Hi,
I run a REC master/slave BMS for a 96 cells/40kWh stationary battery.
As described in the attached documentation, there is a pretty clever mechanism built into REC master device to close the charging with a reduced current at the end of the balancing. If the BMS temperature is not overheated and the cells are close enough, the SOC is calibrated to 100% (netto) at the end of every full charge at the CHAR voltage.
So far the theory or documentation....
However, based in the documentation I am still puzzeld how to set the parameters and do not get the desired behavior.
Balancing in charge regime shall start for the cell of higest voltage when they come above 3,995V. This works.
Then, I'd like to have the whole pack ideally balanced and stop charging at 4,084V/Cell. This is my 100% SOC (netto). There is still enough room up to the max voltage of 100% brutto (4,23V). So I set CHAR to 4,084V.
The 4,146V is the max Voltage I want to have cells charged if balancing does not succeed perfectly. Not sure if this is the right meaning of this variable?
Do I understand the setting right?
Today charging simply drops from max current to zero, when the first cell reaches the CHAR value.
I see no slow current decrease to 1.1Amps as described in the documentation. I have also tried other hysteresis values (CHIS) up to 0.1V wihtout success.
Any experience is appreciated.
Sunny Greetings
Stefan
