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My CALB cells have swollen

Usangira

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Joined
Dec 4, 2020
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101
Hi All,

Disappointed and frustrated.....
My charge controller broke down two weeks ago.... while I am in a process of getting another charge controller. I left my battery bank still connected but without load.

I went on safari and just came back only to find my CALB cells have swollen significantly just about to explode

I would like to understand what is driving this.....

Thanks, Innocent
 
Measure the cell voltage and you'll get your answers.

The battery bank being connected, but the load disconnected sounds like the broken charge controller was still connected. If so - it may have overcharged the cells. And it is normal to see swollen cells if they were overcharged.
 
Measure the cell voltage and you'll get your answers.

The battery bank being connected, but the load disconnected sounds like the broken charge controller was still connected. If so - it may have overcharged the cells. And it is normal to see swollen cells if they were overcharged.
No.... The charge controller was removed from the circuit since day 1.
So, the cells have swollen after the system stopped working. Before they were ok
 
Pictures? If it's all off and disconnected there shouldn't be any issues. Inverter is still connected - no stand-by draw or fault? What's the temperature like where the batteries are?
 
Pictures? If it's all off and disconnected there shouldn't be any issues. Inverter is still connected - no stand-by draw or fault? What's the temperature like where the batteries are?
The battery bank is always outside my house in the cage where temperature is between 22C - 32C. No ventilation issues
 

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How did you know your charger failed? Is this a PV SCC or a stand alone bench charger? If it’s a SCC it may have hit the cells with PV voltage, odd failure mode but still a concern.

Did the BMS ever disconnect the battery for cell high voltage?

What BMS are you running?

What is the outside temp lows? You thinking the cage never goes under 22c doesn’t make it so.
 
How did you know your charger failed? Is this a PV SCC or a stand alonebench charger?

Did the BMS ever disconnect the battery for cell high voltage?

What BMS are you running?

What is the outside temp lows? You thinking the cage never goes under 22c doesn’t make it so.
It was a maintenance day and unfortunately we exchanged polarity of the terminals from the battery to the charger and it went PUFFF.
This is a PV SCC
BMS has always worked fine at 55.2V

Regarding temperature.... I am living in Dar es Salaam just 6degrees South of Equator which is always warm/hot weather
 
Looking at those cells and being it wasn't a single cell that bloated but multiple cells it certainly seems as if they were receiving some sort of voltage even if it was miniscule, which over a period of time can over charge and bloat the cells.

There was noway that someone could flip a switch or something even not realizing it. I would think if it was an internal short in a cell (but this is multiple cells) that they would keep going and release some magic out from inside. I suppose stranger things have happened but not without help.
 
The battery bank is always outside my house in the cage where temperature is between 22C - 32C. No ventilation issues
How can this happen without any load? I feel like your battery supplier will get into some trouble now... it doesn't seem like your battery storage conditions are particularly bad. A typical battery pack should not bulge to this extent, even without battery compression.
 
Was the orientation of the cells on their sides? IE terminals pointing out, not up?

If the cells were on their side, were the terminals up and down or left and right?
 
How can this happen without any load? I feel like your battery supplier will get into some trouble now... it doesn't seem like your battery storage conditions are particularly bad. A typical battery pack should not bulge to this extent, even without battery compression.
It is sad and very discouraging.... The Chinese supplier will definitely jump into their usual funny conclusions.....
 
Measure voltage on each cell. They are likely below 2V per cell. I have same type blue plastic case cells and one bloated like that too. It was left sitting disconnected for a year and self discharged to 0.3V. Looks like same thing happened to your cells. In the future use some kind of battery trickle charger to keep them at 3.35 V per cell. Small 10W solar panel with linear regulator should work.
 
Measure voltage on each cell. They are likely below 2V per cell. I have same type blue plastic case cells and one bloated like that too. It was left sitting disconnected for a year and self discharged to 0.3V. Looks like same thing happened to your cells. In the future use some kind of battery trickle charger to keep them at 3.35 V per cell. Small 10W solar panel with linear regulator should work.
I will be recharging them in next 5 days.... hopefully the SCC will be here by then....
 
I’d be checking the cell voltage before attempt to charge them.

Also IMO that’s not minor bloating, that’s almost catastrophic failure.
 
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