to feel that many on this thread care what batteries you use. I can't speak for others, but personally, I'm completely indifferent on the subject. Besides, you apparently have found magic LA batteries that don't sulfate when abused, so if that works for you, you are good to go.

[john61ct]

C'mon guys, he's promised to stop now.

Let's let it be maybe he'll honor that, no need to draw him back in.

And Delfin, I've never agreed with you more, great job there. . .

[paradox]

I need some collective help from the experienced Lithium house battery users here. I have an Oceanis 48 (beneteau) in new york on a mooring. I rarely get to a dock to charge. I have 300watts solar connected to my house bank via a victron charger.
my current set up is 660amps wet cell golf cart batteries (12v).
I have 2 40amp cristec battery chargers connected to a battery divider charging 3 banks (1. 100amp starting battery for engine 2. 100amp (24v) thruster battery 3. house bank)
My thruster batteries and starting batteries are in good shape. I would prefer to continue to use FLA/agm batteries as they exist. I want to change my house bank to Lithium (LiFePO4) since I have problems with voltage sag and not enough house bank to run my lights and refrig.
Can I reasonably use my current charging system and add Lithium house bank (500amp). Even at 80% DOD this will give me a larger house bank than I have now.
What is the risk to the lithium bank of using AGM battery chargers? If the whole house bank is shut down by the BMS, what is the risk of high alternator output to the electronics and exposure to higher than normal voltage (is this a real concern?) and do I need a Battery to Battery charger in line with the cristec charger before it reaches the lithium house bank?
appreciate your feedback

[CatNewBee]

So back to the discussion.

Today I browsed the media and read, that sever DHL electric delivery vehicle caught fire because of battery issues - especially because the welds inside the cell packs have had quality issues and caused overheating leading to 2 almost new vehicles catch fire.. They stopped 460 recently built vehicles and brought them off-duty until the issues were sorted. There are around 9000 of this type in the fleet.

It seems they use Li-Ion batteries made of smaller round-cells like Tesla.
But this can be a problem with drop-in LFP batteries built from small round cells too, because it is an mechanical / production process issue and not a result of the chosen chemistry.

For those who are curious how they look like: Street-Scooter based on Ford chassis

[sparrowhawk1]

Paradox, as someone who has lived on the hook for over 30 years and has tried many different ratios as far as solar panel wattage to amp hour capacity battery with LA, my opinion is you need at least the same wattage in solar panels as amp hours, in other words 600 watts for a 600 amp hour battery pack, better to have 800 watts.

[Delfin]

Originally Posted by paradox

I need some collective help from the experienced Lithium house battery users here. I have an Oceanis 48 (beneteau) in new york on a mooring. I rarely get to a dock to charge. I have 300watts solar connected to my house bank via a victron charger.
my current set up is 660amps wet cell golf cart batteries (12v).
I have 2 40amp cristec battery chargers connected to a battery divider charging 3 banks (1. 100amp starting battery for engine 2. 100amp (24v) thruster battery 3. house bank)
My thruster batteries and starting batteries are in good shape. I would prefer to continue to use FLA/agm batteries as they exist. I want to change my house bank to Lithium (LiFePO4) since I have problems with voltage sag and not enough house bank to run my lights and refrig.
Can I reasonably use my current charging system and add Lithium house bank (500amp). Even at 80% DOD this will give me a larger house bank than I have now.
What is the risk to the lithium bank of using AGM battery chargers? If the whole house bank is shut down by the BMS, what is the risk of high alternator output to the electronics and exposure to higher than normal voltage (is this a real concern?) and do I need a Battery to Battery charger in line with the cristec charger before it reaches the lithium house bank?
appreciate your feedback

I have a similar setup to yours - combining LFP with another chemistry - and I make it work. I do so by manually terminating charging the LFP when they are full, as measured by the acceptance rate dropping to < 5% of capacity. I do this through a Blue Seas automatic charging relay that directs charging capacity after the LFP bank is full to the starter battery. I have no solar, so when I am charging I am underway (we're a stinkpot), or I am running the genset.

Mine is a 24 vdc system, and I have the everyday charge voltage in bulk set to 28.2, which is also fine for the LA starter. Absorption is set to around 20 minutes, but as I said, I disconnect the LFP from charging when current acceptance drops, and that usually happens before the absorption period would expire. Float is where it gets tricky. In my system, I don't float, I disconnect. Some with LFP float, but at a low enough voltage that the battery is essentially not being charged, but that is not going to be optimum for the LA bank.

It seems to me that if your solar supplies only a fraction of your actual draw during the day, you could let it flow into the LFP without any issue. Or, disconnect the LFP from solar (while keeping it to power house loads) and direct that current to your starter/thruster bank with a float setting appropriate for them.

Hope that helps....