How are BMS' connected and work when charging?

[Fordulike]

Can I just confirm, that a BMS will control the charging shut-off in a bank of batteries, that are connected in series as a total, and not individual cells?

I.e. in a 13s4p pack, the BMS will be connected to each string of 13s, so 4 physical connections?

I just confused myself rereading that, so I hope you get what I mean

 

[soundwave]

 

[Deleted member 4366]

The BMS has 14 connections for 13S. that's ground and then the positive from each cell-group. It has to control the voltage of each cell-group to switch off charging when one goes too high and switch off discharging when one goes too low. Here's a schematic o a 10S4P battery:

 

[awol]

Are BMS's any good at accurate full balancing?
I mean, can one cell be low with all the rest high enough to switch the charger off?
My old li-ion battery is becoming low on power around 37.5v so am guessing maybe one cell is lower and it all need a good balancing.

 

[Deleted member 4366]

That's possible. Check with a multimeter after charging.