Mppt Bluesolar on Lfp batt. Bad charging

[f1991]

This is a CONCERN, such heat discoloration is NOT a good sign, looks scorched (burnt) from overheating.
Cells appear to be EVE 230AH.
Try to take a clear photo of the QR Codes and one of us can decode it. Alternatively, the Google Play Store has a "LiFePoQR Battery QR scanner". that will give you the details.

View attachment 113753

I found these white traces quite strange too but scraping it seems that they are residues of the glue that was used to seal the battery box. There are 3 temperature sensors on the battery, and they have never exceeded 35°C
I have looked at the EVE cells on the internet, and it seems that they are just grade B cells?

I will clean the white marks and watch that they do not come back. Thanks

 

[f1991]

Ah, I can understand the language barrier issue.

This page and document are absolutely outstanding.

Top Balancing "How to"

For current best practices on top balancing cells, please watch the video and download the PDF at the following page: Top Balancing Cells Using a Low Cost Benchtop Power Supply If you are interested in a more general tutorial of what balancing is about and *Why* to balance, check this out...

diysolarforum.com

I would for sure top balance this setup. take it apart and wire the cells all in parallel. I bet it wasn't originally and it's likely the root of your problem. But I'm new to this and hopefully someone with more experience can weigh in.

Then you get a DC power supply - set it to exactly 3.65....set with a digital voltmeter. Then let it go until the Amps in are zero and the V rises to 3.65.

Okay, thanks for the advice I will try to get a DC Charger. My only source of electricity is this battery, I will have to find a way to power the DC charger. Thanks for the document I will translate it as soon as possible.

 

[On_The_Road]

This is a CONCERN, such heat discoloration is NOT a good sign, looks scorched (burnt) from overheating.
Cells appear to be EVE 230AH.
Try to take a clear photo of the QR Codes and one of us can decode it. Alternatively, the Google Play Store has a "LiFePoQR Battery QR scanner". that will give you the details.

View attachment 113753

I bet the white stuff is adhesive?

 

[f1991]

I bet the white stuff is adhesive?

Yes, it seems to be the glue that was used to seal the box

 

[f1991]

@On_The_Road
Is it possible that all these problems are related to the quality of the cells?
They are grade B EVEs but is it possible that they are second-hand cells?
I noticed that if I consume 80a for a few seconds the cells go from 3.36 to 3.28 instantly .
Which would mean that I consumed half the battery for a few seconds of use. I thought that the voltage would go up when the consumption stops but this is not the case

 

[On_The_Road]

@On_The_Road
Is it possible that all these problems are related to the quality of the cells?
They are grade B EVEs but is it possible that they are second-hand cells?
I noticed that if I consume 80a for a few seconds the cells go from 3.36 to 3.28 instantly .
Which would mean that I consumed half the battery for a few seconds of use. I thought that the voltage would go up when the consumption stops but this is not the case

Maybe - but the lack of a top balance is a variable you need to eliminate first.

 

[f1991]

Maybe - but the lack of a top balance is a variable you need to eliminate first.

Yes i search for a DC charger and a power source for top balance.But the battery reacted strangely in recent days. It discharges as if it weren't really a 230ah or the cells are tired.

 

[f1991]

Maybe - but the lack of a top balance is a variable you need to eliminate first.

Hello ! I started charging at 3.65v.I bought a 0-30v and 0-10a charger but if I set it to 3.65v I am limited to 3.80A. its likely to take a week for a full charge.
I just have a question, when I test the voltage with the multimeter, I have 3.55v at the charger outputs and 3.32v at the battery terminals. Is this normal or should I adapt the voltage of the charger for having 3.65 to the charger output ?
Thanks

 

[On_The_Road]

As long as you set the charger to 3.65 exactly - with your multi meter then connected it to your battery it's good.

The volts will sag....what you're seeing is normal. You know it's done with the amps drop to zero and the volts rise up to 3.65.

If you want to speed things up you could reassemble the pack to 4S and hook your bms back up. Set the BMS to cut off at say 3.4 or 3.45. This way it charges to nearly 100 percent.

The disassemble and put it back together as 40 like you have now. And finish the top balancing at 3.65.

 

[Substrate]

I just have a question, when I test the voltage with the multimeter, I have 3.55v at the charger outputs and 3.32v at the battery terminals. Is this normal or should I adapt the voltage of the charger for having 3.65 to the charger output ?

THIS is a recipe for disaster the way you describe it.

WITHOUT ANY BATTERY ATTACHED, measure the voltage of the programmable charger leads with the multimeter, adjust to your desired voltage, and never touch that voltage knob again.

Attach to battery. You may not like the current, and the voltage on the charger may seem to drop. This is normal. Do NOT be tempted to tweak the voltage again. Because at the END of the charge process, the battery and charger will eventually be at your initial voltage setting.

Those who tweak their voltage after a battery has been attached to try and make for more current flow initially and save time, can easily ruin the battery at the end of charge when the voltage rises well beyond their initial setting.

 

[Bud Martin]

Hello ! I started charging at 3.65v.I bought a 0-30v and 0-10a charger but if I set it to 3.65v I am limited to 3.80A. its likely to take a week for a full charge.
I just have a question, when I test the voltage with the multimeter, I have 3.55v at the charger outputs and 3.32v at the battery terminals. Is this normal or should I adapt the voltage of the charger for having 3.65 to the charger output ?
Thanks

1) it sound like you have too much Voltage drops on the wires.
2) Are you using the junk wires with alligator clips that come with the power supply? If you did you need to change to at least 10ga wires and ring lugs.
3) Can we see the pictures?

 

[f1991]

THIS is a recipe for disaster the way you describe it.

WITHOUT ANY BATTERY ATTACHED, measure the voltage of the programmable charger leads with the multimeter, adjust to your desired voltage, and never touch that voltage knob again.

Attach to battery. You may not like the current, and the voltage on the charger may seem to drop. This is normal. Do NOT be tempted to tweak the voltage again. Because at the END of the charge process, the battery and charger will eventually be at your initial voltage setting.

Those who tweak their voltage after a battery has been attached to try and make for more current flow initially and save time, can easily ruin the battery at the end of charge when the voltage rises well beyond their initial setting.

hi, thanks for your help. I made the connection as you said. I adjusted the charger then connected to the battery.
I had no change on the charger after the connection to the batteries. The voltage fluctuated between 3.64 and 3.65 and the Amps remained at ~3.96
My multimeter still indicates that 3.57v at the charger output.
EDIT: Just after installing the ring connectors instead of the alligators I redid the procedure and the amps are now at 5a

 

[f1991]

1) it sound like you have too much Voltage drops on the wires.
2) Are you using the junk wires with alligator clips that come with the power supply? If you did you need to change to at least 10ga wires and ring lugs.
3) Can we see the pictures?

Hi. Thanks for the advice, I actually use the original alligator clips. I will cut out the alligators and replace with ring terminals
Édit : I installed the ring connectors. I still have 3.57 out of the charger but there is now 5A coming out

 

[Bud Martin]

Those wires that come with the power supply is around 16ga (some are even at 18ga), way too small for what you are trying to do and it does not help using the alligator clips either.

 

[f1991]

Those wires that come with the power supply is around 16ga (some are even at 18ga), way too small for what you are trying to do and it does not help using the alligator clips either.

Ah okay, I misunderstood your message, I'll try to find thicker cable. the more the battery is filled, the more the amperage goes down.
It's been almost a week of charging and still has 3.34v on the cells.

 

[f1991]

Hello. the charge is finished since this morning (finally!)
The charger amps are down to zero but the cells are only at 3.62.
I hope it's going to be ok, I'll set up the BMS and wait for the sun to see if my problems are solved

 

[f1991]

@On_The_Road @Bud Martin @Substrate
Hi. I wanted to ask you a question, is it normal for the load to be at a maximum of 3.62v?
And today the cells are at 3.59v even though I didn't use them.
Thank you very much for your help

 

[f1991]

hello, I reassembled the battery in 12v. the cells are at 3.55v therefore 14.2v overall.with the multimeter I have a voltage of 13.75v at the battery terminals. I think it's not too normal that the voltage is not equivalent to the voltage of the cells....
If ever someone passes by to reassure me about the state of this battery that broke my head. Thanks

 

[mikefitz]

Provided your voltmeter is reading correctly it seems the BMS has detected a protection situation and disabled the battery charge path.

Try loading the battery to lower the voltage.

Previous posts suggest the cell overvolt value is 3.50 volts, your cells are higher than this.

 

[f1991]

Provided your voltmeter is reading correctly it seems the BMS has detected a protection situation and disabled the battery charge path.

Try loading the battery to lower the voltage.

Previous posts suggest the cell overvolt value is 3.50 volts, your cells are higher than this.

hi @mikefitz
to finish this story, I broke the screw of a cell by tightening the bolt too hard. so I have a cell out of service. obviously no European seller sells these cells.
So it's going to end up in the back of a closet and I'm going to go back to agm batteries.
Thank you all for your help and advice