I finally received my 12 Eve LF280K cells from Amy Wang a week ago or so. I've been busy, so haven't had the time to work with them much. This weekend I was able to top balance and capacity test 4 cells. I followed the instructions on this forum for top balancing by first putting the cells in serial, added the JBD BMS, that I also ordered from Amy, (4s 12v 120a), and charging with the benchtop power supply set to 14.2v and 10a. After one of the cells hit 3.65v, the BMS shut down the charging. The first picture is a screen shot from the app that I downloaded from Overkill Solar for the 120a JBD BMS. It shows the first cell in red to hit 3.65.
After that, I arranged the cells in parallel and top balance with the power supply set to 3.60v and 10a.
Once it would take no more amps, I put the cells back together in series and added the BMS. This is what the app looked like before the capacity test.
During most of the test, the voltage diff stayed around .007v. As the test neared the completion, the voltage diff began to widen until the end.
The capacity test ended with the pack getting almost 281Ah, so I guess that is as advertised.
I am now charging the pack back up and I've seem the BMS start to do some balancing, so the cells are starting to get back in line with each other. I am still new to this, but during the time I waited for the cells to arrive, I read a ton of posts here and watch a bunch of videos on YouTube. Does all of this seem about normal? This is my first battery build and I don't want to screw it up!
After that, I arranged the cells in parallel and top balance with the power supply set to 3.60v and 10a.
Once it would take no more amps, I put the cells back together in series and added the BMS. This is what the app looked like before the capacity test.
During most of the test, the voltage diff stayed around .007v. As the test neared the completion, the voltage diff began to widen until the end.
The capacity test ended with the pack getting almost 281Ah, so I guess that is as advertised.
I am now charging the pack back up and I've seem the BMS start to do some balancing, so the cells are starting to get back in line with each other. I am still new to this, but during the time I waited for the cells to arrive, I read a ton of posts here and watch a bunch of videos on YouTube. Does all of this seem about normal? This is my first battery build and I don't want to screw it up!