diy solar

diy solar

How to diagnose; weak cell or faulty bms? (Bigbattery 100Ah 24V)

I used the inverter/charger to bring the whole pack up to a high SOC, all cells (pouches) except 1 and 6 got up to 3.65V. cell 1 was 3.3something and cell 6 was 3.4something. So I'll charge those two separately up to 3.65V. Just wondering if I should have the BMS unplugged while I do this. I currently have BMS connected, but I suppose this means it could take much longer to bring up SOC in 1 & 6 if I'm simultaneously fighting the BMS which is trying to balance?
 
i guess the cells are pouches and the battery is an 8s5p config of pouch-groups. so what I'm charging is a 5p pouch-group. the bonded terminals are accessible
 
Yep that's what I have also but since the 5 pouches are connected parallel then in series, I thought they couldn't be charged as separate cells :unsure: Ok, If so I've learned something very helpful today. The ability to top balance each pack individually.
I did have an issue also with a cell running away while charging and after trial and error I found charging at 28.4-5v (28.8v is max) solved the HVD from the BMS. Running a capacity test afterwards show they produced the full rated capacity. Cells came together .07mv
Between both knees. Then the oddball showed it self again but it delivered what it was supposed to so I’m happy. 8CAC3384-DB56-4059-85E0-8AFA1CCD8587.jpeg
 
This scares me as I was planning on buying 2 big batteries. If this is the type of issues going on, with minimal support I might just skip them.
 
You must log in or register to reply here.
Back
Top