Overcharged and Swollen

[OldSmokey]

Looking for an honest opinion here. I recently bought a set of 280ah EVE cells and really screwed up while trying to top balance. I had them sitting in parallel for about 4-5 days, trying to top balance to 3.6v. They really weren’t progressing(due to my small 5a power supply) and I guess I got a little impatient. I put them in series and tried to charge them up to 14v. After that I was gonna go back to parallel to finish it off. Well last night I went to bed with them around 13.5v. I guess they took off overnight and I woke up to 17.6v(I know, should’ve been using a BMS). Of course in the process, they swelled up.

I got the pack down to normal levels at this point. My question is whether or not they’re too far gone or too dangerous to use. Believe me, I’m sick over the situation.

 

[JMc]

Man that sucks. Your post reminds me of the foodie forums where people leave a huge expensive roast out on the counter overnight and then ask if it’s still safe to eat. The responses are all over the map ranging from “Throw it out!” to “Sure go ahead and cook it, I do it all the time”. It all boils down to your personal tolerance for risk.

 

[OldSmokey]

Man that sucks. Your post reminds me of the foodie forums where people leave a huge expensive roast out on the counter overnight and then ask if it’s still safe to eat. The responses are all over the map ranging from “Throw it out!” to “Sure go ahead and cook it, I do it all the time”. It all boils down to your personal tolerance for risk.

Yea I know. I guess the ultimate question is, what does that risk involve? If it’s just degraded capacity/life cycle, I’d be okay running it for a while. If it poses a safety risk.... that’s a different story.

 

[Frank in Thailand]

Welcome to the cushion club...

Sadly I have a few like that.

And am using them without real issues.
Yes, they are slightly delaminated.
With compression it will get a bit better in a few months.
(You will notice that the nuts used for the compression can be tightened more easy.)
They won't get totally flat again.

Other thing for me was adjusttbe the busbars, as they didn't fit anymore.

I've done several capacity tests, and notice that the capacity drop is just a little bit.

For solar use, that is kind of slow charge and discharge, it's OK to use.
For electric vehicle... Probably not.

Some might say it's dangerous and bla bla bla.
They are mistaken lithium Polymer battery for LiFePO4.
LiFePO4 won't explode or catch fire.
Also no thermal meltdown.

Yes,they got hurt.
How much? Only time will tell.
In 5 years or so you might notice capacity difference.
At the moment it's small.
280 has become 270-275Ah.
Nothing spectacular.

For me it was my 152Ah cells.
(Almost all 48)
Just finished capacity testing, this is one year after I abused them.
144-149Ah.
Nothing spectacular, yet.

Edit: my 12v (4 cells) didn't get abused. They tested 148-151Ah, but have had way less cycles)

Real life data.
Real usage 24-7 for +350 days.

That's all the scientific data I can provide to you.

I do have one real pillow....
Accedently short one 280Ah cell.
First day looked OK.
Second day.. 0.04v
And when I released the compression...
Pillow!!!
I was surprised the emergency vent didn't go, as it's a real round pillow now.
About double normal abused charge pillow...

 

[jwelter99]

Those cells should be recycled. They are now considered very dangerous for normal use.

 

[Frank in Thailand]

Those cells should be recycled. They are now considered very dangerous for normal use.

Please provide scientific data how they are dangerous, more dangerous then they where before becoming slightly delaminated.

As I wrote don't mistake LiFePO4 for phone lithium battery.
Those are dangerous and known to catch fire spontaneous.
Same as E-bike etc.

That's lithium polymer.
NOT LiFePO4. !!!

Not to be negatieve towards you, but without scientific data to back up your claim, it's just the "bla bla bla" I wrote about, from people who don't know the difference.

Pitbulls are dangerous.
Let's kill all the dogs.

 

[~Yuri~]

Those cells should be recycled. They are now considered very dangerous for normal use.

Please justify your "very dangerous". What are their dangers?

 

[OldSmokey]

Welcome to the cushion club...

Sadly I have a few like that.

And am using them without real issues.
Yes, they are slightly delaminated.
With compression it will get a bit better in a few months.
(You will notice that the nuts used for the compression can be tightened more easy.)
They won't get totally flat again.

Other thing for me was adjusttbe the busbars, as they didn't fit anymore.

I've done several capacity tests, and notice that the capacity drop is just a little bit.

For solar use, that is kind of slow charge and discharge, it's OK to use.
For electric vehicle... Probably not.

Some might say it's dangerous and bla bla bla.
They are mistaken lithium Polymer battery for LiFePO4.
LiFePO4 won't explode or catch fire.
Also no thermal meltdown.

Yes,they got hurt.
How much? Only time will tell.
In 5 years or so you might notice capacity difference.
At the moment it's small.
280 has become 270-275Ah.
Nothing spectacular.

For me it was my 152Ah cells.
(Almost all 48)
Just finished capacity testing, this is one year after I abused them.
144-149Ah.
Nothing spectacular, yet.

Edit: my 12v (4 cells) didn't get abused. They tested 148-151Ah, but have had way less cycles)

Real life data.
Real usage 24-7 for +350 days.

That's all the scientific data I can provide to you.

I do have one real pillow....
Accedently short one 280Ah cell.
First day looked OK.
Second day.. 0.04v
And when I released the compression...
Pillow!!!
I was surprised the emergency vent didn't go, as it's a real round pillow now.
About double normal abused charge pillow...

Thanks. That makes me feel a lot better about the situation.

 

[Frank in Thailand]

My cells, all freshly tested.

You can see the different levels of pillowing.




In the year I have them, I reinstalled too many times.
At the start with the crappy M6 screws provided.
That is a bad idea to use.

I changed to studs, a lot better, but damage was done.

Some thread was ripped out, beyond repair.
New M8 does wonders

 

[ereams65]

Yikes! DId you check each cell, did they individually get to 4.4v? I would drain them to their lowest voltage and let them rest. Then, I would compress them, gently, and recharge each cell and then measure resistance. Hook a BMS up and then do a discharge test. BTW, I would be do all of this testing outdoors in a safe place. I had a Li-Ion cell spike up on me and I moved it out to my fire pit until I was comfortable it was ok. That way, if thermal runaway started, it could burn itself out away from anything else.

 

[jwelter99]

Please provide scientific data how they are dangerous, more dangerous then they where before becoming slightly delaminated.

As I wrote don't mistake LiFePO4 for phone lithium battery.
Those are dangerous and known to catch fire spontaneous.
Same as E-bike etc.

That's lithium polymer.
NOT LiFePO4. !!!

Not to be negatieve towards you, but without scientific data to back up your claim, it's just the "bla bla bla" I wrote about, from people who don't know the difference.

Pitbulls are dangerous.
Let's kill all the dogs.

When a cell is swollen that much things internally move further then designed (the 1mm +/-1mm in the specs) and therefore get stressed. Once stressed you have no idea over the actual capacity or safety of the cell. It has been damaged.

The only thing not known is how serious is the damage - it could last 3000 cycles without issues. It could short out on the next full charge or discharge cycle.

Best case is it fails open, worse case is it shorts internally and causes a fire or melt down.

And this is why they should not be used.

 

[cinergi]

17.6 = done. You went well over 4 volts (4.4 average) which destroys the electrolyte. I would be very concerned about safety at this point because I don't know what the implications of bad electrolyte are. In reality, no one here has sufficient experience with cells that sat at 4.4v to tell you what's going to happen to them if you keep using them. All we know is that LFP electroltye quickly dies above 4v and that swelling may cause problems with the anode/separator/cathode roll.
If you can use them in a container outside where if they set on fire it's no big deal, go for it. We'll all learn a little from that

 

[Frank in Thailand]

When a cell is swollen that much things internally move further then designed (the 1mm +/-1mm in the specs) and therefore get stressed. Once stressed you have no idea over the actual capacity or safety of the cell. It has been damaged.

The only thing not known is how serious is the damage - it could last 3000 cycles without issues. It could short out on the next full charge or discharge cycle.

Best case is it fails open, worse case is it shorts internally and causes a fire or melt down.

And this is why they should not be used.

Apples and oranges.
LiFePO4 can short internal, but won't give fire or melt down.
Lithium polymer... Can.

Correct warning for lithium Polymer.
For LiFePO4, it's nonsense.

They got pillowed because they where not installed according specifications : clamped together.

My shorted cell stayed in shape till I released the compression.
Then it delaminated.

Everyone who is using the aluminium housing cells without compression is stressing them beyond specifications.
According to you all should recycle?

Then please....
Can I have them??

 

[Frank in Thailand]

17.6 = done. You went well over 4 volts (4.4 average) which destroys the electrolyte. I would be very concerned about safety at this point because I don't know what the implications of bad electrolyte are. In reality, no one here has sufficient experience with cells that sat at 4.4v to tell you what's going to happen to them if you keep using them. All we know is that LFP electroltye quickly dies above 4v and that swelling may cause problems with the anode/separator/cathode roll.
If you can use them in a container outside where if they set on fire it's no big deal, go for it. We'll all learn a little from that

Apples and oranges.

Eve 280Ah pouches aren't rolls.
Their internal structure is different.

Please provide us with information about your claim that 4.4v destroyed the electrolyte!!
(Not kidding, I really, really do like to know.
I'm starting to get quite an expert on Lithium types and their structure and different chemical composition.
The composition of the electrolyte is a gray area for me, not much available information.
Leaning new things every day, this might be it for today)

Please provide us with information about LiFePO4 cells catching fire.
(I doubt you be able!)

There are tons of YouTube video's where they put LiFePO4 cells in fire, shot them, used an ax, full short (reached 1300A on 100Ah cell), droped them from high building, etc.
Just about all the abuse you could possibly think off.
And none of it made fire, melt down or explosion.

Also tons of videos with lithium polymer that explode, catch fire and all the other things I read warnings about.

I know. It's difficult.
Both are called lithium.
But absolutely not the same, especially on safety!!

One of the reason I always use LiFePO4 and lithium polymer, never just refer to as "lithium" because this strange result, that people think the dangers of one type are applicable to all.

 

[jwelter99]

Apples and oranges.
LiFePO4 can short internal, but won't give fire or melt down.
Lithium polymer... Can.

Correct warning for lithium Polymer.
For LiFePO4, it's nonsense.

They got pillowed because they where not installed according specifications : clamped together.

My shorted cell stayed in shape till I released the compression.
Then it delaminated.

Everyone who is using the aluminium housing cells without compression is stressing them beyond specifications.
According to you all should recycle?

Then please....
Can I have them??

I realize you have a bunch of cells that have been damaged and you really want them to still be usable -- but the fact is they are no longer safe. They need to be safely recycled. It sucks but that doesn't change it being true.

This is completely wrong info you are spreading. They got pillowed as overcharged and internally stressed. If compressed they still would be damaged. You likely would have seen any side not compressed show pillowing. The wide sides are just more prone to it and therefore the compression suggestion.

An internal short is not chemistry related. The outcome is the same. Extreme heat that leads to venting, melting, and potentially fire. The cell itself will not burst into flames due to chemistry type but the heat from the short will cause fire. You should know this due to the melt down in your pack.

 

[cinergi]

Apples and oranges.

Eve 280Ah pouches aren't rolls.
Their internal structure is different.

Please provide us with information about your claim that 4.4v destroyed the electrolyte!!
(Not kidding, I really, really do like to know.
I'm starting to get quite an expert on Lithium types and their structure and different chemical composition.
The composition of the electrolyte is a gray area for me, not much available information.
Leaning new things every day, this might be it for today)

Please provide us with information about LiFePO4 cells catching fire.
(I doubt you be able!)

There are tons of YouTube video's where they put LiFePO4 cells in fire, shot them, used an ax, full short (reached 1300A on 100Ah cell), droped them from high building, etc.
Just about all the abuse you could possibly think off.
And none of it made fire, melt down or explosion.

Also tons of videos with lithium polymer that explode, catch fire and all the other things I read warnings about.

I know. It's difficult.
Both are called lithium.
But absolutely not the same, especially on safety!!

One of the reason I always use LiFePO4 and lithium polymer, never just refer to as "lithium" because this strange result, that people think the dangers of one type are applicable to all.

The LFP cell will likely not set on fire (we have one example right here in the forums of a puncture that DID set it on fire, BTW). The stuff around it will (as you know). That's why I say put it outside and use it so you don't risk your property.

The electrolyte voltage:
* https://www.powerstream.com/LLLF.htm
* https://www.planetanalog.com/how-to-charge-lithium-iron-phosphate-rechargeable-batteries/
* https://www.mpoweruk.com/lithium_failures.htm

and plenty more ...

Edit: when I say "roll" I mean that these rectangular prismatic cells ARE a long strip of anode/separate/cathode rolled into a rectangular structure.

 

[Frank in Thailand]

The LFP cell will likely not set on fire (we have one example right here in the forums of a puncture that DID set it on fire, BTW). The stuff around it will (as you know). That's why I say put it outside and use it so you don't risk your property.

The electrolyte voltage:
* https://www.powerstream.com/LLLF.htm
* https://www.planetanalog.com/how-to-charge-lithium-iron-phosphate-rechargeable-batteries/
* https://www.mpoweruk.com/lithium_failures.htm

and plenty more ...

Edit: when I say "roll" I mean that these rectangular prismatic cells ARE a long strip of anode/separate/cathode rolled into a rectangular structure.

Thank you for your links.
They inform about general lithium,and not about the electrolyte.
I really do like to know in-depth research.
The general info sites, I could write one by head, with more accurate and detailed information then the 3 links.
Good for a newbie to start leaning.
Not really. As they treat all lithium as the same and then start to talk about difference.

They should not compare at all.
As they are so much different.
With different values, charge cycles, charge graphs, levels etc.

Starting by putting them in one basket is the root of the problem where people think LiFePO4 is dangerous, as lithium polymer is.
(Both have the word lithium, so both must be dangerous, yes?)

Too high voltage can/ will cause some lithium plating what will reduce the capacity.
Lithium plating is also the natural occurrence, the one that will reduce the capacity over time.
In 20 years it is theoretically over.
0% capacity left.

The folding of the layers looks like the mouse stairs (correct English?) you folded as a kid with 2 ribbon.

English is not my native language, perhaps that's called a roll. I don't know.

The fire?
That was me!!
I had fire a few months ago, and it wasn't from puncture.

Any short will cause heat.
Having a MDF sheet on top of that, will heat up the MDF to a level it starts smoldering.

Different materials have different response on heat.

The LiFePO4 didn't caused the fire.
A short wire did.
Capacity test on that cell (who got really hot!) Is 144Ah.
Run the test 3 times to be sure.

Several other cells who didn't got hot also are 144Ah.
All the cells will be used, none recycled.
it's easy to tell when it's not your money.

So no, puncture did not cause fire
Bare wire short (a lead from temperature sensor) did give fire

It also would have done that on lead acid, or any other power source.

Normally it would just glow.
Wood and something glowing...
Not a good combination.

 

[cinergi]

Thank you for your links.
They inform about general lithium,and not about the electrolyte.

Then you missed it. For example:

A LiFePO4 battery can be safely overcharged to 4.2 volts per cell, but higher voltages will start to break down the organic electrolytes.

There is a LOT of information about electrolyte breakdown for LFP above 4.2 volts.

The folding of the layers looks like the mouse stairs (correct English?) you folded as a kid with 2 ribbon.
View attachment 46354
English is not my native language, perhaps that's called a roll. I don't know.

The smaller and/or older ones may be like this (

) but here's a more recent teardown of 105ah cell:

The fire?
That was me!!
I had fire a few months ago, and it wasn't from puncture

I know. You're missing my point. If the cell has an internal short, it will get hot and set its surroundings on fire. Therefore, it's safer to put it outside.

 

[ereams65]

According to this white paper, you might both be correct; file:///C:/Users/ereams/Downloads/energies-12-04652%20(1).pdf


"It was demonstrated that a short-time overcharge of up to 5.0 V by high currents is the least destructive and does not lead to an irreversible changes in the cathode material. However, an increase in the upper limit of the potential to 6.0 V or a decrease in the charge current to 0.25 C leads to, both, the formation of surface layers of electrolyte decomposition products, an increase in the polarization of the battery, and to irreversible slowdown of the lithiation kinetics of the active material. Thus, despite the well-known tolerance of LiFePO4-based batteries to overcharge, a long overcharge time or high cut-off voltage leads to destructive changes in the cathode, and should be avoided."

The above was out of the conclusions. If you don't want to read the whole paper, basically they overcharged each test cell 25 times up to 5v, and on group 3, 6v. To the OP, the answer to his question is still not clear. Basically, this researcher is saying if you overcharge it with a high current, then it's probably not going to cause a permanent issue. But if it's low current, then it probably will.

 

[Gazoo]

Looking for an honest opinion here. I recently bought a set of 280ah EVE cells and really screwed up while trying to top balance. I had them sitting in parallel for about 4-5 days, trying to top balance to 3.6v. They really weren’t progressing(due to my small 5a power supply) and I guess I got a little impatient. I put them in series and tried to charge them up to 14v. After that I was gonna go back to parallel to finish it off. Well last night I went to bed with them around 13.5v. I guess they took off overnight and I woke up to 17.6v(I know, should’ve been using a BMS). Of course in the process, they swelled up.

I got the pack down to normal levels at this point. My question is whether or not they’re too far gone or too dangerous to use. Believe me, I’m sick over the situation.

Thanks for sharing your experience. I would be sick over this too. Not that it matters but those cells look like Lishen's?

As far as using them I wouldn't. As others have said there is no way to tell if there is internal damage that would cause an internal short. If they had bloated and the cell was convex then I think that would be internal gassing. However looking at the photo it appears as though the jelly roll expanded and caused the bulge since it's on the positive side. This probably means the jelly roll is damaged and is delaminated. There is no way to know for sure with out being able to see inside the cells but that's what it looks like happened.

If you do plan on testing please do it outside as cinergy suggested. All in all it's better to be safe then sorry.