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Be careful

Kokireg

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Joined
Apr 30, 2022
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36
a little post to give you a feedback
I made a LIFEPO4 battery 8 months ago for my camper.
I bought on aliexpress from a well known supplier 4 cells 3.2V of 320Ah.
I took a BMS DALY 200A.
I did everything right following the advice of the forum and youtube videos (balancing, battery construction, BMS configuration, ....)
On this battery there were the 12V lights of my VAN and a 2000W converter. (12->220V).
Battery installed under the passenger seat.
This battery was charged with a victron mppt and solar panel that provided max 20A.

Everything worked great for 8 months.
But 2 days ago when we were leaving for a weekend with the vehicle, a whistling noise under the seat.
White smoke started to appear.
We stopped and a thick white smoke came out for about 30 minutes.
A liquid was coming out of a cell and there was a strong release of heat that melted the battery tower.

I don't understand what happened.

The DALY salesman tells me that it is a problem with a poor quality cell.
The cell seller (I didn't give his name but it starts with Lit....) tells me that it's because the battery has been used too long. incomprehensible ????????

if anyone has an idea of the cause?
IMG_20220429_205622.jpgIMG_20220429_204153.jpgIMG_20220429_204236.jpg
 
That is scary! Was anything running, i.e. inverter, loads when that happen?
How did you put out the fire?
 
there was just I 12->220 converter that worked to power a refrigerator. This creates a consumption of about 10A max on the battery.
But it was recharging because I was driving a I have a victron DC/DC converter that provided it with about 20A.
So there was a recharge of about 10A on the battery.

There was no Fire (flame). Just white smoke and a lot of heat.
The firemen and policemen were afraid.

We waited and after 30 minutes the smoke left.

The cells remained boiling for several hours.
 
You are lucky that there is no fire.
If you look at the vent seal of each battery, did any one of them pop off?
Very sorry this happen to you and good thing that you did not get hurt.
 
No, there are no pierced event seals.

On the other hand we can see that on 2 lower corners of a cell, there are 2 holes that have opened.
 
(I didn't give his name but it starts with Lit....)

LitoKala, let me guess :) . If I'm right they are known for selling low-grade cells. But I have some doubts that this is caused by the cell itself.

How were these mounted? With terminals on top or on one side? What was the enclosure? How were these secured in place?

Any chance that something made a short circuit on the cell terminals?
 
Wow!
Given that this happened eight months after installation makes the culprit more than likely a bad cell. Did you ever test the cell voltages manually to confirm the BMS was operating properly.
 
Without wanting to say that I am good, I think that everything was done in the right way.
The cells were laid vertically, the bollards on top. Everything was insulated before special tape and an insulating plate was put on top.
Yes, the cells had been tested and balanced.
The bms was working but it's true that one cell always had a little higher voltage than the others when I looked at the data despite the balance.
 
Assuming the cell didn't accidently get shorted, this can happen if the cells were "ever" charged below zero at a high enough charge, which is very small - so don't even think about it. One of the problems with second hand cells is that you don't know if they have ever been charged below Zero. They form dendrites that can short the battery after they have warmed up and been charged a few times properly. Sometimes 100's of charges after. I have data on battery safety that I will dig out later with this example.
Good to hear that you are OK with no fire.. LiFePO4 smoke with heat (as you have found) but are much less likely to burst into flames like a li-ion would.
You should always minimise the risk of fire by putting the batteries in a fire resistant box and if they power a building, keep then outside in this box with proper temperature control. In a vehicle, make sure the vibrations are not going to shake anything loose. Check them each month for bloating, which is a sign that something isn't right.
Lastly - don't discharge below or charge above the manufactures specification. Most people only charge to 90% and discharge to 10% absolute min.
Generally speaking, as long as you treat them correctly, they are usually quite safe in my opinion.
 
Here is some reading for you.. Page 98, "The cell was removed from the climate chamber for post-mortem analysis. The reason for the failure was, most likely, due to the fact that the cell was cycled at sub-zero temperatures at 1Cnom. Charging at sub-zero temperatures can result in the plating of lithium onto the negative electrode (anode). If dendrites form and puncture the separator it can lead to a short circuit."
 

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the cell was cycled at sub-zero temperatures at 1Cnom.

One important thing to add here is that this is only possible by substantially increasing the charging voltage. At low temperatures, the internal resistance goes way up which in itself prevents a large current from flowing. I tested that:

 
Rather than Postulating, Theorising or just tossing about Conjecture... Let get this sorted. (Cell quality etc = Conjecture which serves NO PURPOSE but to irritate the Victim and those seeking FACTS.)

An important Fact: This is Mobile Installation, Appears that the cells were "not bound" which can subject terminals to movement.
Binding Cells is not just "compressing" it is intended not allow the cells to move separately/independently. The Terminals will NOT handle movement.

From the photo's it appears that 1 Cell went into a thermal failure which began to spread to neighbouring cells. Ultimately this was a single cell failure that initiated the problem. Several things can actually cause this and Forensic Diagnosis is difficult. The Terminal may have separated internally enough to short, a Hit or Puncture of the case (not evident), a Short Circuit at the Cell Busbars, even the Busbar being loose with a regular draw (even just 10A) can cause heat (and you'd be surprised how much).

TWO Most Likely causes:
1) Busbar or Terminal connection loosened creating an ARC situation which can generate a great deal of heat fast (Heavy Welders are DC for a Reason) (one indicator is cell voltage reading by BMS not being correct)
2) Terminal Failure resulting from movement, vibration and shaking. Stress on the outside of the terminal against the fine "foils" inside do not take this well. This is the primary reason for Binding Prismatic Cells.

CHARGING ?
This battery was charged with a victron mppt and solar panel that provided max 20A.
This is well within spec and should have not overdriven charge etc.
But it was recharging because I was driving a I have a victron DC/DC converter that provided it with about 20A.
Alternators ! UGH !! They can be the most miserable things to get around, in a "general sense" they are terrible for LFP, given them Brute Force Lead and fine but not any Lithium Based battery. Many go with the "Cheaper & Simpler" route as you did with great success but there are Gotcha's for workarounds. It simply adds more failure & control points to be aware of. The Marine folks have really got a "Bead" on using alternators to charge, they usually go with aftermarket.

The Simplest solution is as you did, leave a Lead Battery for the Alternator to do it's normal charging and TAP off that to an ISOLATED Orion-Tr Smart DC-DC charger

ALSO Check the Victron Charger to see what if anything is amiss with the settings, also check it's voltages in/out with a MultiMeter, IT could have failed causing this as well. DO NOT TRUST THE CHARGER UNTIL FULLY TESTED !

Hope it helps, Good Luck
 
a little post to give you a feedback
I made a LIFEPO4 battery 8 months ago for my camper.
I bought on aliexpress from a well known supplier 4 cells 3.2V of 320Ah.
I took a BMS DALY 200A.
I did everything right following the advice of the forum and youtube videos (balancing, battery construction, BMS configuration, ....)
On this battery there were the 12V lights of my VAN and a 2000W converter. (12->220V).
Battery installed under the passenger seat.
This battery was charged with a victron mppt and solar panel that provided max 20A.

Everything worked great for 8 months.
But 2 days ago when we were leaving for a weekend with the vehicle, a whistling noise under the seat.
White smoke started to appear.
We stopped and a thick white smoke came out for about 30 minutes.
A liquid was coming out of a cell and there was a strong release of heat that melted the battery tower.

I don't understand what happened.

The DALY salesman tells me that it is a problem with a poor quality cell.
The cell seller (I didn't give his name but it starts with Lit....) tells me that it's because the battery has been used too long. incomprehensible ????????

if anyone has an idea of the cause?
View attachment 93161View attachment 93162View attachment 93163
Do you have pictures of the assembled battery? Progress of the build shots? Something we might be able to analyze and determine a flaw hat may have caused this?
 
Bud Martin; I have yet to see any report of a LiFePo cell actually catching fire. Smoke, liquid boiling, enough heat to cause a fire on nearby combustibles. But not the cells themselves.Correct me with a link as I'm curious.
 
a little post to give you a feedback
I made a LIFEPO4 battery 8 months ago for my camper.
I bought on aliexpress from a well known supplier 4 cells 3.2V of 320Ah.
I took a BMS DALY 200A.
I did everything right following the advice of the forum and youtube videos (balancing, battery construction, BMS configuration, ....)
On this battery there were the 12V lights of my VAN and a 2000W converter. (12->220V).
Battery installed under the passenger seat.
This battery was charged with a victron mppt and solar panel that provided max 20A.

Everything worked great for 8 months.
But 2 days ago when we were leaving for a weekend with the vehicle, a whistling noise under the seat.
White smoke started to appear.
We stopped and a thick white smoke came out for about 30 minutes.
A liquid was coming out of a cell and there was a strong release of heat that melted the battery tower.

I don't understand what happened.

The DALY salesman tells me that it is a problem with a poor quality cell.
The cell seller (I didn't give his name but it starts with Lit....) tells me that it's because the battery has been used too long. incomprehensible ????????

if anyone has an idea of the cause?
Thanks for posting Kokireg - obviously could have been a lot worse. What sort of battery tower were you using to house the cells? Looks like the faulty cell was at one end of the series and against the seat frame. So perhaps movement or vibration over time eventually punctured the aluminum housing of that cell? Keen to know as building one for a boat using cable instead of rigid bus bars to connect the series but doesn't sound like this was an issue with the terminals becoming damaged from movement.
 
a little post to give you a feedback
I made a LIFEPO4 battery 8 months ago for my camper.
I bought on aliexpress from a well known supplier 4 cells 3.2V of 320Ah.
I took a BMS DALY 200A.
I did everything right following the advice of the forum and youtube videos (balancing, battery construction, BMS configuration, ....)
On this battery there were the 12V lights of my VAN and a 2000W converter. (12->220V).
Battery installed under the passenger seat.
This battery was charged with a victron mppt and solar panel that provided max 20A.

Everything worked great for 8 months.
But 2 days ago when we were leaving for a weekend with the vehicle, a whistling noise under the seat.
White smoke started to appear.
We stopped and a thick white smoke came out for about 30 minutes.
A liquid was coming out of a cell and there was a strong release of heat that melted the battery tower.

I don't understand what happened.

The DALY salesman tells me that it is a problem with a poor quality cell.
The cell seller (I didn't give his name but it starts with Lit....) tells me that it's because the battery has been used too long. incomprehensible ????????

if anyone has an idea of the cause?
View attachment 93161View attachment 93162View attachment 93163
I’m not saying this is how it happened but the only time I have seen anything like that is a shorted cell. Either shorted internally or to the frame somehow.

I’m glad everyone is OK.
 
Without wanting to say that I am good, I think that everything was done in the right way.
The cells were laid vertically, the bollards on top. Everything was insulated before special tape and an insulating plate was put on top.
Yes, the cells had been tested and balanced.
The bms was working but it's true that one cell always had a little higher voltage than the others when I looked at the data despite the balance.
do you know if it was that cell? (numbering starts from the main negative terminal)
 
So some clarifications
For the charge with the alternator there is no problem because I go through a charger dc/dc victron energy parameterized for lifepo4 so no problem of high voltage for the charge. It is not connected to the alternator directly.

For the cells they were all strapped together and blocked under the seat. They could not move.

They were new batteries.
They were never charged at low temperature because the BMS was configured to do so. (Charge cut off below 3 degrees Celsius)

Yes, I think the cell that had a fault was the one that had a slightly higher voltage than the others when I checked on the DALY application.

The terminals did not loosen because when I removed the battery I took the cells apart and they were all tight.

The offending cell was the one on the other side of the + and - terminals.

We now see 2 holes at the bottom corners. The upper protection cap between the terminals did not pierce.
 
here are some photos in the process of being assembled last year.
On the pictures there are some wooden plates missing that I added where the cells could touch the seat frame.
The cells were completely surrounded by insulating tape (https://fr.aliexpress.com/item/3292..._list.0.0.71265e5bvF5aBg&gatewayAdapt=glo2fra)
and then power tape and plywood.

The battery was installed in September 2021 and I left with my camper for 1 full week. Then the camper was in the garage for mechanical problems for 1 month.
Then I left with it since the beginning of the year 3x 3 days without worries.

I do not think that the battery is then move because they were really well wedged.

In any case thank you very much for your messages of comfort.

My insurance company will contact me this week to see if they will participate in the work.

I'm going to make a new battery Lifepo4.
At the moment they only have 280 Ah in stock, too bad I would have liked 320 or 304.
Then I also think of taking a BMS but not a DALY. I will go for a JK, the JK-B2A8S20P-HE.

IMG_20210916_121308.jpgIMG_20210916_121314.jpgIMG_20210916_121324.jpgIMG_20210908_192628.jpg
 
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