I think mine are going to take forever to top balance... to speed up the process, put them in 12v configuration and ran the Lithium charger on it. It pulled about 26amps until one cell started the climb. It got to 4.2Vdc before I realized what was going on. Wasn't there long , hope I didn't hurt it. It did settle right back to 3.33Vdc as the rest of them.
Lesson learned.. if you are going to charge like that.. put the BMS on it.
I am in no hurry, so I put the lab supply back on it and it is drawing 3.85A. I am sure it will do that until the cells start to climb towards 3.6V.
If it does not climb in a day or two more, I am going to put the BMS on and quick charge. Didn't think about it too much, but in parallel, these are 3.33V at 1120aH.. so even if the batteries were mostly full.. it could take days at this rate.
Just learning my way around these LiFePo4 batteries. Interesting is that if I put my PS on 3.3V, it does not draw current, but that makes sense on the PS since it does not see a load. These batteries have such a flat curve before the get full and voltage climbs. That is why they need to slightly overcharge at 3.6V.
Also... good example of why BMS is needed and why the need to be balanced.. one battery got full first and voltage climbed too high while others stayed at 3.3V. BMS would have shut that down.. glad the Progessive Dynamics halted charging and cut of current at 14.4 volts as it was suppose to before I noticed.
Which leads me to another dilemma... do not want solar to charge directly on batteries without going through BMS, but with a common port BMS, I am wondering if it totally cuts power in certain cases because the Solar Charger needs 12vdc to run and regulate the solar power coming in from the array. Could hurt the Solar Charger.. hmmmm?
Maybe should have got a BMS with separate charge ports, but then the Shunt and battery monitor would never pick up on the solar charging and coulomb count will always be off and state of charge wrong?
In the CTC I am going to hook up solar to charge through BMS on common port unless I find out otherwise. I'd think the case with solar charger being online with the BMS cutting off ground return would be extremely rare. Not sure how the off the shelf LiFePo4 batteries are configured, but they must be common port as the only come with 2 terminals.
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