Cell dead?

[henk_lifepo4]

Hi
I have a Battery with four 220 Ah cells with a JBD 200A BMS. It worked fine for about four years. The cells were normaly within 10 mV.
Recently i saw on the App that one cell had no voltage any more. I took the Battety apart and measured the cells with an YR1035+ . The cell with zero voltage has a resistance .15 and 0v. The other three have a resistance off .15 to .17 and all 3.30v.
Now i am wondering. I had expected the faulty cell to have a verry high resistance but 15 mOhm look good?
I tried to load the faulty cell with 3.6v and 5A. But it does not hold any power. So I think it is gone.
I do not understand how this is possible as the BMS should have stopped the decharche at an undervoltage of 2.5 v? Is the BMS maybe also not ok?. There has not been a Temp lower then 13° celcius or much heat and also not a high draw of Amps.

I plan to buy one new cell to fix the battery. Can I just connect it to the other three cells to topbalance and then rebuild the battery? After that I can measure the capacity to also check the other cells.?
Kind regards,
Henk.

 

[sunshine_eggo]

Hi
I have a Battery with four 220 Ah cells with a JBD 200A BMS. It worked fine for about four years. The cells were normaly within 10 mV.
Recently i saw on the App that one cell had no voltage any more. I took the Battety apart and measured the cells with an YR1035+ . The cell with zero voltage has a resistance .15 and 0v. The other three have a resistance off .15 to .17 and all 3.30v.
Now i am wondering. I had expected the faulty cell to have a verry high resistance but 15 mOhm look good?
I tried to load the faulty cell with 3.6v and 5A. But it does not hold any power. So I think it is gone.
I do not understand how this is possible as the BMS should have stopped the decharche at an undervoltage of 2.5 v? Is the BMS maybe also not ok?. There has not been a Temp lower then 13° celcius or much heat and also not a high draw of Amps.

I plan to buy one new cell to fix the battery. Can I just connect it to the other three cells to topbalance and then rebuild the battery? After that I can measure the capacity to also check the other cells.?
Kind regards,
Henk.

It is a dead cell. RIP.

Did this occur after a long period of storage, or was it in regular use?

The BMS is a battery device, not a cell device. The BMS likely did stop the discharge of the battery as that cell dropped below 2.5V, but it can't stop the cell from internally shorting and taking itself to 0V.

 

[henk_lifepo4]

That the cell is dead is clear. It was in use as it went dead.

I'm primilary concerned how to determin that the other three are OK.

 

[sunshine_eggo]

That the cell is dead is clear. It was in use as it went dead.

I'm primilary concerned how to determin that the other three are OK.

With all being at 3.30, they are likely fine. I would swap positions between the failed cell and another cell and confirm that the BMS itself hasn't malfunctioned and somehow drained the cell.

This simply looks like a spontaneous cell failure. It happens.

 

[Alkaline]

Happens, my grade "A" (when actually it was grade B.) died in 3 years, then it swells up too:

Thread 'Basen EVE 280 Dead as a Doornail in 3 years.'

Apr 15, 2024

Well in the back of my mind I knew it was only a matter of time, and now in less than 3 years the basen 280 EVE "Grade A" is dead. Checked the voltage and its 0 volts (or 0.012 v). Purchased from Alex Chen in Feb 2021...

This was in a 8s battery back with an overkill solar BMS, the other cells were at 3.34 volts so this one just died. Its also swollen beyond recognition. I made 3 of these 8s packs 1 with xuba cells, with 1 basen, and the other with Luyuan. The luyuan is the only one that is performing properly. All 3 battery packs were sold to a local guy who uses it in his camp and has...

• Alkaline
• Replies: 21
• Forum: DIY LiFePO4 Battery Banks

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