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Problem charging batteries via bms

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TheKing:
I did it with the notification.
Yesterday I took all the cells out of the vehicle with the intention of balancing all 16 at once. While taking them out, I noticed that there were a few swollen cells, one more and two less (barely noticeable).
This is already another problem.
I plan to test all the cells with a load from a vehicle starter on 12v, 4 cells .... with meters on each cell to show the load voltage.
I have no idea how to load one cell at a time ... Likewise, I don't have such a load, so this is a kind of compromise.
I would like to hear your brief opinion that they are on the right track, or maybe you have better solutions
Best Regards,
Jovan

Bikemad:
Hi Jovan,

I guess that the swollen cells will be from positions 11~16, as these are the cells that appear to have been overcharged the most:



If you are going to use a car starter motor to load a pack of 4 cells in series, it will need to be turning over an engine to put a high load on the pack.
An unloaded starter motor spinning freely will not draw much current.

Some garages may still have an older style resistor type battery testers that puts a 100A load directly across the battery terminals to check the voltage drop under load. It might be worth asking your local garage to see if they have one, and if they would let you use it.

Alan
 

TheKing:
Yes, that's right, those 11-16 are swollen. I checked the first 8 cells, they are all balanced and visually ok.
I'll try to find a resistor type tester today, should find something...or some older hard starting vehicle. Ok ... greetings and see you later

TheKing:
I'm sorry that I'm a little later ... sometimes there are more private obligations, even some travel days through the neighboring countries  :)

Just to let you know, while I was waiting for the new BMS last days ... I tried to somehow load the cells with a load, I couldn't find any of those old resistors ... so I put a 90A starter for car engine on 12v where all the load cells, group and individually, did not show some significant voltage drop at 90A load. Maybe it's a small load for 300A cells?

Anyway, I assumed that I had to buy at least one cell, and ordered it... In the meantime, with new balance wires (to avoid any bad contact)... I installed the new BMS with active balancing.

To begin with new BMS, let me say that it works... but shuts down when charging because, seems, the swollen cell reaches 3.65v first... Maybe I should raise the upper limit to 3.9 or 4v?

When discharging, it works under a small load of up to 100A ... but when it is higher, sometimes it turns off, sometimes it doesn't!? ... I can't understand the connection why it turns off, all the setting parameters are ok, min/max current, min/max voltage, etc.
Hopefully when I install the new cell, everything will fall into place.
Ok, when there are new events I will let you know ... greetings and have a nice day
Jovan

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