Internal BMS disables discharge – need help rebuilding 4x 12.8V LiFePO4 into one 51.2V 200Ah bank

[blerimdemaj]

Hello, is there anyone here with experience building a LiFePO4 battery bank who could help me?
I have 4 x 12.8V LiFePO4 batteries, and I am thinking about dismantling them, taking out the cells, and rebuilding them into one single 51.2V 200Ah battery bank with an external BMS with communication.
My current problem is that the internal BMS does not hold the load during discharge. As soon as I put a slightly bigger load on it, it goes into disable discharge.
My questions are:
Is it a good idea to combine these 4 batteries into one single battery bank?
What should I be careful about when combining the cells?
What BMS do you recommend for 16S 51.2V 200Ah?
Do I need to balance all cells before assembly?
Has anyone here done this kind of conversion successfully?
Any practical advice or real experience would be greatly appreciated. Thank you.

 

[j bjork]

It sounds like there might be a problem with a cell or something if the bms cuts, or are you going over max currents?
If you want to build one battery of them, make sure to test the cells first so they are the same capacity etc.