Can you de-bloat XUBA 280aH Lifepo4 cell?

[sremick]

It is perfectly normal behaviour!!!
The cells are not damaged.
Yes, it looks funny / strange / concerning.
Capacity wise, life cycle still the same.

I don't feel I can agree with this. I've done a lot of research myself. The vents are a safety measure so that if damage is causing gasses to build up, they are released in a controlled manner with plenty of dilution with air vs. building up pressure and causing an explosion (physical and/or fire).

The gasses result from the breakdown of the electrolyte (physical, thermal or electrical stress out of scope) and are flammable. If any venting has occurred, there is damage to the battery.

Sources:
Lithium Battery Thermal Runaway Vent Gas Analysis
November 2016
U.S. Department of Transportation, Federal Aviation Administration

Lithium-Ion Battery Hazard and Use Assessment
2011
Mikolajczak, Kahn, White, Long

Modeling Lithium Ion Battery Safety: Venting of Pouch Cells
July 2013
Santhanagopalan, Yang
National Renewable Energy Laboratory, USDOE

 

[Frank in Thailand]

I don't feel I can agree with this. I've done a lot of research myself. The vents are a safety measure so that if damage is causing gasses to build up, they are released in a controlled manner with plenty of dilution with air vs. building up pressure and causing an explosion (physical and/or fire).

The gasses result from the breakdown of the electrolyte (physical, thermal or electrical stress out of scope) and are flammable. If any venting has occurred, there is damage to the battery.

Sources:
Lithium Battery Thermal Runaway Vent Gas Analysis
November 2016
U.S. Department of Transportation, Federal Aviation Administration

Lithium-Ion Battery Hazard and Use Assessment
2011
Mikolajczak, Kahn, White, Long

Modeling Lithium Ion Battery Safety: Venting of Pouch Cells
July 2013
Santhanagopalan, Yang
National Renewable Energy Laboratory, USDOE

Yes, you are correct about lithium ion, and concerning lithium ion, I totally agree.

If you done like me research, you also would have researched the production process.
During this process gassing is normal behaviour for the first (couple of) charge cycles.
Most of it occurs during initial (70%) charge at the production process.
There is always better, and our cheap pricing does have some downside, production process is probably less neat as from "real grade A" cells.
That doesn't mean these are bad.
Not at all.

Again:
Lifepo4 is not the same as Lithium Ion !!
Yes, they both contain lithium, and the process is more or less the same.

Apple and pear both grow at a tree, and are fruit, yet, totally different.

The gassing from lifepo4 is not flammable.
The gassing from lithium ion is.

Can I agree that there is some degree of damage?
Yes, sure.
Every time you cycle there is damage, micro cracks or how you want to call it.

Excessive gassing, while normal behaviour during production, will give some degree of damage.
Like a few charge cycles do.
Nothing significant.

Please STOP comparing Lifepo4 with lithium Ion!!!
They are not the same!
Lithium ion can be dangerous.
Explosive, fire.
Lifepo4 is NOT!!

I did a quick search for you YouTube to show the difference between lithium battery types

The video tells more then 10.000 words.

If you are not convinced, luckily there are dozens of examples.

I know it is not what you like to hear.
It's more easy to blaim the seller or producer then ourselves.

The light aluminium housing batteries are not intended to be used as-is.

They are intended to be compressed to eachother, allowing the pressure inside the cell to rise.
As result, there is no gassing.
No gassing, no bloating.
For a solid or liquid to change to gas, there are several factors that play a role.

Pressure is a huge one.
Low pressure, water gasses at 70 degree high pressure, it starts at 130 degree Celsius.
That is just how nature works, nothing special for batteries.

The tons of cells with bloating that are standing free, and the tons of cells that aren't bloating that are compressed should be enough proof.

Both the same type of cells, thin aluminium housing.
Both being normally used, yet one of the 2 is bloating..
What's the difference between them?

You should take my word for it.
Do your own research.
Proof me wrong..

Bloated Lithium ion and lifepo4 cells are nasty to look at.
Lucky there are many capacity tests between them on internet.

Producers claim already since the start of lithium battery that it does not effect lifecycle or capacity.

I'm still waiting to see research that shows them wrong.
* I talk about slight bloating, like my cell.
As said, there will be minor damage and some (minimal) capacity loss.
No effect, that's not correct.
Some.
Not enough to stop using your cell with the rest of the array.
It will work just fine.

Feel free to let fear guide you.

I'm happy to receive the cells you are afraid to use!!

Even willing to pay the postage costs.
They have many years of useful life in them, and I can always use some expansion of my 736Ah

Fear with lithium Ion.
Yes.
You should be afraid.
YouTube (again ? ) is full of videos where mobile phones spontaneous combust. Or E-bike.
Lithium ion is not safe.

 

[Luthj]

Proof me wrong..

You misunderstand the burden of proof. You are asserting that bloated, over volted cells, is "normal". Though you contradict yourself in several places. Thus you have the burden of proof. It is not our responsibility to demonstrate your assertion!


FYI, Lithium polymer batteries are the most flammable type because they use a polymer electrolyte which will always burn when the casing is punctured.

I repeat LFP electrolyte is flammable and toxic. Typical venting conditions do not ignite the electrolyte. But in a closed space, a spark can cause an explosion if electrolyte is present. It is rare, but should not be discounted.

If the cell has vented in any significant way, it should be discarded. Read the spec sheets or contact the vendor, they will say exactly the same thing. In the case of some cells, they do not have a valve, but a burst disk. If the disk bursts the cell will slowly dry out and fail.

Lithium ion is not safe.

This is the last time I will say this. For the good of newbs who are reading. LFP IS lithium ion. So is LiPo, so is LCO, so is NMC. They all work by moving lithium ions from the cathode to the anode and back. The fact that you don't understand this indicates that you are an amateur.

Your suggestions are both dangerous and lacking in a basic understanding of the chemistry involved.

Wikipedia specifically discusses LFP, and its lower (but not zero) flammability risk.

Lithium-ion battery - Wikipedia

en.wikipedia.org

 

[Frank in Thailand]

The bloating on my 152Ah cell.

I let fear guide me, and bought replacement.
After extensive testing and longer time use in my 48+16 cell array (48*152) I can only say that there is no noticeable difference between the not bloated cells

For cycle life.
I can not tell you
I simply don't have the equipment to do that kind of tests.
Probably in 10 years I can tell.

 

[Luthj]

You need to assess why the cells are swelling to that extent.

Do you have a working BMS?
What charge voltage are they seeing?

These are simple questions which will typically account for 90% of issues with cell damage.

 

[sremick]

If you done like me research

I did,. And provided links to the accredited scientific research papers.

Lifepo4 is not the same as Lithium Ion !!

Actually, technically LiFePO4 IS a type of lithium ion battery (look it up). I will concede that colloquially what consumers typically refer to as "lithium ion" are categories of lithium-ion batteries OTHER than LiFePO4 lithium-ion batteries, but it's important to understand that scientifically, LiFePO4 IS a "lithium ion" battery and as we refer to scientific research, scientists care about technical definitions over colloquial ones.

And the research I linked to explicitly mentions LiFePO4, so there's no ambiguity anyway.

The gassing from lifepo4 is not flammable.

Sorry, but this is demonstrably and scientifically proven to be false. It's outlined in extensive scientific detail with charts and data in one of those papers I linked to. They specifically studied LiFePO4 batteries as well as other lithium-ion chemistry batteries.

That one is simple enough that it becomes hard to give the rest of your claims much credibility (as empassioned as they may be).

Do your own research.
Proof me wrong..

I did.

 

[Frank in Thailand]

You misunderstand the burden of proof. You are asserting that bloated, over volted cells, is "normal". Though you contradict yourself in several places. Thus you have the burden of proof. It is not our responsibility to demonstrate your assertion!


FYI, Lithium polymer batteries are the most flammable type because they use a polymer electrolyte which will always burn when the casing is punctured.

I repeat LFP electrolyte is flammable and toxic. Typical venting conditions do not ignite the electrolyte. But in a closed space, a spark can cause an explosion if electrolyte is present. It is rare, but should not be discounted.

If the cell has vented in any significant way, it should be discarded. Read the spec sheets or contact the vendor, they will say exactly the same thing. In the case of some cells, they do not have a valve, but a burst disk. If the disk bursts the cell will slowly dry out and fail.






This is the last time I will say this. For the good of newbs who are reading. LFP IS lithium ion. SO is LiPo, so is LCO, so is NMC. They all work by moving lithium ions from the cathode to the anode and back. The fact that you don't understand this indicates that you are a youtube cowboy. Yes there is good info there, but it is not the same as actually understanding the chemistry.

Your suggestions are both dangerous and lacking in a basic understanding of the chemistry involved.

I guess you are lacking the basic understanding between the different types of lithium batteries.

Lifepo4 and and lithium ion, both indeed use ions.
Yet, they are as different as Apple and Pear are.

To keep this comparison, Apple being lithium ion and pear lifepo4....

Apple's are dangerous goods.
Pears are not.

No matter how the pear look, it doesn't become as dangerous as an apple.

You can try to convince people it will be, and some might believe you.
Extra safety doesn't hurt, except their wallet.
It's totally unnecessary!!

We are talking about bloating, not bursting of vents.
I'm sure that in the right conditions you can ignite the gass escaping from lifepo4.

Those conditions normally aren't occuring.
The explosive gasses from lithium Ion, they do.

For the newbies:
To make it simple
lithium ion battery is 3.7 volt,
lifepo4 is 3.2 volt

If your fully charged cell (after a few hours rest) is about 3.7 volt, it is the explosive type.
If your fully charged cell is about 3.3 volt, it's the safe type.

Feel free to let fear guide you.
The world is flat and you will fall off.
There are still loads of people who know this to be true.

And loads that know better.

I am serious about my offer.
If you are afraid to use them, please do send them to me, I pay for the postage costs.

As they're lifepo4 (and not lithium Ion) you can send them via normal regular mail.

Lithium ion are dangerous goods and need to be carefully transported.

Take from it what you need, use your own mind and do your own research.
Don't be a parrot that just shouts how dangerous it is, when it obvious is not.

If the video isn't enough proof, nothing will be.
Then please PM me for my address

☮

 

[BiduleOhm]

@Luthj @sremick I recommend you stop trying arguing with @fhorst (unless you have time of course) because I tried the same thing a few months ago (to convince him about how cells swell a bit, like 1 mm, when fully charged and how that could lead to metal fatigue and failure if you use rigid busbars; but they didn't and metal fatigue isn't happening according to him) and after dozens of posts I stopped trying because he wouldn't even try to listen and understand what I explained, and it wasn't worth my time.

 

[Luthj]

@Luthj @sremick I recommend you stop trying arguing with @fhorst (unless you have time of course) because I tried the same thing a few months ago (to convince him about how cells swell a bit, like 1 mm, when fully charged and how that could lead to metal fatigue and failure if you use rigid busbars; but they didn't and metal fatigue isn't happening according to him) and after dozens of posts I stopped trying because he wouldn't even try to listen and understand what I explained, and it wasn't worth my time.

Yeah, I am not trying to change his mind. But I don't want some newb blowing up his shed (or house!), so I try to point out dumb/wrong advice.

I had a friend nuke a 20kw CALB? pack years ago when some solid copper bus bars caused the cell casing/terminal to crack due to high cycle fatigue. It took 5 years or so, but the damage was pretty spectacular... Had a friend nearly kill himself working alone on an EV because 90VDC is "low voltage". Fools will as fools do.

If I had some low criticality application away from humans, where the cost of failure was minimal. Sure, I might use bloated cells. Running some remote lighting, electric gates, maybe a water pumping station in a field somewhere. But in an RV? Home? Garage? Sorry, seen enough electrical fires...

 

[Luthj]

Hi Luthj
Can I ask ......... where you sourced your 12X280AH batteries?
...

I think you have me confused with the OP. While coincidentally, I do have some EVE cells somewhere in the pacific, I don't have any on my bench.

 

[sremick]

I can not tell you
I simply don't have the equipment to do that kind of tests.

The actual scientists with research experience and who do "have the equipment to do that kind of tests" have done the tests and the data and their conclusions contradicts just about everything you're claiming.

You are incorrect about the purpose about the vents.
You are incorrect about the cause of gassing and whether it is the result of electrolyte damage.
And you are incontrovertibly incorrect about your ridiculous claim that the gasses vented by a LiFePO4 are not flammable.

On top of all that, what you are encouraging others to do is dangerous and irresponsible. All your cute analogies and metaphors are not science.

Are Lithium-cobalt-oxide (LCO) batteries more dangerous than LFP batteries? Certainly
Is it easier for an LCO battery to have thermal runaway and outgas compared to an LFP battery? Yes.
However, if an LFP battery does vent gasses those gasses contain hydrogen and assorted flammable hydocarbons. Such as: methane, ethylene, acetylene, propene, propane, ethane, butene, and butane.

I guess you are lacking the basic understanding between the different types of lithium batteries.

I don't think that's the actual problem here...

@Luthj @sremick I recommend you stop trying arguing with @fhorst (unless you have time of course) because I tried the same thing a few months ago (to convince him about how cells swell a bit, like 1 mm, when fully charged and how that could lead to metal fatigue and failure if you use rigid busbars; but they didn't and metal fatigue isn't happening according to him) and after dozens of posts I stopped trying because he wouldn't even try to listen and understand what I explained, and it wasn't worth my time.

Yeah I'm done here. I just to hope to high heaven that no newbie hurts themselves (or worse) by following his insane advise.

 

[BiduleOhm]

Yeah, I am not trying to change his mind. But I don't want some newb blowing up his shed (or house!), so I try to point out dumb/wrong advice.

Yea of course I was just warning you he'll continue for a long time so now your point is well made you can avoid wasting time continuing.

But yeah, for everyone: don't take a chance with grossly bloated cells, even if fire isn't super likely (unlike NMC) electrolyte decomposes to the nastiest acid I know of... Just replace the cells who are in this state.

I had a friend nuke a 20kw CALB? pack years ago when some solid copper bus bars caused the cell casing/terminal to crack due to high cycle fatigue. It took 5 years or so, but the damage was pretty spectacular... Had a friend nearly kill himself working alone on an EV because 90VDC is "low voltage". Fools will as fools do.

Ah, thanks for the real life experience I've seen a lot of metal fatigue cracks on other things (mainly in aeronautics) but I didn't find one for lithium batteries even if it was a certainty to happen as they have a cyclic behaviour and use aluminium and copper.

 

[BiduleOhm]

Yeah I'm done here. I just to hope to high heaven that no newbie hurts themselves (or worse) by following his insane advise.

Yeah of course, it was just a friendly advice to avoid you wasting too much time continuing

Again @all: If you have cells in this state then replace them, it's not worth taking a chance.

 

[Luthj]

If the cells are well restrained, solid copper bus bars can work okay. But that typically needs a major fixture. Something like 6psi on the wide sides of the cells. I would personally go with layered bus bars if I make my own.

In the case of the 20kw pack, the cells were just sitting on the ground with no restraining mechanism, and some mild corrosion caused that bus bar to heat cycle more than the others.

 

[Frank in Thailand]

@BiduleOhm , I never said metal fatigue doesn't exist.
The mild swelling and contraction won't give metal fatigue in copper busbar, during their lifetime (10-15 years) that's something different.

You insist that it will break a bus-bar and course extensive problems.
I simply disagree.

One thing we both did agree on, is that it is best to have the cells tight together to avoid any friction.

The cells of @ecualibrium weren't "overvoltaged" not beyond the 4.2 volt the cell can handle.
My cells didn't even reach 3.6volt
constant current of 3.5 amp (total 12w) where enough to pillow the cell in less then 8 hours.
(The cell was below 3.35 at the start of the 8 hours)

we are not talking about heavy abused cells.

We talk about cells that are bloating during normal solar usage.
That is mostly low charge and discharge

Sure, the CALB cell you see in the video that bloated during the short...
I won't advise to use that one, even if it still works.

Cells like mine and @ecualibrium are perfectly safe to use.

Please do the fear preaching somewhere else as it is costing other people their money while it it totally unnecessary.

If someone did abuse their cell and as result it is bloating, you are correct.

This is normal usage, and normal (unwanted) behaviour to have bloating cells.
Those cells can be used, like the others, for ages.

 

[BiduleOhm]

If the cells are well restrained, solid copper bus bars can work okay. But that typically needs a major fixture. Something like 6psi on the wide sides of the cells. I would personally go with layered bus bars if I make my own.

In the case of the 20kw pack, the cells were just sitting on the ground with no restraining mechanism, and some mild corrosion caused that bus bar to heat cycle more than the others.

Yep, exactly what I was saying in the other thread ^^ either use rigid busbars but then mount the cells rigidly too, or use non-rigid busbars.

I'm curious: it's the busbar who failed or the cell post/internals connection?

 

[heirloom hamlet]

Yeah, I am not trying to change his mind. But I don't want some newb blowing up his shed (or house!), so I try to point out dumb/wrong advice.

I had a friend nuke a 20kw CALB? pack years ago when some solid copper bus bars caused the cell casing/terminal to crack due to high cycle fatigue. It took 5 years or so, but the damage was pretty spectacular... Had a friend nearly kill himself working alone on an EV because 90VDC is "low voltage". Fools will as fools do.

If I had some low criticality application away from humans, where the cost of failure was minimal. Sure, I might use bloated cells. Running some remote lighting, electric gates, maybe a water pumping station in a field somewhere. But in an RV? Home? Garage? Sorry, seen enough electrical fires...

I'm not using it, I just have to figure out how to replace a single cell affordably.
I have lots of cells and time to get things right before they officially needed to perform. Thanks for all the input from everyone. Even the nayser. It's all useful in the learning process. I've learned a ton this morning alone.

 

[Luthj]

I'm curious: it's the busbar who failed or the cell post/internals connection?

If memory serves it was the terminal/post. These were 1/4" thick bus bars. If the bars were thinner they would have flexed instead of the cell terminal. In that case the copper may have work hardened and cracked. Hard to say without knowing the strain and hole diameter. For a typical short bus bar the buckling tendency on anything over 1/8" probably is less than the cells terminal strength, so the terminal will give first. Anything more than a degree or so of repeat twisting can damage cell terminals. There are so many designs though... Best to follow manufacturers recommendations and best practices. We are talking about 10 years and $$$$$ in many cases.

 

[sremick]

If the cells are well restrained, solid copper bus bars can work okay. But that typically needs a major fixture. Something like 6psi on the wide sides of the cells. I would personally go with layered bus bars if I make my own.

Yeah research I've done since ordering my cells has moved me towards picking up some braided busbars vs. using the ones Xuba is including with my cells. Especially since my kit will be mobile (but it will also be well-restrained).

 

[BiduleOhm]

@BiduleOhm , I never said metal fatigue doesn't exist.
The mild swelling and contraction won't give metal fatigue in copper busbar, during their lifetime (10-15 years) that's something different.

You insist that it will break a bus-bar and course extensive problems.
I simply disagree.

See, even with a real life example you'll not move from your PoV, I can't do anything at this point. This post will be the only one I'll make about that as to not waste time, have a nice day

We talk about cells that are bloating during normal solar usage.

I tought cells didn't swell according to you? ? (no need to answer)

 

[BiduleOhm]

If memory serves it was the terminal/post. These were 1/4" thick bus bars. If the bars were thinner they would have flexed instead of the cell terminal. In that case the copper may have work hardened and cracked. Hard to say without knowing the strain and hole diameter. For a typical short bus bar the buckling tendency on anything over 1/8" probably is less than the cells terminal strength, so the terminal will give first. Anything more than a degree or so of repeat twisting can damage cell terminals. There are so many designs though... Best to follow manufacturers recommendations and best practices. We are talking about 10 years and $$$$$ in many cases.

Ok thanks, that's exactly what I thought, the post is more likely to fail before the busbar, even if the busbar can fail too depending on the exact design of course. Interesting to see it was a copper post, aluminium is even more prone to metal fatigue.

There's also the internal connections who are likely to fail but when they fail the damage isn't really apparent at first glance as it's just a loss of capacity (that's also why they the cells tend to lose less capacity with cycles if they are clamped with some pressure).

 

[Frank in Thailand]

https://gwl-power.tumblr.com%2Fpost%2F65416024643

This is a serious situation

 

[HRTKD]

BiduleOhm, sremick and luthj, thank you for fighting the good fight. I'll go back and like your posts. Too bad I can vote down a post for 50 lines of bloviating nonsense.

 

[Ampster]

Why active?

Doesn’t passive offer all the same benefits with a simpler system just at the cost of a tiny bit of wasted power??

If i understand the differences between active and passive it is that active balancing uses less power because it transfers energy between cells. That would be from high voltage to low voltage near the top and bottom.

 

[Frank in Thailand]

BiduleOhm, sremick and luthj, thank you for fighting the good fight. I'll go back and like your posts. Too bad I can vote down a post for 50 lines of bloviating nonsense.

Feel free to report
Just that you disagree doesn't make it nonsense.
That lithium ion gets dangerous doesn't make lifepo4 dangerous.

If anyone does not feel comfortable to use a bloating cell, don't use them!

Just don't throw them away.
That would be sad.
I'm happy to give them a new long, long life.
They aren't defective or dangerous.
Unless it is the result of abuse.