Blown it's top ? Why?

[Borneoboy]

One of my newish 90 A/HR LIPO4 has blown the pressure release and is indicating 0.57 volts only...
Completely scrap ?
And never happened to me before, so I have little idea why (apart from faulty cell presumably).
Anyone suggest causes ?

 

[MisterSandals]

I have never seen one blow like that without being charged or discharged.
Is your BMS for LIPo or LiFePO4 cells?

The connections on your cells are terribly corroded and probably related to any problems you are having:

 

[Lt.Dan]

Corrosion and LifePO4 are not too common from what I've seen unless the environment was poor. Where do you live?

 

[Bud Martin]

OP lives on Borneo island in South East Asia.
OP should at least use tinned wires and terminals and better crimping.
Copper and Aluminium do not act well together

 

[Nobodybusiness]

One of my newish 90 A/HR LIPO4 has blown the pressure release and is indicating 0.57 volts only...
Completely scrap ?
And never happened to me before, so I have little idea why (apart from faulty cell presumably).
Anyone suggest causes ?

Almost looks like Brass busbars??

 

[Borneoboy]

I have never seen one blow like that without being charged or discharged.
Is your BMS for LIPo or LiFePO4 cells?

The connections on your cells are terribly corroded and probably related to any problems you are having:

View attachment 150878View attachment 150879

Yes, I noticed the "corrosion" which hasn't occurred on any other of my 24 cells (other set ups) ... Could some chemical have come out of that cell to cause it ?
They are only six months old.
Daly BMS supposed to be for LIPO4.

Almost looks like Brass busbars??

Busbars supposed to be tinned copper and came with the cells.
They are quite silver colour in real life. Think the flash gave them a yellow tinge ...

 

[Borneoboy]

OP lives on Borneo island in South East Asia.
OP should at least use tinned wires and terminals and better crimping.
Copper and Aluminium do not act well together

Noted your helpful comments!
Crimping still not mastered I'm afraid...
You mean the terminals supplied with the cells are all aluminium these days ? I always try to use copper lugs, but will have to rethink that one ...

 

[Any name you wish]

Does the vent point out like it blew out or is it pointed in like something punctured it? Also, it appears you have this contained in a plastic box, what does the lid look like? What covers the terminals?

 

[Borneoboy]

Does the vent point out like it blew out or is it pointed in like something punctured it? Also, it appears you have this contained in a plastic box, what does the lid look like? What covers the terminals?

All rather flimsy plastic at the moment - lid and box.
Seems to have blown out (upwards), through the blue cover and also through the transparent thin plastic just above that.
Little specks of blue on the nearby terminal, looking like typical aluminium corrosion.
I have replaced that one cell and all working normally again.
Let's see how long it all lasts ...has rather dented my faith in these batteries however.

 

[SilverbackMP]

All rather flimsy plastic at the moment - lid and box.
Seems to have blown out (upwards), through the blue cover and also through the transparent thin plastic just above that.
Little specks of blue on the nearby terminal, looking like typical aluminium corrosion.
I have replaced that one cell and all working normally again.
Let's see how long it all lasts ...has rather dented my faith in these batteries however.

Your wiring looks like a 15 year old hooked up a twenty year old stereo in a 50 year old vehicle using gum wrappers. These aren’t square 6v flash light batteries.

 

[Any name you wish]

All rather flimsy plastic at the moment - lid and box.
Seems to have blown out (upwards), through the blue cover and also through the transparent thin plastic just above that.
Little specks of blue on the nearby terminal, looking like typical aluminium corrosion.
I have replaced that one cell and all working normally again.
Let's see how long it all lasts ...has rather dented my faith in these batteries however.

So no melting or signs of chemical on the lid? It just popped then?

 

[mikefitz]

What charging voltage are you using?
My guess re the blowout, is that BMS protection did not occur due to the poor condition of the sence wire connections to the cells.
The cells seem somewhat bloated, perhaps due to overcharge.

 

[S Davis]

It looks like a couple of the cells have expanded and contracted enough to separate the cell case where it meets the top.

 

[RCinFLA]

The picture looks like an inward puncture due to someone or something jabbing it from the outside.



An internal overpressure blows the burst port outward, not inward. You will definitely know when a cell experiences a pressure port burst. It will spit out its guts.

I have seen unscrupulous vendors take a needle and puncture a small hole in pressure port at the very edge, so it is not obvious, to release cell bloating gas. But nothing so obvious as the picture shows.

Once a cell is open to air, the solvent in electrolyte will evaporate over some time. Cell is dead if that happens. Humidity intrusion also interacts with lithium destroying the cell.

 

[Borneoboy]

Your wiring looks like a 15 year old hooked up a twenty year old stereo in a 50 year old vehicle using gum wrappers. These aren’t square 6v flash light batteries.

Actually an 80 year old and don't be so rude - we do our best.

 

[Borneoboy]

So no melting or signs of chemical on the lid? It just popped then?

No melting or signs of heat.

 

[Borneoboy]

No melting or signs of heat.

But some signs of chemical powder on the nearest terminal.

 

[Borneoboy]

The picture looks like an inward puncture due to someone or something jabbing it from the outside.

An internal overpressure blows the burst port outward, not inward. You will definitely know when a cell experiences a pressure port burst. It will spit out its guts.

I have seen unscrupulous vendors take a needle and puncture a small hole in pressure port at the very edge, so it is not obvious, to release cell bloating gas. But nothing so obvious as the picture shows.

Once a cell is open to air, the solvent in electrolyte will evaporate over some time. Cell is dead if that happens. Humidity intrusion also interacts with lithium destroying the cell.

Very interesting and informative,thank you.
But there are some signs of chemical outside...not much, but it a high humidity environment here.

 

[Borneoboy]

What charging voltage are you using?
My guess re the blowout, is that BMS protection did not occur due to the poor condition of the sence wire connections to the cells.
The cells seem somewhat bloated, perhaps due to overcharge.

Charging with two 100 watt panels (just moved into full sun) and giving 30 to 40 volts and a maximum of 5.9 amps at midday.
Most of the cells are slightly bloated.

 

[Borneoboy]

Your wiring looks like a 15 year old hooked up a twenty year old stereo in a 50 year old vehicle using gum wrappers. These aren’t square 6v flash light batteries.

your profile looks interesting (blank/not available) and you've been on here a whole year ...what an old timer !