How many 1S BMS in series

[fostr01]

I got some lipo cells 3.7V 2.2AH X 2 each with their own BMS connecte to the two parallel cells, my question can these cells work just as they are or do i have to remove the BMS board, and then i could use one BMS in a 14S10P or 20S14P to achieve the kwh i need, secondly i hooked up a 20S pack and i noticed one cell in the bank charged up before all the other cells shutting down the charging to around 77 volts, do i have to remove each 5A BMS per cell and just use one 20S for the complete pack so i can get 84 volts finallly


All comments are welcomed for education

Thanks

 

[gnubie]

At a guess the transistors in the built in BMS will not have very high voltage ratings so if you stack them up and a BMS decides to disconnect for some reason the transistor(s) in that BMS will get higher than rated voltage across them and die. Replacing them with a single BMS would be a better option IMO.

Are you building a bike battery? Wondering about the high voltage.

 

[fostr01]

At a guess the transistors in the built in BMS will not have very high voltage ratings so if you stack them up and a BMS decides to disconnect for some reason the transistor(s) in that BMS will get higher than rated voltage across them and die. Replacing them with a single BMS would be a better option IMO.

Are you building a bike battery? Wondering about the high voltage.

I like the feedback you gave, and ill consider removing the 20 BMS and use one instead